The Leonine Heresy

by Sharrowkyn

Inspired by the Roboutian Heresy, this is the tale of Lion El'Jonson's fall to Chaos as he leads half of his brothers (and not necessarily the ones you might think) in rebellion against the Emperor. All Index Astartes entries have been completed, and now we are journeying through the various War Zones of the 41st Millennium.

7. Index Astartes: Thousand Sons

Chapter 7: Index Astartes- Thousand Sons

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Index Astartes- Thousand Sons: Conjurers and Cabalists

The undisputed masters of sorcery, the psyker-lords of the Fifteenth Legion are by far the most individually powerful among the legions by virtue of their mastery of the Warp. Chosen by the Architect of Fate, the Thousand Sons were slaves without even knowing it, puppets of Tzeentch even before they purposefully turned their backs upon the Emperor. They are both masters and puppets, powerful and powerless, deceivers and deceived, and well do they know it. They have mastered the intricacies of the Warp like no other, and their skill in shaping reality to their twisted whims is unsurpassed by any other. However, such power has its price, and the Fifteenth Legion has paid dearly, and number little more than a thousand true Astartes, each a sorcerer of incredible might. The rest of the legion are near-mindless beasts, enslaved to the will of others just as their masters are enslaved to the will of Tzeentch. Every wicked deed and inexplicable action is performed in service to the dark schemes and foul plots of the Ruinous Powers, a convoluted web of intrigue that every sane individual fears as it creeps ever closer to completion.

Origins: The Arcane Brotherhood

Like all the other Legions, the Thousand Sons have their origins upon Terra, crafted through the arcane genetic science of the Emperor of Mankind. The Fifteenth Legion was unique from the outset as it was intentionally specialized, whereas the other legions only gained their focus later after finding their primarchs. The aspirants for the Fifteenth proto-legion were taken from the Achaemenid Empire, one of the first regions to fall under the Emperor's control, and as such had been loyal for nearly a century before the genesis of the Astartes Project. The Master of Mankind traveled the Empire, personally selecting aspirants from various families whom his foresight had shown great potential in. These recruits were taken to the gene-labs underneath the Himalazian Mountains, and implanted with the various organs required to become Astartes. The Emperor's foresight was powerful indeed, and 99% of aspirants successfully received the gene-seed to become Astartes, and so the legion quickly grew to be around one thousand strong. While other legions had to wait until they reunited with their primarchs, the Fifteenth received the moniker of 'Thousand Sons' from the Emperor himself, the first legion to receive such an honor.

After completing their training, the Fifteenth Legion was deployed alongside the other legions in the Emperor's Fleet, and fought honorably by his side. Within a few years, the Legion's specialization showed itself, as the vast majority of legionaries began to display psychic powers. Though others were initially alarmed, the Emperor assured the legion this was part of his design, and appointed Ohrmuzd Ahriman as the Legion Master. The legion was separated into its own Expeditionary Fleet separate from other forces, and they brought many worlds to compliance over the next seventy years through their astounding abilities, though many were uneasy about the manner in which they did so. The Fifteenth quickly became a target for criticism from both civilian and military figures. The primarch Leman Russ, the second of the Emperor's sons to be found, was quick to denounce the Fifteenth as a coven of witches whose methods brought shame to the Imperium. Imperial Army generals would actually turn down aid rather than be seen as associating with them. Thus the Thousand Sons operated mostly on their own, though the rejection began to weigh on them.

They began to draw more deeply from the Warp, utilizing riskier psychic powers in order to speed up compliances. A preferred tactic of theirs was to seed a prospective world with Astartes, who would then act in concert, bringing the whole planet to its knees in servitude, their minds scoured of the ability to resist. While undeniably effective, this left the population nearly useless for anything but the simplest of tasks, and so the criticism continued unabated. As a result of these more powerful spells, the Thousand Sons began to suffer from a flaw in their gene-seed. After casting a particularly potent ability, the unlucky legionary in question would begin to devolve and mutate, screaming as new limbs and organs mutated from within him, leaving the Astartes a gibbering monster who had to be put down by his brothers. Such mutations came to be called the "Flesh-Change", and became one of the legion's many secrets, though this was made easier by their allies' refusal to campaign with them. The legion, having grown to nearly ten thousand, began to succumb more rapidly to the curse after 860.M30, and within nine years, there were barely a tenth of the legion left. This curse was to change, however, with the return of their primarch: Magnus the Red.

The Crimson King

Each and every primarch was carefully crafted and designed by the Emperor himself with specific purposes in mind. Some were leaders of men whose example would inspire those around them to greatness, such as Horus Lupercal or Roboute Guilliman. Others were savage fighters before whom no foe could stand, such as Angron or Sanguinius. Each and every one was deeply connected to the Immaterium, even if they themselves chose not to recognize it. However, there was one who stood apart from his brothers, even from their conception: Primarch XV, who would later come to be known as Magnus the Red. The inhabitant of this pod was unique in that it was already thinking and learning, despite being not even a child yet. Thus when the pod was suddenly, like all its brothers, thrown into the warp by the machinations of the Ruinous Powers, the tiny mind inside was gripped by terror and helplessness like no other. The pod hurtled through the Warp, fiends of every description clawing as they attempted to breach the Gellar fields protecting it. His small mind reached out, but no aid was forthcoming, and all he could hear was malicious laughter. The pod finally came to rest upon a desolate backwater named Prospero, just outside the border of what would later become Segmentum Solar.

Such a planet was not one any would settle willingly: an utter wasteland, most of Prospero's surface was covered in vast deserts, while its few cities were built in the mountains, or along small rivers and oases. As befits such an unwelcome realm, the bulk of its inhabitants were descended from criminals and outcasts, who had been forcibly marooned while their vessels traveled on without them. Many of these rejects were those touched by the Warp, witches and magicians whose powers made them a danger to others. When the Age of Strife began, powerful warp storms cut Prospero off from the wider galaxy, and aetheric energies bathed its surface, increasing the powers of the inhabitants and their descendants exponentially. Daemon incursions were rampant, and only those strong enough to master their own minds survived, building fortified tiered cities with powerful runes etched on every surface to contain and ward. Each city was ruled by the most powerful sorcerer, who ruled over cabals and fellowships of lesser magicians, and below them labored those seen as lesser: any who lacked the gift or whose powers were lacking. The largest of these cities was known as Tizca, the City of Light, built within a more temperate mountainous region. When the pod landed near the city, its inhabitants came out to investigate the presence they had felt and foretold. They discovered a boy with reddish-brown skin, long hair, and the most powerful mind any of them had ever seen.

The boy was taken in by the leader of Tizca, a man named Amon, and he was named Magnus. The inhabitant of Pod XV was a quick study, and swiftly surpassed his teacher in both psychic prowess and physical size. Indeed, he grew to tower over all, and none could best him in either martial contest or in mastery of the Great Ocean, as they called the Warp. However, this brought him little joy, for he was constantly melancholy. Magnus felt like there was a great absence in his life, as though he was meant to be in contact with someone, though he knew not why. Though he was less than a year of age, he took over governing Tizca, Amon stepping down in recognition of his pupil's ability. Magnus had always felt that these primitive sorcerers were limiting him, their educational techniques as blinders keeping them from true greatness. If they had power, why not use it? He began to transform Tizca to fit his way of thinking, and quality of life improved, especially for the sorcerous elite, who proved most able to fulfill the primarch's ideas and vision. However, expansion of Tizca swiftly came to a halt with the return of the Psychneuein. As settlers worked to expand their city beyond the protective walls, massive wasp-like creatures began to descend in swarms. These warp-based entities were attracted to powerful minds and use of psychic powers, and vast swarms buzzed out from crystalline caves in their thousands, feeding upon the brains of those unlucky enough to be caught by them. As Tizca began to be overrun by the aethereal insects, Magnus meditated within the great crystal pyramid at the center of the city, his mind searching the Great Ocean in hopes of finding knowledge to defeat them.

His astral form was a thing of radiance, a blinding light that attracted the gazes of a million million eyes as it swam in the endless depths of the Great Ocean. Magnus had never traveled this far from his body, but then it wasn't possible to determine how far he was moving in any case through the Sea of Souls. Momentum meant even less, and so despite traveling with incredible speed just a second ago, Magnus now found himself completely still, stopped inside a crystalline room made from the hopes of a long-dead civilization. In front of him floated an orb of blue light, which spoke to him in a voice that was many voices, with the wisdom of the owl and the derisive caw of a raven.

"I can grant you the knowledge you seek..."

When Magnus opened his eyes, he felt a rush of power suffusing every fiber of his being, like nothing he had ever felt before. Moving by instinct, his mind reached into the pyramid, using it to focus his power and amplify it. Bolts of white lightning shot forth toward every Psychneuein in the city. The psychic defenders of the city felt their powers increased as well, and all felt hope once more. The predators were charred and burnt, their physical bodies utterly ruined while their psychic essence was pulled out and drawn back toward the pyramid. As the last wasp fell, Magnus felt the rush of power fading. With this enemy defeated, he felt as though nothing could stop him now. It was his knowledge and power which he had so skillfully obtained, and clearly fate smiled upon him.

When word of his deeds spread to the other cities, they swiftly submitted, and Magnus became the undisputed master of Prospero, and he took for himself the title of Crimson King. From his grand pyramid amidst the obelisks of Tizca, the primarch ruled over a network of colonies, each controlled by sorcerer-satraps Magnus appointed over them. Those who had fallen were of no concern, weak and quickly forgotten as Magnus led a grand expansion of Tizcan society. Expeditions were sent to the many ruins that dotted the deserts of Prospero, retrieving long-forgotten lore and hauling it back to the ever-expanding Grand Library. While civilization thrived under his rule, Magnus continued his aetheric research, diving deeply into the Great Ocean, obtaining great power even as he searched for the entity that had granted him power. The sorcerous might had soon faded away after he had defeated the psychneuein, but the memory of the experience did not, and Magnus was determined to get that power for himself, one way or another.

Prospero thrived beneath Magnus's rule for many years, and the population began to increase rapidly as the desert was transformed into verdant farmland. The primarch set up a series of colleges, each specializing in a particular branch of psychic mastery, and satellite schools soon proliferated across the cities, forming a vast network across the planet. Thus Prospero became a shining beacon of light within the Warp, stilling the ever-tumultuous Great Ocean around it. Such calm soon caught the attention of travelers crossing the Sea of Souls, traders and explorers of every description. Word began to spread of Prospero, rumors which eventually made their way to those who would understand the implications of such an unusual occurrence.

As Magnus was meditating within his pyramid, he felt a massive presence in the Great Ocean approaching Prospero, waves of golden light rippling and disturbing his concentration. The skeins of fate all spoke of this luminous being's approach, and so Magnus was unsurprised when a massive ship arrived above his home, a golden warship that stretched across the length of the entire city. In a brilliant flash an armored figure appeared before him. Magnus was stunned, for this figure was more powerful than even he, and the man introduced himself as Magnus's father, the Emperor of Mankind. Magnus's mind raced: outwardly he feigned joy and obedience, a difficult gesture as this was the first time in many years that anyone had even come close to surpassing him. Inwardly though, he fumed. Somehow or some way, Magnus would surpass this man who called himself his father.

Communicating with incredible speed by using his prodigious mental abilities, the Emperor impressed upon his son the knowledge he would need to prosecute the Great Crusade, and thus Magnus did not require the months or years of instruction as his brothers needed. This was both a blessing and a curse: Magnus was able to go straight to his legion in their time of need, though who knows how things might have turned out had the Emperor taken the time to instruct Magnus as he had all the other primarchs before him. He was the tenth of the Emperor's sons to be found, though few of his brothers wished to have anything to do with him on account of his legion. Without exception they were disappointments to the Crimson King. Ferrus Manus, Rogal Dorn, and Angron distrusted the powers of sorcery; Guilliman looked down upon Magnus as he did on everyone else; Vulkan and Jaghatai Khan were simply too far away to return just to greet their new brother. Only the first-found, Horus Lupercal, seemed to want to have anything to do with him. Horus greeted him as a brother, eagerly asking Magnus questions about his homeworld and all manner of things. Despite Horus's lack of the Gift, Magnus found himself liking this brother.

