The Roboutian Heresy

by Zahariel

Inspired by the great Dornian Heresy of Aurelius Rex, here is an alternate timeline to the Warhammer 40000 universe, where Guilliman turned traitor instead of Horus, and led half the Legions in rebellion against the Emperor. The Index Astartes are done for all Legions. Now, the Times of Ending have begun ... Also has a TV Tropes page now !

14. Index Astartes : Thousand Sons

I do not own the Warhammer 40000 universe nor any of its characters. They belong to Games Workshop.

Inspired by the Dornian Heresy, by Aurelius Rex

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Index Astartes – Thousand Sons : Heirs to Ashen Dreams

In the Imperium, to be a son of Magnus is to stand forever apart of the rest of Mankind, isolated from even their Astartes cousins. As some of the most powerful psykers serving the Emperor, the Thousand Sons bear a heavy burden. Their numbers forever kept low by the very source of their power, they are scattered across the galaxy, fighting in endless wars at the sides of armies that look upon them with fear and distrust. Dark visions of their lost homeworld, brought to ruin ten thousand years ago by the savages of the Sixth Legion, haunt them to this day. They are melancholic lords of war, who have witnessed the slow fall of the Imperium, century after century, into superstition and ignorance. Their Primarch lost to them, they are left with no clear purpose in the galaxy, safe for the protection of an Imperium that grows more hateful toward them with each passing decade. Now, they are only pushed forward by their duty to the Emperor, their father and Mankind – and the distant, shrouded hope of a better future …

Origins

Humans fear what they don't understand, and they hate what they fear. This simple fact has held true from the dark ages of Old Earth to this day, and it was it that led to the colonization of Prospero, in the twilight day of the first galactic Human Empire. At first glance, there was nothing on Prospero that could draw a human population : the planet was one, giant desert, far from any major Warp-road crossways. Yet these bleak features were precisely what led the first colons to sail for the Planet of Dust.

As the Dark Age of Technology drew to a close, the psychic potential of Mankind began to awaken. Psykers and mutants started to appear, and with the collapse of the Eldar Empire beginning, their apparition heralded Warp Storms and other disasters. These strange individuals, wielding unknown powers, were soon perceived as those responsible, and persecuted across the width and breadth of the