Less joyous was Magnus's reunification with his sons. Barely a thousand Astartes gathered to greet him when he journeyed to meet them for the first time. The flesh-change had decimated their ranks, and they were nearly the smallest legion, beaten out only by the blighted Third. Magnus listened with horror at the words of Legion Master Ohrmuzd, who told him of the curse which had plagued the legion for decades now. Magnus knew he would need a powerful legion like that of his brothers if he was to ever gain the power of the Emperor, and so the curse must be addressed. The lessons of his past flashed through his mind, and he knew what he must do. Gathering his Thousand Sons, Magnus created a vast ritual circle comprising ninety-nine rings. Those of his sons who were psykers stood beside him, acting as amplifiers for this dangerous spell. Magnus had long desired to perform this ritual, though the people of Prospero had proved too weak to sustain it. The Fifteenth Legion acted as one, and Magnus's mind was propelled deep into the Great Ocean.

The astral form of the primarch shook with excitement. Finally he would find that being again, and either take its powers or force its aid once more. He passed through shoals of every emotion imaginable, saw colors that could not exist in the real world, and felt the ravages of time flow and recede. All of this was secondary, however, to his goal: to find that crystalline room once more. His form traveled trillions of years that lasted only a handful of seconds, and came to what appeared to be an ever-shifting crystalline maze. He did not hesitate before plunging into it, and quickly came to the familiar room once more, where the blue light floated. No longer a sphere, it appeared more as a torso with the slightest hints of limbs coming out from the sides and a mouth toward the bottom of it.

"Spirit, I have come to take your power once more. My sons and I require it and thus it will be mine. You will obey." Magnus's astral form stretched out a ghostly hand, and tried to siphon power from the entity. To his surprise, nothing happened. The spirit opened its mouth, and spoke with that same voice of many voices.

"The first is always free, but the second will come at a price. What will you give me for this power?"

"What do you desire?" Magnus realized with frustration he would have to bargain with this spirit for what he wanted.

"Nothing much, I only require a small sacrifice, an iota of your essence." The toothy mouth gave what it no doubt thought was a winning smile.

"Very well spirit, I accept. Increase my powers so that I might save my sons."

"You have a deal. I look forward to seeing you again." Magnus felt his astral form rushing back to his physical body, while all around him boomed the sound of laughing gods.

When Magnus arose from his position at the heart of the ritual circle, he beheld a scene of horror. Smoking ashes filled the ritual chamber, billowing from dusty piles on the floor that had once been proud legionaries. Horrific squealing echoed from other spots in the circle, where the Warp's infinite energies had proved too much to sustain and rampant mutation had erupted from within. Nearest to Magnus was the charred corpse of Legion Master Ohrmuzd, who had been subjected to the greatest amount of energy in his position in the second ring, and another legionary knelt beside the body. Magnus recognized this son as Ahzek, the Legion Master's twin brother. The primarch reached a hand up to his face, and felt only smooth skin where his right eye had once been, though his vision seemed unimpaired. Using the circle as a conduit, Magnus forced a wave of energy out from him, which struck every legionary around him, and they all staggered as they felt the mutagenic energies lurking in their souls and bodies begin to recede. Magnus had saved the legion from sure extinction, and now it was time to join the Emperor's crusade so that he might gain the power he needed to supplant his father.

Great Crusade: Didacts and Barbarians

The flesh change was now gone, but the bargain Magnus had made did not bring back any who had already fallen. With the death of the Legion Master and so many others, Magnus knew he would need to rebuild his legion, and so he turned to Prospero. The Thousand Sons came to their primarch's homeworld, and began mass recruiting drives. Magnus could not afford to be picky, and thus even those without psychic potential were accepted as aspirants. He would allow none of them to go to waste, and by utilizing dangerous Warp techniques, he turned back time, having found a way to de-age his former mentor Amon until his physical body was young enough to accept transformation into an Astartes. He offered to make Amon his First Captain, but Amon refused, stating he wished to remain a teacher, and so Magnus appointed him as Master of Recruits. In his place stepped up Ahzek Ahriman. Once unremarkable, he had seemingly added his dead brother's Warp-mastery to his own, increasing his already-prodigious psychic abilities nine-fold, and he was now second only to Magnus in terms of power. Magnus reluctantly appointed him as First Captain, but made no secret of his dislike for Ahzek, whom he considered a poor replacement for Ohrmuzd. Ahzek was deeply hurt by this rejection, and throughout the Great Crusade, fought to earn his father's acceptance.

With the return of their primarch, the Thousand Sons now prosecuted the Great Crusade with renewed vigor. Magnus's impatience made him a strict taskmaster, and his sons tried their best to meet his demands. His legion captured world after world, merciless to their foes and obsessively gathering all the knowledge the planet's cultures held. They specifically targeted worlds that they sensed were steeped in the Great Ocean, for those worlds would be most likely to have the type of knowledge they sought. As a result, they would skip over many promising worlds, recording their position on star-charts for conquest by other legions while they themselves moved on. This data was most commonly sent to the Iron Warriors and their gruff primarch Perturabo. Though he was found several decades after Magnus himself, the Crimson King and the Lord of Iron struck up a lasting friendship based around their mutual love of knowledge. Magnus quickly became the only brother Perturabo did not mind garrisoning worlds for, and their partnership resulted in many great victories.

Equally strong was Magnus's friendship with his younger brother Fulgrim. Due to their small size and inability to turn down aid, the Third had long been attached to the Fifteenth, and were overjoyed when they discovered the whereabouts of their progenitor. Found forty years after Magnus, the Primarch of the Third had reunited with a legion on the brink of destruction, just as Magnus had. Magnus himself had discovered Fulgrim upon the world of Chogoris near the galactic core, and kept his brother by his side for several years before informing the Emperor. Feeling sympathetic to his brother's plight, Magnus allowed his brother access to his legion archives, where Fulgrim learned of the ritual Magnus had performed. The Phoenician was grateful to his brother, and set off for parts unknown having gained the knowledge he sought. The Primarch of the Third Legion thanked him profusely for his help when he returned, armed with the knowledge he needed to save his sons, and together they revealed Fulgrim's presence to the rest of the Imperium. The Third and Fifteenth Legions began to campaign together, and the two remained close allies for many years.

In contrast to this lasting fraternal bond was Magnus's friendship with Lorgar, Primarch of the Word Bearers. The two had initially been close as they each sought understanding of the mysteries of the universe, but Lorgar's insistence on worshiping the Emperor led to the Monarchia Incident, and Magnus pitied his brother when he heard of his enforced exile. Years later, Magnus attempted to campaign with Lorgar once more, only for his brother to spurn his offer. Lorgar denounced his past, and tried to convince Magnus that his explorations of the Great Ocean were at best pointless. He flatly rejected Magnus's offer to tutor some Word Bearers in the use of psychic powers, and so Magnus departed in anger. As he turned to leave, the Crimson King thought he caught a glimpse of something off in his brother's aura, a strange blur around his head, but put it from his mind.

Lorgar's attitude was depressingly common among the other legions, many of whom still refused to work alongside the Thousand Sons, especially the Space Wolves. The brash Leman Russ made no secret of his distaste for those touched by the Warp, and the feeling was mutual. Magnus openly called his brother a barbarian and his legion a pack of savages, and never even attempted to reconcile with him. The Sixth and Fifteenth Legions fought together only once, during the Aghoru Compliance. The world of 28-16, also known as Aghoru, was a strange world, floating in a system surrounded by dead worlds. The human population was quick to submit to the combined might of two legions, and the Thousand Sons began to study their records. Their ancient texts spoke of an eldritch race of powerful beings known as the Elohim, who were imprisoned beneath a mountain upon the planet. When the Thousand Sons investigated this site, they discovered the mountain was artificially constructed, and surrounded by stones which blunted psychic abilities. His curiosity piqued, Magnus ordered his legion to investigate, only to be blocked by the Space Wolves. Russ denounced this mountain as a site of xenos witchcraft, and refused Magnus entry, stating his legion would destroy it.

After attempting to reason with his brother for a few minutes, Magnus grew impatient, and tried to force entry to the mountain. Gunshots rang out, and Astartes on both sides died to the bolters of their erstwhile allies. As the two primarchs tried to stop further violence, what the legions had assumed were mere statues grinded to life, responding to the bloodshed and began attacking all around them. Scholars believe these mysterious statues were none other than Aeldari wraith constructs, guarding an ancient site of their kind. While Russ led his men into battle, Magnus took advantage of the distraction to sneak into the mountain, his powerful magic blasting aside any constructs which blocked his path. Underneath he discovered a vast crystalline gateway, though nothing he did seemed to activate it or tell him how it worked or where it led. His inquiry frustrated, Magnus returned to the surface and ordered his men back to their ships. Russ denounced him as a coward for withdrawing, but Magnus simply did not care. His legion withdrew, and the two never fought side by side again.

Equally disastrous was the Fifteenth's campaign with the Eighth Legion. The Night Lords had struck Magnus as a pack of criminals and maniacs who brought only darkness in contrast to the light of knowledge which the Thousand Sons prized. Thus Magnus refused to fight with Curze, and was amused when the Emperor intervened again and brought his brother back to Terra for rehabilitation just as he had with Lorgar. Clearly his lesser brothers required guidance, and Magnus wondered who would be the next to feel the Emperor's judgment. Years later, Magnus crossed paths with his brother once more, and the two agreed to campaign together. He was unsure what to make of his brother now: gone was the psychotic madman, replaced by a quiet, focused individual wearing a blindfold. Magnus was certain his brother was using some sort of psychic ability to see, and noticed an auric nimbus around Curze's head, though there was no time to investigate it further. The gate found on Aghoru had become close to an obsession for Magnus, and his search led him to believe the Aeldari were involved in it. His investigations in the Warp led him to believe that the Zoah system held some of the answers they sought.

Thus the forces of the Eighth and Fifteenth Legions made planetfall, clashing with the locals who proved no match for two legions. After breaking the resistance, the two primarchs discovered a massive structure known as the Tower of Serenity which contained a vast library of arcane texts. Konrad was disgusted with the knowledge contained in the archives, and ordered his artillery to begin bombarding the tower. Magnus was furious, and ordered his brother to stop, but Konrad would not listen, stating the Emperor's law expressly commanded them to destroy such wicked knowledge wherever they found it. Magnus could wait no longer, and used his sorcery to jam the firing mechanisms of the Night Lord Siege Engines. As Konrad turned to find the source of the issue, Magnus teleported inside the Tower, ransacking the knowledge within while his sons blocked the Night Lords from entering. Konrad ordered his flagship to bombard the library but it was too late, as Magnus had already gained the information he needed. The Thousand Sons withdrew from Zoah just as they had from Aghoru, and Magnus ignored his brother's warnings that the Emperor would hear of this. The Crimson King had remained largely independent for decades now, and he would have little to fear from his father once he obtained the power which he now knew to exist. Magnus had finally obtained that which he had been searching for: knowledge of what lay beyond the gate.

Council of Nikaea: A Legion Rebuked

In addition to the esoteric knowledge of the mysteries of the Great Ocean, the libraries of Zoah and Aghoru both pointed toward the same thing: that some sort of Aeldari technology existed that allowed them to move without entering the Warp, a transportation dimension of some kind which contained a repository of knowledge unmatched in the entire galaxy. Magnus had crossed paths with the xenos several times during the Crusade, though they most often fled before they could be destroyed or captured. With a clear goal in mind, Magnus withdrew his forces and gathered them in preparation to assault one of their legendary craftworlds. The xenos were full of guile and trickery, and would no doubt have seen the assault of the Thousand Sons in their predictions of the future, but Magnus did not let that dissuade him. All that was necessary was to gather a large enough force to assure his victory no matter what.

By this time in the Great Crusade, the Thousand Sons numbered nearly sixty thousand Astartes, a far cry from the thousand or so that gave them their name. The flesh change had not troubled the legion since Magnus obtained the power in exchange for his eye, and he considered it well worth the trade. Magnus began to search for possible futures in the Great Ocean, seeking skeins of fate that might lead him to a craftworld, for the vastness of space meant he might never find one if he searched blindly. He decided the best course would be to attack Exodite worlds, those primitive backwater worlds where the Aeldari had chosen to live in a manner different to their kin. Many worlds burned under the assault of the Thousand Sons, who began to utilize spirit familiars to aid them in overcoming the powerful Aeldari magic. These familiars were conjured from the warp, and their presence terrified the primitive xenos. Magnus learned that the technology he sought was called Webway gates, and he found many of them on the Exodite worlds, though all were destroyed before he could reach them. It seemed as though fate itself was conspiring to keep them from their goal.

It was during one of these campaigns Magnus heard of his brothers waging war against the orks around Ullanor. While he considered coming to the aid of Horus, one of the few brothers he actually tolerated, the idea of aiding Mortarion was repugnant, and so he kept to his own devices. Mortarion and Magnus had never gotten along due to Mortarion's hatred of anything Warp-related, and Magnus's relationship with him was almost as bad as it was with Russ. Magnus waited until the conclusion of the campaign, taking part in the Grand Triumph afterward. The sight of Horus being crowned as Warmaster did not bother him very much, for he had never sought leadership in the way many other brothers had. However, more disturbing though was the Emperor's announcement that he was withdrawing from leading the Crusade. Magnus had been having premonitions about his father for months, though they were so vague as to be meaningless. After Ullanor, Magnus returned to his campaign against the Aeldari, having located a craftworld and preparing his forces to raid it. He knew it was located somewhere on the Eastern Fringes, as well as its name: Iyanden, the obscure knowledge having been torn from the mind of a captured Farseer.

The Thousand Sons moved to begin their search, immediately coming under attack by all manner of foe. Craftworld Aeldari were the most common, though there were a surprising amount of human forces that fought under the xenos' banner. Several times they fought through massive migrations of orks, no doubt redirected toward them by Aeldari trickery. Thus Magnus's hopes for a quick campaign were dashed as the months turned into years. As time passed, Magnus found himself drawn to psychic rituals of a different sort, gaining mastery over summoning larger versions of the tutelaries that aided his sons. These creatures of the Great Ocean took all manner of forms, both zoological and mythological, and Magnus discovered some were more easily controlled than others. Some were even disturbingly close to being sentient, whispering lies and half-truths in the minds of everyone nearby.

It was during this time Magnus found himself approached by the primarch of the First, Lion El'Jonson. Magnus had never known what to make of this brother, and felt uneasy by his quiet lingering stares, as though his brother could read into his soul. Magnus had of course attempted to peer into Lion's mind, but found some of the strongest mental defenses he had ever seen, his subtle tendrils lost in a dark forest without end. The Lion and Magnus spoke on many things, from scholarly pursuits to the state of the galaxy. His brother spoke of the need for the most powerful and wise to rule, a sentiment Magnus shared, and he found himself beginning to like this brother of his. The primarch of the First spoke of Horus as being too naïve and soft-hearted to maintain the Crusade, an opinion Magnus shared as a result of Ahriman's periodic reports he had been sending ever since he was chosen to represent the legion to the Warmaster's Legion Auxilia.

The Lion hinted that their father was setting him up to fail while he worked on something more important beneath the Palace. Magnus demanded to know more, and Lion said he would tell him once he himself knew. He departed after giving one final message, warning Magnus to guard his mind lest he end up like Lorgar and Konrad. Magnus recalled the aberrations around the heads of those brothers, but as he pondered, his meditations were interrupted. Within a few hours of his brother leaving the system, Magnus received a new guest: a delegation of Custodes bearing a message from the Emperor: he and his legion were being summoned to a world called Nikaea.

Magnus accepted the summons, though on the inside he was furious. The Thousand Sons had fought for two years, losing many good soldiers in the process, and only now was the campaign about to bear fruit. Nonetheless he could not disobey a direct order from the Emperor himself, and so he and his legion accepted the Custodes delegation into their ranks as they traveled to Nikaea. He had a sinking feeling he knew what this was about: the Librarius project.

The Librarius

Magnus had long been irked by the rejection of his legion due to the superstition of others, and so he worked to remedy this. Perhaps if his brothers understood the utility of accessing the Great Ocean, they would not be so quick to judge. Thus with the help of his brothers Lorgar and Sanguinius, the two brothers on the best terms with Magnus at the time, Magnus set up what he called the Librarius. Under this ambitious project, psykers of the Fifteenth Legion would travel to other legions to train others of their kind so that all the legions could utilize their natural gifts. When the Emperor himself did not reply to the Crimson King's missives, Magnus was emboldened, and put his plans into action. Within several years, the groundwork was laid. For the most part, the legions accepted the Librarius, and had an active corps of psykers operating in their campaigns. Even Leman Russ used psykers, though the hypocrite claimed they were not psykers at all. Thus by the time of Ullanor, Magnus had considered the project a success, though it seems the issue was not as done as he'd hoped.

The Fifteenth Legion arrived above the Frontier World of Nikaea. This was a world only recently discovered by Humanity despite its relatively close location to Terra, and was still in the process of being terraformed by the vast Martian machines which dotted its surface. Floating above the planet were the varied fleets of many legions: vast Gloriana battleships sat next to tiny Sword-class frigates, hundreds of ships of every description, a gathering rarely seen before. At the center of this vast armada was the sleek golden Bucephalus, the Emperor's own ship. Magnus was displeased to note the Hrafnkel, flagship of the Space Wolves, docked close by it. The fleet of Thousand Sons, nearly a hundred vessels, had taken only a short time to gather due to their smaller size compared to other legions, and they took their assigned place in orbit between the ships of the Fourteenth and the armada of the Sixteenth, a position relayed to them by several humorless Custodians. Magnus and his chosen sons embarked upon their transports, and made their way down to the planet's surface.

Once on the surface, they made their way to their quarters, where they were irritated to find yet more Custodes who insisted upon standing guard outside their rooms. Magnus demanded to speak to the Emperor, but was soundly ignored. He began to feel as though this was what the Lion had spoken of: was this to be a council, or a trial? The next day, Magnus and his sons took their assigned seats in the vast conclave halls, and from the conflicting architecture, he was amused to see that both Dorn and Perturabo had worked on this ugly mess of a room. While both superb architects, their mutual hatred led them to be totally incapable of working together, and so the fortress had clearly been patched over at the last minute to unify the disparate halves. Rising through the Enumerations, Magnus reached his mind back into the past, and was intrigued to find that teams of Salamanders had come back the night before to fix it up. He could sense that eight other brothers were nearby, and wondered which would speak first.

Magnus's musings were interrupted by the Emperor calling the Council to order. The Emperor droned on about the purpose and reasons for this meeting, and so Magnus quickly lost interest. He watched as his brothers took their turns speaking: first came the supportive words of Perturabo on the usefulness of the Librarius, and Magnus felt a surge of gratitude for his longtime friend. These positive feelings soon gave way to irritation as Rogal Dorn used his time to denounce the Warp as unreliable and to insult Perturabo. His tirade soon gave way to a shouting match until the Emperor ordered them both from the room. Next came supporting words from Sanguinius, only to be balanced by the bitter complaints of Mortarion. Magnus could see his brother staring at him the entire time he spoke his nonsense about witches and perils of the Warp. Thus the first day of the Council ended with a deadlock and no progress made.

As the second day began, Magnus was irritated that he had been pulled away from his work for this, though he made sure not to let others see his frustration. The Crimson King was surprised to see three of the primarchs in attendance, Horus, Lorgar, and Vulkan, yield their chance to speak, and the next few days were taken up by a cavalcade of inferior psykers, both mortals and Librarians from various legions. As the fifth day dawned, the Crimson King was growing increasingly bored and frustrated, and his negative feelings increased tenfold when he realized there was only one other primarch left, the brainless savage Leman Russ. Russ spoke for hours about 'maleficarum' and how any who used psychic powers were no better than witches. Magnus could hardly believe what he was hearing, but to his shock he saw many in the crowd nodding at Russ's words. His brother brought in a coven of his barbaric shamans dressed in furs and a cadre of women in power armor whose very presence made Magnus's head begin to ache. By the time they left, Magnus could barely think, and shaking his head, he realized it was his turn to speak.

The Crimson King took the stand, and began to present his side of things. As he spoke, he wove subtle glamour into his words, imbuing each phrase with hints of empathic and telepathic strata that would win others to his side. It would not work on the strong-minded, but it would go a long way toward convincing the mortal men and women from the Council of Terra who stood beside their betters. He spoke of all the good his Librarius had done, and how many worlds he had brought to unity with little to no bloodshed. With satisfaction, he began to wrap up his speech, preparing to step down, until he saw his father stand.

The pressure was immense. Magnus felt himself forcibly cast out of the Great Ocean, his voice becoming coarse and unrefined as his connection was severed by the same Golden Light which filled the room. Shielding his Third Eye from the blinding radiance, he beheld the face of an angry god.

+DID YOU THINK I WOULD NOT NOTICE YOUR TRICKERY, MAGNUS?+ His father's wrathful voice rang through his head, and when his name was spoken, he heard many other words, accusations, and threats, each spoken as one yet separate beside his own name. Fifteenth. Failure. Disappointment. Liar. Magnus. All these and more flashed through his mind. Magnus had long thought he had been narrowing the gap, growing closer to matching his father's power through the many years of the Crusade. Every trove of knowledge, every secret tome had been drained of information and added to Magnus's own power. But this golden avatar of wrath before him showed him that he wasn't even close.

+ I HAVE ALLOWED YOU ENTIRELY TOO MUCH FREEDOM. THE LIBRARIUS SHALL BE NO MORE, I WILL BROOK NO COMPROMISE ON THIS MATTER.+ His father's words snapped Magnus back to reality.

"You can't do this to me. Do you know how much I've sacrificed!?" Magnus shouted.

+I KNOW ALL TOO WELL WHAT YOU'VE DONE, MAGNUS. DO NOT THINK I HAVE BEEN BLIND TO THE PRACTICES OF YOUR SONS. YOUR LEGION SHALL BE DIVIDED, AND YOU WILL BE COMING BACK TO TERRA WITH ME.+ Magnus slumped back into his chair, his mind reeling even as his heart filled with hate.

Magnus barely listened to the rest of the Emperor's decrees. All his work, all the progress he had made during the Crusade, was it all for naught? Was this how Lorgar felt when he was humiliated? Magnus allowed himself to be led back to his room by the ever-silent Custodes, stopping only to tell Legion Master Ahriman to handle the details of the legion's separation. Magnus spent the next few days in his room, until he was led out once more by the Custodes, this time to the landing field which held the Emperor's golden transports which were to take him up into orbit. As the Bucephalus prepared to enter the Warp on its journey back to Terra, he looked down upon the ships of his fleet, and swore he would be reunited with them once more.

A Legion in Exile

As his father was marched away, First Captain Ahzek Ahriman felt the pressure of his new responsibilities immediately. For the past year he had been fighting alongside the Sons of Horus in the Legion Auxilia, and so he returned to the Warmaster, to ask him what was to become of the legion. Horus assured him that the Thousand Sons who were part of the Auxilia would stay with him, and he would divide the rest of the legion into groups to assist the other legions. Following Ahriman's advice, Horus split the Fifteenth Legion by fellowship. Unlike the more conventional groupings of chapters seen in most other legions, the Thousand Sons had always been divided into fellowships, each led by a Magister and comprising around five thousand Astartes. The Warmaster proved to be more merciful than the Emperor, and thankfully did not assign any groups to legions that actively hated psykers such as the World Eaters or Death Guard, instead assigning multiple contingents in legions friendlier to the Fifteenth. Thus the Thousand Sons ceased to operate on its own, relegated to supporting roles for seven other legions.

For the next ten or so years, the dispersed forces of the Thousand Sons fought in shame alongside their cousin legions. Some spent their time in garrison duties, such as those assigned to the Ultramarines, Word Bearers, or Salamanders. Others were used as disposable cannon fodder, especially the fellowships which fought alongside the Iron Warriors or Imperial Fists. The Fifteenth had long been feared and distrusted, and even with their psychic powers banned, this superstition remained. Two fellowships of Thousand Sons had been attached to the Legion Auxilia with the Sons of Horus, while the final two operated with the Dark Angels. Lion El'Jonson had been decidedly neutral toward the Fifteenth Legion throughout the Great Crusade, and had not taken a position on the Librarius. With these traits in mind, as well as remembering the heavy casualties the Dark Angels had taken only a few years before, the Warmaster assigned two fellowships to Lion, which allowed him to resume campaigning.

The commander of the fellowships assigned to the Dark Angels was Magnus's old tutor, Amon. The Lion was notoriously secretive, and so the Word Bearers chaplains assigned to watch over the Thousand Sons were kept separate from most of the legion, not allowed to join in most battles or kept to the side when they did. To Amon's surprise, the primarch did not care if they used their powers, and in fact encouraged them to do so. Lion ordered them to utilize their powers to aid the First in battle, in particular those of the Corvidae cult, those who were most specialized in using their gifts to see the twisting threads of fate and masters of precognition. The Lord of the Dark Angels told Amon that he and his brothers would be allowed to use their powers to assist the Dark Angels, but that if they were caught he would not help them. Thus a fourth of the Fifteenth Legion continued to use their powers in defiance of Nikaea.

Amon became very close with the Dark Angel librarian Zahariel El'Zurias. Zahariel was a powerful psyker, and had long held his primarch's trust since he saved him from an assassination attempt many years before. The two spoke often on the nature of the Great Ocean, and Zahariel showed Amon many facets of the Immaterium that even he had not known of. Amon learned the true nature of the Thousand Sons familiars, and spread this knowledge to the Thousand Sons under his command. Thus within several years, Amon had cast aside his devotion to Magnus and the Emperor, embracing a new patron, the Architect of Fate. The Word Bearer Chaplains were quietly dealt with, fed into the most dangerous combat zones to kill them by attrition, while their messages were prevented from ever leaving the ships. Amon and Zahariel devised a dark ritual for those who would not embrace Fate, binding the souls of Thousand Sons who would not turn their backs on the Emperor into the very walls of the ships, their screams blocking the Chaplains' communications. With their sorcerous minds unshackled, the Alpha Legion spies in their ranks were quickly found out and killed. When not campaigning, the Lion would spend his time relaying messages and orders from the Warmaster, and so Amon used these opportunities to meet with the other Magisters, corrupting them to the worship of Tzeentch. Within ten years, the Thousand Sons were unified in purpose, eagerly awaiting the chance to reveal their true allegiances and use their powers openly.

While his legion fell to their dark fate out among the stars, Magnus the Red was kept on Terra in a warded prison in a tower that soared high above the rest of the Imperial Palace. Though the dwelling was comfortable and spacious, the walls were covered in protective runes similar to those of the dreaded Black Ships, and his jailers were Sisters of Silence. Magnus learned these were the same women from Nikaea whose very presence was capable of blunting and severing his connection to the Great Ocean. The Emperor rarely visited him, and all Magnus knew was that his father was occupied below the Palace. Instead, Malcador the Sigillite visited him once a week, repeatedly trying to reason with him. Magnus had long distrusted the Regent, seeing him as a schemer with an irritating knack for seeing through deception. The two argued back and forth, for Magnus had many grievances, especially about his brothers. Magnus demanded to know why those like Konrad Curze were allowed to use their powers, but Malcador's replies and denials only infuriated him, and most visits ended with Malcador walking away. Thus months turned into years, and Magnus spent most of his time staring out the window, watching the Palace grow exponentially in grandeur and size at a rate matched only by his increasing hatred for the Emperor of Mankind.

By the start of the tenth year of his imprisonment, Magnus began to have dreams. Though his cell was warded, Magnus still possessed the physical prowess of a primarch, and spent a great deal of time chiseling a small hole into one of the walls. This miniscule gap allowed him to project a tiny fraction of his astral form out beyond, though not much. However, a door goes both ways, and so Magnus began to dream once more. His sleep was wracked with recurring nightmares: the most common was a skeletal figure with one eye, bound to a golden throne, psychic energies constantly leached from him to power some unseen device. Another concerned his sons, who fought on unseen battlefields, their numbers whittled away until barely a fraction remained, while in others the Flesh-Change returned, leaving them no more than mutants put down by other Astartes in the colors of the hateful Sixth Legion. Magnus himself was no more than a horrified onlooker, watching helplessly over and over until one night, in the depths of the darkest dream yet, another vision of the future, Magnus heard the voice of his brother the Lion once more, and suddenly the vision vanished. The Lion told him to awaken, that now was his chance to avert these visions. All he needed to do was enter the dungeons below the Palace.

Magnus heeded his brother's words, and rose from his cell. Raising a mighty fist, Magnus smashed a hole in the walls of his cell, and leapt from the tower that was his jail. The further he fell, the more his powers returned to him, finally away from the dampening wards, and Magnus landed safely kilometers below. Hidden in one of the Palace's many tunnels, Magnus reached out to the minds of his sons, dispersed in their garrisons. His sons were overjoyed to hear from their father for the first time in years, and relayed Ahriman's messages and updates on the state of the galaxy. Still shrouded in his psychic glamour which hid him from the sight of others, Magnus descended into the depths of the Palace, while across Terra the Thousand Sons made their move. The Word Bearers chaplains were swiftly executed, pinned to the ground while daggers opened their throats. Moving from their barracks toward the outer precincts of the sprawling Imperial Palace, they were tracked by the watchful Custodes, who observed them from a distance as they tried to determine what they were doing. Word of Magnus's disappearance gave rise to alarm, and the Custodes made their move, leaping from all sides to detain the gathered Thousand Sons and keep them pinned in place while the Sisters of Silence rushed toward the scene.

A skirmish ensued in the southern edges of the Palace, as the Thousand Sons began to murder Imperial dockworkers and soldiers in a desperate attempt to seize control of dozens of shuttle hangars that contained transports to ferry them away. Back in Interex space, First Captain Ahriman directed the efforts of the Thousand Sons attached to the Sons of Horus fleet from the council chambers of the Mournival Majoris, using his authority and gifts to weaken and confuse the responding Sons of Horus. When Horus had fallen at the hands of the Interex, Ahriman had used all manner of sophistry to steer the events toward a profitable end. Had the Mournival allowed Ahriman and his sorcerers to reach out to the Warmaster in the Warp, he would have been corrupted to become a servant of Chaos and a figurehead to lead the rebellion. With the failure of those attempts, Horus was now deemed to be all but impossible to turn against his father, and so the Lion's plans would proceed without him.

Magnus himself was oblivious to these battles raging as he descended hundreds of floors below ground. He could sense his father's presence on the eastern side of the Palace in the medical wing, along with, surprisingly, that of his brother Horus. Though he was curious as to what the Warmaster was doing on Terra, Magnus's desire to avert his nightmares was stronger. He passed miles of esoteric machinery and the oblivious Martian adepts manning their stations, using short range teleports to avoid patrols and to sneak past the massive Eternity Gate. Before him stood a massive pyramid, thousands of empty niches in the walls on every side centering on a Golden Throne, identical to the one in his visions. Far below it, at the base of the pyramid, was a gateway that Magnus recognized at once: a Webway gate, though one constructed from adamantium instead of wraithbone. Magnus realized the import of the Emperor's work at once: such a project would render psykers superfluous except as fuel sources or weapons. Magnus was filled with rage at the sight of this work. He raised his hand, sending coruscating arcs of energy smashing through the delicate machinery keeping the gateway open, though most were deflected by the same powerful wards which had kept him imprisoned for so long.

As the last of his energies died out, Magnus was irritated to see how little damage had been done. Clearly his father had anticipated possible sabotage, though from what source Magnus could not say. Kneeling down, Magnus projected his astral form into the Great Ocean once more, seeking the room he required. The journey was swift, for the Emperor's light suffused and calmed the Ocean around it.

The entity was even more developed than before, with two grinning mouths, one where its head should have been and the other above its waist. Two curling arms stretched above its shoulders, while two more rested upon its folded legs. The entity spoke.

"Son of the Anathema, I know why you have come." The two mouths spoke in unison, though Magnus could hear dozens of other voices and alternative interpretations lingering on the edge of his perception.

"I must avert these visions. Fate must be rewritten." Magnus replied.

"Very well. What will you give me for the power you require?" The mouths curled into a sickly smile.

"You misunderstand me. I'm tired of your bargains." Magnus seized the insubstantial creature with chains of thought, and pulled, draining its essence as he absorbed the power of the Warp. Despite clearly containing immense power, the thing gave little resistance. Instead of screaming or threatening as might be expected, the entity only gave a mocking laugh before vanishing entirely. Magnus found himself back in the Throne Room once more. He unleashed his rage, and the wards shattered under the energies he was projecting. The ground itself twisted and warped beneath him, and the Custodes who rushed in to confront the intruder burned in the fires of change. If Magnus must be a monster to save himself, then so be it.

As the last of the energy drained away and the psychic storm faded, Magnus could sense the instability of the Webway device, and knew he needed to leave. Rushing back through the Eternity Gate, Magnus abandoned stealth, utilizing his powers to cast down the Custodes who attacked him. To his surprise, the Emperor was not getting closer, still in the presence of Horus; far behind him, he could sense the presence of Malcador, who was desperately struggling to contain the damage Magnus had wrought. He rushed through corridor after corridor toward the landing pads and shuttle hangars which lay above him, and none of his father's lackeys could stand before him. As he neared the surface, he was confronted by his brother Vulkan, who demanded answers. Magnus had no time to waste, hearing the shouts of more Custodes attempting to surround him from behind, and he cast Vulkan into the wall. Though he continued running, Magnus was forced to stop yet again as Vulkan had teleported himself into his path once more. His patience gone, Magnus attacked, driving his brother back as the two demigods clashed. Magnus reached out through the Ocean, calling upon his sons for aid, and they responded, mighty Sekhmet terminators, resplendent in their red and white battle plate, teleporting into battle to clash with the golden Custodes. Amidst the confusion of battle all around him, Magnus was tackled by Vulkan, and he gave in to rage, throwing his brother backwards before lifting him into the air. He yanked Vulkan forward, and skewered him through the chest before throwing his body to the side. Magnus was distraught at the thought of killing his brother, but pushed his emotions to the side, venting his fury upon the hapless Custodes.

Slaughtering wave after wave of Custodian Guard, Magnus and his sons fought their way into a hangar, seizing a transport that would convey them to a Warp-capable ship lurking in low orbit. Magnus communed with his sons, calling upon foresight to dodge the many shots fired at them from the Palace below. The shuttle docked with a small strike cruiser lying in orbit, and Magnus gave the order to flee for Prospero. As the strike cruiser fled the confines of Terra, it unleashed a final parting gift, a flurry of shots aimed directly at the Halls of the Astronomican. Though the powerful void shields stopped most of the shots, one made it through, causing the beacon to flicker. All across the galaxy, ships veered off course, suddenly bereft of their lighthouse, while the raw energies of the Warp seeped in across countless systems, and the defenders of Terra found themselves fighting with hideous monsters. Though they were no doubt eventually put down, the distraction gave the Thousand Sons enough time to escape the system, entering the Warp on their way to Prospero.

Sergeant Arvida panted behind the walls of a barricade. When his captain had told him to come to the Palace, he had obeyed despite not knowing their objective. All around him, his brothers had opened fire upon the Emperor's guardians while he stood motionless, stunned that their love for their father surpassed their loyalty to the Emperor. Despite knowing no fear, Arvida ran, unwilling to commit the same treason, the same heresy as his brothers. Thus he remained within the Palace, even as he sensed his brothers and primarch leaving Terra.

Maybe he should have joined them, then he wouldn't be stuck here. He should have known the Custodes would follow, and now hours later he had been found and was trapped. Suddenly he heard a voice in his mind, a presence that seemed to be nearly as powerful as his own gene-sire's.

+Revuel Arvida of the Thousand Sons, your loyalty has not gone unnoticed. Come, there is work to be done.+ Arvida stepped out from beyond the barricade, and beheld Malcador the Sigillite, leaning on his staff and giving Arvida a knowing smile.

Heresy: Nikaea Ignored

Now free of the Emperor's stifling laws, the Fifteenth Legion gathered in strength around its homeworld, over forty thousand Astartes alongside several thousand more from the various legions who had abandoned the Legion Auxilia. Magnus knew his lone legion would not be able to stand up to any significant counter-attack by forces loyal to Terra, and so he communed with his brother Lion through the Warp. Lion promised to aid him in exchange for his support, and so the Fifteenth joined in the nascent rebellion. The sons of Magnus began to lay whispers in the Warp, stirring up rebellions across the galaxy in preparation for the coming war, while the Lord of the First himself used these distractions to gather his allies, and Magnus sent him the Astartes of the Legion Auxilia as a pledge of support. The Lord of the Dark Angels was ostensibly loyal, which meant he was able to go unnoticed, and thus the Lion was able to inform Magnus that the Space Wolves would be coming, giving him vital details as to where and when they would arrive. Thus prepared, Magnus laid false trails within the Warp to deceive the loyal astropaths, leading them from system to system as Warp-travel attrition took its toll.

By the time their Rune Priests had discovered the ruse, nearly a year had passed, by which time the Thousand Sons had ample time to prepare their trap. The Lion had given Magnus knowledge of a powerful ritual from the Age of Strife, and the time they gained allowed the Fifteenth time to perfect the ritual. When the Space Wolves arrived in the Prospero System, they immediately came under fire. They were relentlessly bombarded by unnaturally accurate shots from the ensorcelled guns of the Fifteenth Legion fleet, all working in perfect harmony. Magnus himself guided the efforts of his sons, his psychic might lending them focus, while his own ship, the Photep, was rendered invisible, easily dodging the stray shots sent its way.

Nevertheless, the loyalist armada bludgeoned its way through the outnumbered defenders of Prospero. Compared to the Fifteenth, the Space Wolves had always been a much larger legion, outnumbering the Thousand Sons nearly three to one in terms of Astartes. In addition, their ships were protected by the efforts of their Rune Priests, and Magnus was infuriated to see his brother brazenly violate the Edict of Nikaea. However, Magnus had accounted for this, and this initial battle served only to draw his brother's fleet into position. The Fifteenth Legion vessels broke into full retreat, relentlessly pursued by the Emperor's Executioners. The Space Wolves reached the desired location, precisely between Prospero itself and the sun which it orbited, and Magnus, assisted by his most powerful sons, activated his ritual. The gravitational forces of the two celestial bodies, both constantly pulling on each other, were imbued with the power of the Great Ocean, and began to act as an oversized Warp drive. A massive tear in reality opened up in the heart of the loyalist fleet, and within a minute, nearly a hundred ships had been dragged into the Warp.

As the rift sucked his brother's vessels in one by one, Magnus opened a line to the Hrafnkel, and Russ was quick to accept. Magnus openly laughed in his brother's face as the barbarian Russ howled insults and dire oaths of revenge. By the time the rift closed, swallowing his brother's flagship last of all, nearly two thirds of the Sixth Legion fleet had been cast to the Warp, where it would surely be dashed to pieces by the endless currents of the Great Ocean. The few Space Wolves vessels left beat a hasty retreat, jumping into the Warp which was now raging due to the massive bloodshed which had just occurred. Magnus had achieved total victory, and was now free to carry out his own plans. Lion was pleased by their success, and told Magnus he would send for him soon, but until then they were free to return to their own designs. Magnus fumed at his brother's arrogance in commanding him, but feigned deference, and in return received knowledge of the location of a functional Webway gate that had been captured by the Dark Angels during the Great Crusade.

The Thousand Sons traveled first to Nikaea, venting their fury upon the barren world in revenge as they wiped from existence the place of their humiliation. After leaving Nikaea, Magnus resumed his grand schemes which he had left off years earlier, leading his Sons into the labyrinthine depths of the Aeldari Webway network. His genius mind allowed his sons to make great headway through paths which would have left lesser mortals wandering for eternity, and his Sons slaughtered their way through the capering xenos which defended the ultimate prize: the Black Library. By psychically tearing information from the minds of hapless captives, Magnus realized control of the Webway was trivial compared to the knowledge he would gain from seizing control of the Library, and so directed two fellowships of his sons to seize it while he himself along with the rest of the legion traveled to Davin to stand by his brothers' side.

When Magnus returned from the Traitor's Triumph, he was infuriated to learn his sons had been driven back and utterly routed. The hapless Magister of the Third Fellowship, Hathor Maat, trembled as he relayed news of their defeat at the hands of the Alpha Legion. In rage, Magnus burned his son to ash with a psychic flame, promoting a legionary by the name of Aforgomon to become Magister of the Third Fellowship. The Fatewoven, as Aforgomon came to be known, became Magnus's closest advisor, a member of the Corvidae whose predictions rivaled even Magnus's own. Magnus and the Fatewoven attempted to track down Alpharius, for surely the Alpha Legion would be broken and unable to defend the Black Library if their primarch were to be killed. Meanwhile, the rest of the Thousand Sons joined the war effort, aiding the other traitors on the drive on Terra.

Years passed as the Heresy ground on. Magnus grew tired of his endless hunt, for the head of the Hydra proved impossible to track, no matter what dark incantations he tried. The Crimson King turned his attention back toward gaining power by other means, power enough to enter the Black Library as well as cast down both the Emperor and the Lion. His sons brought all manner of sorcerous lore back to Prospero, which Magnus used to amplify his own power as well as that of his Sons. In order to aid the war effort, the Crimson King cast a foul ritual, utilizing human sacrifice to create what became known as the Eyes of Magnus. These daemonic orbs were gifted to other traitor legions in order that Magnus might gain knowledge from all areas. Sometimes this was done openly as with the fleet of Sigismund, where the Eye of Magnus was used to scry Vulkan's defenses. Other times this was done in secret, such as the Eye attached to the Dark Angels fleet, where it spied upon the Lion before eventually being discovered and destroyed.

While his Eyes watched the galaxy, Magnus spent most of his time swimming in the depths of the Great Ocean, absorbing power and learning the secrets of the universe. His legion was left to its own devices, and a power struggle ensued as Ahriman and Aforgomon struggled for control of the legion, each seeking to gain the loyalty of the other fellowships. Many were their plots and schemes, each attempting to undermine the other through the use of treachery and ever-more spectacular displays of psychic mastery, but in the end, the Fatewoven proved the victor. By the time of the Battle of Verzagen, he had gained the allegiance of seven out of the nine fellowships, and led them to incredible success against the Space Wolves, who took heavy casualties against their sorcerous might. With Verzagen secure, the Lion's forces finally broke through Bastion Omega, clearing the way to Terra. Ahriman refused to obey Aforgomon, and so brought his forces to fight alongside the Primarch directly in hopes of winning his favor. Thus while most of the legion pressed ever closer to Terra alongside the rest of the traitors, Magnus, along with Ahriman and his two fellowships, moved eastward to the ruined planet of Khur. The once-shining Shrine World of the Word Bearers was now nothing but a dead world, sitting on the edge of the Ruinstorm which his brother Guilliman had created. Magnus had not spoken to his brother in years, though he had sensed the touch of the Great Ocean on his brother and learned of his ascension to become a being of the Warp. Yet Guilliman was far from his kingdom, gone to join the rest of the primarchs at Terra, and so Magnus landed upon Khur unopposed, and began to tap into the planet's leylines, converging on the ruins of some long-destroyed city.

As Magnus drained the planet of its power, the Thousand Sons with him set up defenses across the planet. Though loyalist assault was unlikely, the Ruinstorm itself was dangerous. The same hurricane winds that kept the loyalists inside Ultramar spat out hostile daemons who threw themselves at the guns of the Thousand Sons. The Fifteenth had long since embraced Chaos, recognizing their tutelary spirits as the daemons they truly were, though the Thousand Sons saw themselves as masters of Chaos, not the slaves to darkness that the other legions were. Thus they recognized these daemons as belonging to other choirs opposed to Magnus's work as the Master of Fate, and crushed them with ruthless efficiency. Meanwhile, Magnus drew in the energies of the Ruinstorm into himself, swelling in power even as he drained the storm of its potency.

These defenses were later put to good use with the arrival of the Seventeenth Legion, now free of the storm which had kept them penned in for so long. Magnus had foreseen Lorgar's arrival, and looked forward to killing his brother for turning his back on him at Nikaea. The Crimson King waited for his brother within the heart of his ritual circle, continuing his plans even as his sons died around him. In his place, Ahriman led the defenses, clashing with the forces of Argel Tal, finally coming face to face on the steps of the temple at the heart of the city. The Legion Master and the Zoa battled furiously, Ahriman's sorcery inexplicably washing off his foe's crimson armor. Argel Tal cast down his counterpart, uttering a litany to the God-Emperor as he mortally wounded Ahriman. The Legion Master was dragged away by his comrades as Argel Tal rushed into the temple to aid his primarch. The forces of the Thousand Sons were thrown into full retreat by the insane fury of the Word Bearers, and they began falling back to their dropships.

Although he was aware the battle had turned against his forces, Magnus stayed where he was, continuing to toy with Lorgar within the temple. Even with his sons in retreat, the Word Bearers would break with the death of their primarch, and Magnus prepared to kill his brother and absorb his essence. Even the intervention of Argel Tal proved incapable of stopping him, though for some reason it sent the Aurelian into a rage. Before Magnus's disbelieving eye, his brother glowed with the same horrifying golden light he had seen so many years before. He quickly grasped the situation, for Lorgar had somehow managed to tap into his innate psychic might, which now spilled out uncontrollably and severed the leylines. Magnus screamed with fury as his ritual was ruined, the powers he tried to grasp now beyond his reach. The Crimson King wasted no time trying to cross blades with the transfigured Lorgar: there was no point in remaining anymore. Magnus teleported up to his ship, and gave the order to return to Prospero.

Siege of Terra: Prospero Burns

The fleet of Magnus sailed swiftly through the Great Ocean, the raging tempests proving no obstacle to them. For months Magnus had siphoned power from the Ruinstorm, draining the lore of the universe then venting the excess energies into other realms of the Immaterium. These storms filled the galaxy, breaking through the fabric of reality and greatly increasing the frequency and potency of daemonic incursions. In addition, the storms harassed and slowed the movement of loyalist fleets, a powerful tool for the Lion's forces, and a convenient excuse for why the Crimson King had not accompanied his sons to Terra. While Magnus and his battered forces returned to Prospero, the rest of his legion fought alongside their traitor brethren, pushing Vulkan's defenses to the breaking point as they flooded into the Solar System. Their powerful sorceries were first put to the test in their conflict with the First Sphere forces around Neptune. The blue gas giant had been named after the ancient Romii god of the sea, associated with the concept of change and mutability, and the Sorcerers turned the echoes of those beliefs to their advantage. Daemons beyond count began to emerge from the cloud banks of the planet, from swarms of screamers that formed living shields for the Fifteenth Legion vessels, to massive behemoths that swallowed entire space stations and gas mining platforms. The Salamanders fought bravely, but were overwhelmed within days, falling back to their other defenses.

The Fifteenth Legion next moved on to assist their allies in the assault on Jupiter. While the dour sons of Perturabo clashed with the Sons of Horus defending the moons and the Jovian Shipyards, Magister Aforgomon and his cabal of sorcerers began a hideous ritual within the atmosphere of Jupiter itself. Humanity had long theorized Jupiter was a failed star, a rival to the glory of Sol, and so it was a natural choice for their foul designs. Using the endlessly-churning Great Red Spot as a focal point, the sorcerers tapped into its Warp-resonance as a source of mutability and change, creating a gaping chasm in the skein of reality in the shape of a horrific great eye, the pupil of which spewed forth the remaining traitor legions who had waited in the Warp for the gateway to open. Tens of thousands of new ships spilled out in wave after wave at a rate which would have been impossible at regular Mandeville points or the Elysian and Khthonic Gates. The Sons of Horus were forced into full retreat, fleeing both from the new traitor armada, as well as the gateway itself. Its inhabitants disgorged, the Eye began to shift into a swirling kaleidoscope of impossible colors, a twisted mirror of the Astronomican. Unholy energies began to seep out from this dark beacon, polluting the aetheric currents around the Solar System as it called the inhabitants of the Warp toward Terra.

After allowing their traitor brethren to clear the way through the remaining loyalist defenses above Terra itself, the Sons of Magnus landed in force around the many hives of Europa. There they sought the primeval knowledge of Old Earth contained in these ancient hive cities, clashing with the Salamanders and Alpha Legion who defended the arcologies. The Thousand Sons were ruthless in battle, slaughtering any civilians in their way as they tore through defenses with sorcerous might, but they did not inflict the same debaucheries as their cousins in other traitor legions did. The sorcerers of the legion remained much as they were during the Great Crusade: isolated, taciturn, and entering battle only when it pleased them. Thus for most of the Siege, they remained an object of mystery and worry for the loyalists, for none knew when and where they might finally strike.

While the sorcerous elite remained withdrawn, ransacking repositories in search of their own selfish designs, the less psychically-gifted joined the battle alongside the forces of the Iron Warriors, most especially those who were part of the Order of Ruin. The Arcana Astartes of this brotherhood were known for their organizational acumen and knowledge of the underlying structures of the universe, and so they got along well with the siege-masters of the Fourth. Their sorcerous acumen lent incredible accuracy to Perturabo's siege engines, and were instrumental in the grand push against the Colossi Gate after the fall of the Raven's Gate spaceport. However, their aid soon caught the attention of others. Alpha Legion kill-teams operating out of the ruins sprang upon many Thousand Sons forces, turning the bombed-out ruins of the Outer Palace into a massive zone mortalis. In addition, the sorcerers of the Order of Ruin soon learned that associating with the Iron Warriors came with a cost. Friendly fire incidents had been seen as unavoidable in this type of warfare, but the Seventh Legion's rivalry with the Fourth meant that these incidents were quite frequent. Bombing raids and 'poorly-aimed' artillery strikes were frequent, and many Thousand Sons became victims of friendly fire, caught between the rivalry of those who should have been allies. Nonetheless, enough survived to take part in the climax of the Siege, and the Thousand Sons joined their allies in the final pushes into the Inner Palace, joined at last by the sorcerous elite of their legion who had come to claim the Emperor's forbidden lore kept within the inner sanctums.

While his sons fought on Terra, Magnus arrived back on Prospero, locking himself within the grand pyramid of Tizca to meditate on how Lorgar had managed to defeat him. His Third Eye had been weakened, blinded by his brother's golden light, and he found himself unable to peer into the future as he once had. Sealed within his chambers and all outside contact cut-off, Magnus turned his attention inward while his sons tried to recover from the casualties the Word Bearers had inflicted upon them. They were thus unprepared for the return of a foe they had long thought destroyed: the Rout of Leman Russ. Sent into the Warp years before, Magnus was certain his brother had been trapped forever and his legion destroyed. The Wolves still fought the Thousand Sons during the Heresy, such as at Verzagen, but never in any great number, and the Fifteenth Legion was long since satisfied that Nikaea had been avenged. But it seemed the Wolves had not forgotten, and had come to claim their revenge.

Thousands of Sixth Legion Astartes, along with a force of Aeldari, landed upon Prospero after breaking the meager fleet in orbit then bombarding the cities below. If the full might of the Thousand Sons had been there, the Sixth Legion would not have stood a chance. However, only two fellowships had accompanied Magnus to Khur, and barely half that number survived the assault of the Word Bearers. Thus less than five thousand Arcana Astartes stood to oppose the foe, and while they reaped a great toll with their powerful sorceries, the enemy was simply too much, and Prospero Burned. Magnus was shocked to learn who dared to assault his world, and infuriated by the loss of so many precious repositories of knowledge. Yet before Magnus could join the battle himself, he was assaulted within his own sanctum. Throughout the Heresy, his Sons had uprooted Aeldari artifacts and brought them back to Prospero for experimentation, though none were ever successful. The lower chambers of the pyramid were filled with these structures of various sizes, and the largest Webway gate, long dormant in the lowest chambers of the pyramid, flared to life, and out stepped Leman Russ.

His brother had changed since Magnus had last seen him. Gone was the boisterous savage bedecked in pelts, who howled like a madman when entering battle with an axe in one hand and a sword in the other. In his place before the Crimson King stood a silent, grim figure who could be best described as an executioner. His blond hair had turned the gray of winter, deep scar lines criss-crossed his face, and the brown straps of an eyepatch covered what used to be his left eye, an ironic mirror of Magnus's own. In his hand stood a great golden spear, which shimmered with the same anathematic energies as Lorgar had back on Khur.

Russ wasted no time trying to speak with his brother, and nor did Magnus. The time for talk had passed: there was only battle now, all thought of brotherhood forgotten in the face of such enduring rivalry between these bitterest of foes. The Lord of Winter and War was in the Crimson King's face before he could utilize any psychic powers, and the two demigods fought at speeds no mortal could match. Though larger than his brother, Magnus had never been able to match Russ for strength or prowess, and so he began to take wounds, his armor rent and shattered. That is not to say Magnus did not give a good accounting back: his bronze axe, the replacement for the blade with which he had slew Vulkan, hacked into Russ, piercing his breastplate before a fist wreathed in psychic flame slammed into the wound, driving shards of ceramite into Russ's heart. Even as Magnus landed this mortal wound, he realized his error. This was no mistake: Russ had left this opening, this trap.

The golden spear-tip flicked upward, and only the fortunes of battle saved Magnus from being impaled through the heart. The Crimson King twisted at the last moment, the blade nicking his skin to leave the slightest of cuts, but it was enough. Truth became manifest as the golden light illuminated Magnus's confused mind. In a flash he realized the nature of the bargains he had been making. He realized the import of centuries of meddling beyond his ken. And even as this Revelation flashed through his mind, Magnus felt himself lifted up. Too late, his mind and attention returned to the present, as the Wolf King brought his brother down upon his knee, shattering his spine.

Even as Magnus writhed in agony on the floor with Russ standing above him preparing to deal the final blow, time seemed to slow down as the Crimson King's mind was assaulted by visions. The entity from which he had received and taken power revealed itself to him as the Changeling, Herald of Tzeentch. Speaking for its master, the Changeling revealed everything had transpired according to the will of the Architect of Fate. The psychneuein, the flesh-change, the battles of the Great Crusade, all had unfolded as Tzeentch foresaw, Magnus a mere puppet the entire time. As the Crimson King feebly protested that he was the master of his own fate, the daemon revealed Tzeentch had given him the power and had now taken it away. Russ's spear only revealed the truth: Magnus watched helplessly as his sons were now in full retreat from Terra, sensing the fall of their father. The Crimson King reeled in horror, and Magnus's mind shattered, and he begged the entity to take away this awful knowledge, to save him and his Sons.

The hooded daemon seemed as though it were grinning at these words, and its four hands snapped in unison. Prospero faded away, and Magnus found himself in the Warp. When Russ's spear came down, it pierced only shadows and mist before striking the floor beneath where his brother once lay. Russ howled in fury, for he knew his brother had escaped. The few Thousand Sons upon Prospero disappeared in the same instant as their father, plucked from the midst of battle and cast into the Warp to what came to be known as the Planet of the Sorcerers. They had not waited long before they were joined by the remnants of the legion that had gone to Terra, though Magnus himself was nowhere to be seen. After departing the Solar System and entering the Warp, the fleet had found they were drawn to this world, and no matter what direction they jumped, they found themselves drawing closer. Eventually they gave up, and set course for the world Fate had in store for them.

Post-Heresy: Masters and Puppets

As the Fifteenth Legion gathered around the remaining Magisters, arguments broke out. Brother turned against brother, recriminations and accusations hurled over why they had been forced to retreat in the first place. At the climax of the argument, just as it seemed the legion was going to commit fratricide, their discussion was cut short by the arrival of Magister Aforgomon, who smote the ground with his staff. As the echoes faded, Aforgomon collapsed to the ground, aetheric energies coursing from the vents in his helmet as his body slumped like a puppet whose strings were cut. The crackling vapors began to coalesce, joining to form the shape of a two-headed avian monstrosity. The daemon that was once Aforgomon Fatewoven spoke, revealing its true nature as Kairos, the Vizier of Tzeentch.

Barely ten thousand had survived Terra and Prospero, and as Kairos waved its taloned hands, the legionaries felt the protective wards of Magnus fade. Exposed to the mutagenic energies of the Warp, the flesh-change returned with a vengeance, and the Astartes began twisting into hideous beasts. Only the sorcerers of the legion seemed unaffected by the Change, their wills forcing away the curse if not the terrible agony that accompanied it. The afflicted legionaries pleaded with the daemon to save them, begging and promising anything to be rid of this pain, and so the sons of Magnus swore eternal servitude to the Architect of Fate. The twin-headed daemon smiled, a horrifying sight, and the affliction ceased, though barely a thousand true Space Marines remained to recognize it, each one now a sorcerer of unparalleled might. The rest were now mindless beasts, driven by the will of Tzeentch and obedient only to the commands of their sorcerous masters. A ripple of color washed across the gathered crowd as the Thousand Sons' armor shifted from crimson to blue, ringed with bands of bronze that symbolized their eternal slavery to the Changer of Ways.

Deep within the Crystal Labyrinth, the Crimson King watched helplessly as his sons gave away their freedom, and he too began to feel the touch of Tzeentch. His body was warped and mutated, with what little of his humanity still remaining cast away as he became a Daemon Primarch. The metallic wings decorating his armor twisted and extended, becoming flesh and feathers that shifted in a prismatic blur, while his skin, once a coppery, reddish-brown color, now shifted to a crimson hue unlike any human. His powerful mind, once his pride and that which he valued most, was shackled by ninety-nine chains of servitude, both punishment and reward from his patron. Only the smallest shard of sanity remained, occasionally surfacing before being driven away to be filled with conflicting desires, each thought a facet of a plan in the endless schemes of Tzeentch. Elsewhere in the Warp, the choirs of the other gods of Chaos felt the ascension of this new foe, and the Crystal Labyrinth of Tzeentch came under attack by foes seeking to prevent the ascendancy of the Architect of Fate. Likewise, the domains of the other gods were assaulted in turn as the Forces of Fate struck back in equal measure. The Great Game remained the same as it always had, the new players taking their place alongside the old as the Architect of Fate continued to laugh over them all.

Despite their service to the god of lies, the Thousand Sons name has become the one truth of their legion. Across the Material and Immaterial realms, barely a thousand true Arcana Astartes remain, and even they feel the mutagenic touch of their patron. This number has remained constant throughout the centuries, for Tzeentch keeps a close eye on his favored. Each is a powerful sorcerer who acts to fulfill multifaceted schemes and stratagems that play out across centuries. However, one plan unites them like no other: gaining entrance to the Black Library. Such a treasure trove of information would no doubt hold the key to freeing themselves from the clutches of Tzeentch. The Changer of Ways smiles upon their efforts, for such hope and planning serves him regardless of whether or not they succeed. Such schemes generally involve bloodshed, and so the sorcerers send forth their mutated brethren, the Shogaal, to do their bidding.

The Shogaal are the antithesis of the cunning sorcerers. Also known as the Mutalith, these animalistic abominations embody the ephemeral power of Tzeentch with their varied appearances. However, their hides most often come in shades of red, a mockery of the armor they once wore in service of the Emperor, and so they also bear the appellation of 'Rubrics'. Many exhibit the bestial appearance of jackals and other lupine aspects, each one a foul reference to their eternal foes the Space Wolves. They are driven by a savage animal cunning and are ruthless in battle. Magnus himself occasionally enters into conflict alongside the loping packs of his sons, just as insane as his debased children. The Crimson King has become incapable of any plans of his own, utterly insane and driven solely by the will of Tzeentch. To face him is to gaze into madness itself, and few mortal foes can stand before him before they too are mutated beyond recognition. In his place, the Fifteenth is led by the Coven, a council of the most powerful sorcerers in the legion who each strive to bring their ruinous schemes to fruition while sabotaging the plans of both friend and foe. The very presence of the Thousand Sons upon the battlefield is enough to drive their foes mad with paranoia and worry, turning upon each other for fear their allies are part of some nefarious scheme. Many battles have been won in such a manner before they have even begun, for even the suspicion of treachery is a potent tool as effective as any real betrayal.

Homeworld, Recruitment, and Geneseed

Recruitment has never been easy for the Fifteenth Legion, even before pledging themselves to the Great Mutator. The gene-seed of Magnus has always performed better when implanted in those with psychic potential, with both a better chance of acceptance as well as less chance of activating the curse of the flesh-change. The sorcerers of the Legion have long since realized that their father's bargain had been made with the Father of Lies, and have resigned themselves to the effects of the curse, though many still hope to cure it. One such mind is the former legion master, Ahzek Ahriman.

Ahriman

Once master of the legion, the being known as Ahzek Ahriman has fallen far since then. After losing control of most of the legion fellowships due to the machinations of the daemon Kairos Fateweaver, Ahriman fell in battle on Khur at the hands of Argel Tal. His loyal companions rushed him back to a ship, but the damage was too great, and he had to be implanted within an Osirian dreadnought sarcophagus to survive. Thus he was unconscious as the daemons of Tzeentch claimed his brothers for their own, though his warded shell protected him from their foul influence.

Before his entombment, he was Magister Templi of the Corvidae Cult, the most accurate precognitive his legion had ever seen. However, the constant pain he was subjected to as a dreadnought had left this ability neutered, unable to concentrate on divining the future as he once had. Ahriman nearly gave into despair when he learned of his inability to see the future or cast ritual spells of any variety. Yet the legion's new patron was, among other things, the god of hope, and so Ahriman clung to the hope that one day he may be free of this prison, just as he hopes his brothers may yet be freed from the clutches of Tzeentch. However, it is clear to all that his brothers do not see things the way Ahriman does: they revel in the incredible psychic mastery granted to them by worship of the Architect of Fate, and many pity Ahriman for his incredible self-delusion.

Despite this, Ahriman is still a force to be reckoned with. His dreadnought body allows him to take extreme amounts of punishment, and he has mastered the lore of biomancy in order to strengthen his mortal shell even further. Ahriman spends most of his time divining the will of Tzeentch at his primarch's side, interpreting the mad words of his father in ways only he understands. On rare occasions, he journeys into realspace to enact the final stage of his plan that stretches back millennia, bringing woe on an unparalleled scale with every intervention. When forced to enter combat, he is a living battering ram, and his sorcerous might, even thus limited, is still more than a match for most foes.

Like most traitor legions, the Thousand Sons do their recruiting both on inhabitants of the Eye of Terror, as well as hapless boys captured from realspace raids into the Imperium. As servants of the Architect of Fate, they are no strangers to playing the long game, manipulating the fates of entire worlds in order to yield powerful minds worthy of receiving the geneseed. Such planning inevitably takes a great deal of time to bear fruit, during which it is subject to disruption, at the hands of foes, allies, or even random fate. Thus the legion has remained at roughly the same size as it was at the end of the Heresy: nine hundred and ninety nine sorcerers, and Magnus himself makes one thousand.

Their former homeworld, Prospero, was destroyed at the end of the Heresy. When legion sorcerers searched for it in the skeins of fate, they discovered that Leman Russ, Primarch of the Space Wolves, had ordered the planet's destruction after Tzeentch plucked the legion from its fate. The new world they found themselves on was no paradise, a world deep within the Eye of Terror which came to be known as the Planet of the Sorcerers, or Sortiarius in the language of Old Prospero. Whether this world was natural or the by-product of some forgotten scheme, Sortiarius is a world bathed by the Great Ocean, even by the standards of other daemon worlds. Sworn solely to the Architect of Fate, the world is lit by nine false suns and wracked by mutating energies: entire continents shifting on a daily basis, for time has no meaning here. The ground is rocky and dead, the skies constantly split by aetheric lightning, while the seas themselves are composed of the moaning souls of the restless dead, all victims of various schemes and plots. Around the planet stands a shifting white ring which blocks the burning light of the Astronomican, the pure light of truth that has no place on a world of lies. Like the seas, the ring itself is composed of souls, and these are the souls of liars, eternally condemned to recognize their sins underneath the harsh light of the Emperor's judgment. In the rocky wilderness, flocks of Tzaangor roam: hideous bird-headed mutants that fight each other for both scraps of knowledge as well as the chance to cannibalize their fallen brethren for sustenance.

Like Old Prospero, Sortiarius is a library world. The Thousand Sons have created cities of bone and glass in imitation of their lost homeworld, every wall inscribed with sorcerous runes to keep the shifting madness at bay. Within these structures lies the accumulated lore of ten thousand years, though nothing as mundane as actual books. Vast pools of murky liquid dot the cities, each a collection of memories and information gleaned from the Sorcerers who ply the galaxy while they further their own schemes. In these pools lie the bulk of the legion's knowledge, and many Thousand Sons choose to 'bathe' in them, seeking forgotten knowledge as they relax, listening to the winds of the Warp whisper to them as they sweep past. For more guarded knowledge, tomes do exist, daemonic books written in blood on paper made from flayed skin.

Dotted about the constantly changing world lie vast structures known as Flux Cairns. These daemonic prisons are one of the few locations not subject to the Winds of Change, and for good reason. Contained with their walls made from solidified Warp crystal lie both daemons and mortals, both prisoners and fuel sources. Their power and knowledge is constantly drained to feed the vast mana forges which fuel the industry of the Fifteenth Legion. These Cairns exist in both the Material and Immaterial Planes, and powerful Sorcerers can summon them to bind unlucky foes within, who are often driven mad by having their minds torn between two planes of existence.

At the center of Sortiarius lies Tizca. The original city was reduced to dust under the guns of the Sixth Legion, but its place in the hearts of all Thousand Sons created an echo in the Warp, one which brought more substantial reality in the shifting tides of the Great Ocean. Tizca contains one of the greatest known repositories of lore in the galaxy, and all Sorcerers must come here when returning from their campaigns, to pay a tithe of knowledge to the Council of Magisters. Also known as the Rehati, the Council consists of the Nine Most Powerful Sorcerers, each of whom has taken command of their fellowship by blade and scheme. On the outskirts lay vast holding pens, where sorcerous chains bind the bestial Shogaal until such time as they are needed. The tower of the Cyclops sits at the middle: an impossibly vast nine-sided tower, within lies the chained body of the Mad Primarch. Bound by chains of Iron Warrior construction, Magnus has been imprisoned here for centuries, millennia, or perhaps eternity, it is impossible to say. The Council of Magisters treated with the forges of their cousin legion, and in exchange for some dark payment, received chains capable of binding a daemon primarch. These chains force stability onto the being of pure change their father has become, and are only loosened when the Council wishes to unleash their father onto some battlefield. Even when the Mad Cyclops falls, his essence is forced to return to the tower, the metaphysical chains binding him to this place. The Council knows their father could break the chains if he were lucid, but Magnus has become the embodiment of the insanity of Tzeentch, and is unlikely to recover any time soon.

The gene-seed of the Thousand Sons is wracked by change and mutation, a flaw present even before it was exacerbated by pledging their service to the Architect of Fate. It is a matter of random chance as to which organs do and don't work, and all who receive it are touched by the random mutations that come as a part of serving Chaos. Those implanted with it will inevitably succumb to the flesh-change if they do not possess enough psychic aptitude to quell the raw energies latent within. Those that do master this flaw find their powers boosted nine-fold, becoming an incredibly powerful psyker. These new sorcerers go on to become apprentices to more experienced members of the legion, generally in small groups of up to eight apprentices and one master. As they mature, they master the various esoteric lore of the legion, specializing in a particular cult and mastering their own pack of Shogaal to serve them. Eventually most legionaries go on to challenge their former master, scheming to kill and overthrow him and take his place. Such schemes are expected and approved by their masters, though any failed attempts are ruthlessly punished.

Combat Doctrines and Organization

Unlike many other Traitor Legions, the Thousand Sons fight much as they did during the Great Crusade. The legion has retained its unity and structure, divided into nine fellowships. Each fellowship is led by a powerful sorcerer, the Magister, each a master of battle magic and architect of myriad schemes. The Magisters have an unspoken pact amongst each other that they will not openly war with each other, instead relying on more backhanded methods when conflict arises. The Nine each possess their own tower, forming a ring around the Tower of the Cyclops. They generally operate individually, though they are more than capable of acting in concert when the need arises.

The Thousand Sons are incredibly hierarchical. At the top sits the Magus, a position always filled by their primarch, though he has not exercised true command since his ascension. Below him are the Nine, the Magisters who lead their fellowships and truly rule the legion. Each Magister of the Rehati commands a number of Sorcerers, the number fluctuating depending on recruitment and casualties. In turn, each Sorcerer commands a pack of Shogaal, their debased and monstrous lesser kin who are kept in holding pens until the time for battle comes. Scholars of the legion have long posited a being higher than the Magus known as the Ipissimus, though it is a matter of contention who such a being would be. Some say it would be the Emperor, their original creator, while others claim the title belongs to their patron Tzeentch.

Both separate and joined to the fellowships are the Nine Cults. Each Cult specializes in a particular lore of magic and sorcery. The Fifteenth Legion originally only had five schools of magic, but after the Heresy, these were replaced by new groupings. Every Sorcerer is a member of one of these Cults, though they do not correspond neatly to the Nine Fellowships, and each Fellowship is composed of all Cults. Some cults, such as the Cult of Prophecy, are evolutions of the previous Cults like the Corvidae. Others, like the Cult of Mutation, are entirely new, and are composed of those who have embraced the novelty and change brought about by their patron.

As a result of their focus on planning and scheming, the Thousand Sons do not enter battle as much as their cousin legions. They prefer to operate from the shadows, pulling the strings of unwitting puppets who believe their actions to be their own. Such schemes are almost always overly elaborate, for their patron rewards them for such complexity. However, such showmanship can lead their plans to be noticed before completion. Many plans are simply not important enough for the puppeteers to intervene, but those that interfere with plans deemed vital will draw the wrath of angry Astartes down upon them. The Thousand Sons are no less deadly for their reluctance to openly enter battle, and when they do, few are the foes that can stand against them. Their powerful magic makes a mockery of the laws of physics, as unearthly energies obliterate any trace of their foes or mutate them beyond recognition. Time itself reverses to return fallen Thousand Sons from the ground back into battle, or speeds up to render Sorcerers impossibly quick. The howling packs of Shogaal are just as deadly, their razor-sharp claws tearing through armor like paper, while their ensorcelled hides take damage far in excess than they have any right to.

The Thousand Sons have always focused on quality over quantity, and they are generally outnumbered in every conflict they enter. To rectify this, most battles begin with the summoning of tides of daemons. Bestial Tzaangors fight with primitive weapons while they act as shepherds for the Shogaal, while Flamers burn their foes to ash. Maniacal Horrors swarm their foes, splitting into two as they fall, their numbers seemingly without end. The most powerful of Tzeentch's daemons are the Lords of Change, bird-headed sorcerers whose abilities rival the most powerful of the Thousand Sons. On rare occasions, Magnus himself is summoned to wage war, utilized as an unstoppable storm that only dissipates when the foe has been vanquished, after which he is imprisoned once more by his own sons.

To face the Thousand Sons is to face the daemons of Tzeentch, for the Architect of Fate protects his favorite toys. The Thousand Sons rarely march to battle without such allies, but there is one daemon with which they will never align: Kairos Fateweaver. The Sorcerers of the Fifteenth Legion have not forgotten the role this particular daemon had in their downfall, and will even ally with forces of rival Chaos powers if it means stopping the schemes of the Vizier of Tzeentch. Thus Kairos has not been seen in the Imperium for many thousands of years, though the Inquisition remains vigilant.

The Thousand Sons believe that knowledge is power, and to know they act in fulfillment of Tzeentch's providence provides them with both advantage and assurance. They are utterly convinced that their Patron has great plans in store for them, and that they and only they are important and knowledgeable enough to matter in their master's plans. Each Sorcerer recognizes that many plans within plans had to come to fruition in order for them to be where they are now, and thus recognize that their patron has a vested interest in their survival. No additional Sorcerer may join the ranks of the Learned until a vacancy opens up, and their many deals with daemonic forces ensure they almost never die. Yet such thinking is hubris, for the galaxy is a deadly place, and sometimes the scales of Fate determine defeat and death of one or even many Thousand Sons to be more useful than their continued survival.

Thus even victory is made sour for those that face the Fifteenth Legion. Even when the Thousand Sons and their allies are defeated, one can never be sure this was not part of a greater scheme. The Grey Knights of Titan maintain occult information about foes within the Liber Daemonica, recording the True Names of daemons they encounter as well as other dangerous knowledge collected by the Ordo Malleus. Many pages are dedicated to attempting to unravel the manifold schemes of the Thousand Sons and their daemonic allies.

Azrik the Maze Keeper

By their very nature, daemons are near impossible to get rid of. It takes prodigious power to bring a daemon from the Warp into the Materium, for it takes a great deal of energy to manifest aetheric influence, be it corruptive energy or daemonic whispers. Thus daemons look to get returns for their investment, generally through powerful emotions such as those created from suffering and sacrifice. Daemonic rituals involving sacrifice yield exponential as opposed to linear returns, and the chaos gods themselves desire the emotions brought on by these rituals as a source of food.

Thus the daemons of Tzeentch plot and scheme, for by their actions they feed the master of which they are but an infinitesimal part. One such daemon of Tzeentch is known as Azrik the Maze Keeper. Intelligent even compared to other Lords of Change, Azrik masterminded the downfall of Warmaster Solar Macharius out in the Halo Zone in the far western reaches of Segmentum Pacificus. By whispering half-truths and lies through the mouth of a possessed advisor, the Warmaster became a puppet of the Maze Keeper, and his generals and their forces were turned against the Imperium. Only through the intervention of the Grey Knights was Macharius stopped, and after his defeat, the mortal host of Azrik was cast back into the Warp, banished for nine hundred and ninety-nine years.

Since his banishment in the early years of M41, the Prognosticars of Titan have determined Azrik is working on yet another wicked plot to circumvent his banishment through means unknown. All that is certain is that the Lord of Change has aligned himself with the Thousand Sons. The Grey Knights believe his return to realspace grows close, and have kept a close watch, ready for the Thousand Sons wherever they may emerge.

Little is more valuable in the Great Ocean than a starship, for such ships are the safest way to transit the endless tides. However, the fleet of the Thousand Sons is much different than those of other traitor or renegade forces. The flagship of the Thousand Sons, the Photep, was lost along with the rest of the Thousand Sons fleet during the Battle of Prospero, and few Great-Crusade or Heresy-era vessels survived the Scouring to flee into the Eye of Terror. In their place, the fleets are made of and led by Silver Towers, conical ships powered by sorcery that are controlled by powerful psykers. These Towers are incredibly quick, and act as loci to send devastating waves of aetheric energy to destroy any foes unlucky enough to face them. When retreating from battle, they drop powerful psionic mines which wreck any foolish enough to pursue too closely. The flagship of their fleet is a vessel known as Tizca's Revenge, a vast pyramid which is capable of keeping their mad primarch bound within until the Sorcerers deem it time to unleash their father unto the battlefield. However, due to his unstable nature, even compared to other daemons, Magnus cannot exist within realspace for more than a day every thousand years. The Council thus keeps him imprisoned for most of the time, occasionally releasing him to fight battles within the Eye of Terror, where reality is more fluid. If his Sons ever did manage to find a method to keep their father present for longer in the Material Plane, the consequences would surely be catastrophic.

All Thousand Sons possess a tutelary, a minor daemon bound to them when they become Astartes. These daemons constantly shift and change, absorbing excess energies to prevent the sorcerers from suffering any perils from the spells they cast. In times of need they can also act to absorb the effects of hostile psychic powers, and it takes great potency to overwhelm these spirits. However, when this does occur, the energies rebound back into the sorcerer, filling them with incredible amounts of energy. Usually this results in them being mutated beyond recognition into a spawn of chaos, but occasionally the sorcerer is capable of mastering these energies and turning them to their advantage. Such feats are rare, yet each has resulted in the Sorcerer ascending to become a daemon prince, who can now fulfill his schemes without fear of permanent death, though at the cost of eternal slavery.

The friends and foes of the Fifteenth Legion are marked with irony. Those primarchs Magnus once counted as friends such as Sanguinius and Fulgrim have become his most bitter rivals, fallen to rival Chaos powers. The Blood Angels despise the sorcerous ways of the Thousand Sons, while the message of despair and acceptance of the Emperor's Children is directly antithetical to the hope and change of Tzeentch. The Ultramarines are too self-absorbed to make reliable allies, while the Dark Angels are too untrustworthy. The warbands of the White Scars and War Hounds act as allies of convenience, though such partnerships never last long. The Thousand Sons have little dealings with the Crimson Fists, and poor relations with the Black Templars. Sigismund the Destroyer has long looked down on those who give themselves too deeply to the Warp, and thus scorns the sons of Magnus for what he sees as weakness. Nonetheless, some Sorcerers have chosen to abandon the Fellowships to join the Black Templars, usually in order to further their own designs or after a plot has gone catastrophically wrong. Of all the traitor legions, the Iron Warriors are the closest to being considered allies, though the intrinsically divided nature of Chaos keeps them from being true allies as they were during the Great Crusade and Heresy.

The most bitter foes of the Thousand Sons are the Space Wolves. The rivalry between the Sixth and Fifteenth Legions has remained strong through ten thousand years, and needs no explanation. Both sides have endless grievances, and will only ever end with the complete destruction of one or the other. With this in mind, Fenris itself, homeworld of the Space Wolves, has come under assault from the Thousand Sons multiple times. Each assault has done catastrophic damage to the death world they call home, while Sortiarius itself remains untouched due to its position deep within the Eye of Terror. The first and greatest assault was during M32, known as the Battle of the Fang. While most of the Sixth Legion was out on campaign against the Waaagh! of the Beast, the Thousand Sons struck, unleashing their mad primarch upon Fenris itself. Magnus and his Sons rampaged across Fenris, killing millions until Magnus himself was banished back to the Warp, obliterated from orbit by the Space Wolves who were forced to fire upon their own planet to halt his destruction. The most recent assault came during Sigismund's 12th Black Crusade. While the Templars struck at the Gothic Sector, the Thousand Sons used this distraction to assault Fenris again, inflicting great damage upon their stores of gene-seed before retreating back into the Eye once more.

Almost as bitter is the rivalry between the Thousand Sons and the Grey Knights. The Sons of Prospero see the Sons of Titan as deluded rivals daring to challenge their psychic mastery. The Grey Knights are sworn to oppose all servants of Chaos, and they have ventured out time and time again to halt the plans of the Thousand Sons just before they come to fruition. The sorceries of the legion wash off the warded silver armor of the Knights, unraveled by their librarians, just as the blasts from Silver Towers do when they face Grey Knight strike cruisers in battle. The Thousand Sons are thus forced to rely on more mundane methods to defeat their foes, and as such still maintain more conventional methods of waging war in case they come face to face with foes like the Grey Knights. The seers of the Legion have long peered into the tides of the Warp, and believe there is some sort of empyric connection that binds the Arcana and Sanctic Astartes, though this connection is more tenuous than might be expected.

Beliefs and Warcry

The Thousand Sons most often fight Imperial foes, but they are no strangers to clashing with xenos. They have not forgotten their goal of entering the Black Library, and have maintained constant pressure upon the Webway, traveling its many halls while killing the Aeldari who stand in their way. So too have they maintained a rivalry with the Alpha Legion, whose spies and saboteurs have proved irritatingly effective at unraveling plans centuries in the making. Nonetheless, the Thousand Sons are utterly convinced of the righteousness of their cause. Knowledge is power, and by their standard none are more powerful than they. Every plan, every scheme, every action is designed to increase their knowledge, though such dark wisdom is inevitably corrupting. Such knowledge and lore has led to purges of entire planets, as the Sorcerers whisper arcane secrets in the dreams of mortals, inspiring madness and rebellion that is ruthlessly put down by Imperial authorities. However, for the Thousand Sons, the damnation of entire worlds is inconsequential compared to the thought of gaining power.

All manner of beliefs are encouraged in the legion, and no beliefs are considered heretical. Truth and fiction are considered of equal importance, determined only by where one stands, thus relativity reigns supreme. Spoken words are of little matter, it is intention that counts, and as such, the sorcerers seek to understand each other's intentions when forced to rely on each other to further one of their myriad schemes. Their patron, Tzeentch, is empowered by such deceit and planning, and benefits whether or not his puppets recognize his sovereignty. Thus the legion acts as both puppets and slaves, aware and unaware of reality as they dance like marionettes tied to the strings of fate. Knowledge of such predetermination might drive mortal men to insanity, but the Thousand Sons have transcended such base notions.

When entering battle, the first thing the foe hears is the howling of the Shogaal and the squawking of Tzaangors. All manner of unearthly sounds designed to terrify herald the arrival of the Fifteenth Legion, followed by the first wave of sorcerous blasts, melting defenses to slag even as the defenders are mutated in the fires of change. The Sorcerers fight in silence compared to the howling of their Rubrics, whispering their incantations as they march toward their goals. The Shogaal wear little armor, but the Sorcerers wear the same battle-plate as they have since the Heresy. All are a uniform blue and yellow, marked with the iconography of their Cult as well as such as Eyes of Magnus. Their shoulders all bear the symbol of a snake devouring its tail, and many sorcerers bear crests and horns on their helmets. Each sorcerer bears different markings and mutations bestowed by their service to Chaos, a maddening kaleidoscope that ensures no two Astartes are precisely the same.

The Tower of the Cyclops shook, unearthly energies radiating as lightning bolts continually struck the surrounding towers, mutating them before the wards forced them back into conformity. Inside the tower, the Mad Cyclops raged and tugged at the enchanted chains that suspended him in midair, inextricably bound. Far below him, the lone inhabitant of this asylum watched the massive form of his father above. This visit, however, was unlike the many which had occurred before; this visit was filled with hope.

Ahriman, the Osirian Dreadnought Master, had come to watch over his father an uncountable number of times since the tower was constructed. Time had little meaning here in the Warp. But in his meditations, Ahriman had discovered the truth behind his father's bargains. Magnus had assumed he was merely taking the power he required, but the debt caught up to him by the end of the Heresy, and he lost his humanity and mind, the only things he truly treasured. In exchange for every year of borrowed power, Magnus received 99 years of madness.

But by Ahriman's estimation, his father would be in this state for 9999 years, payment for around one hundred and twenty years since the time he joined the False Emperor's Crusade. If his theory was correct, Magnus should regain sanity by the end of M41. Thus while many other Thousand Sons traveled to join in Sigismund's 13th Black Crusade, Ahriman sat here by his father's side, waiting to see what fate had in store…

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A/N: Behold, the first Traitor Legion! In my drive to make my story different, I wanted the legions dedicated to a particular Ruinous Power to emphasize a different aspect of their deity than canon does. Thus while canon Thousand Sons epitomize psychic mastery, the sons of Magnus in the Leonine Heresy put more attention to the sheer madness and mutation that is Tzeentch. Thus Magnus is utterly insane, and the Rubrics are bestial and take many forms compared to the real dusty automatons. Next up will be the Death Guard, where we will learn just how true rings the trope 'Good is not Nice'.

Sharrowkyn, out.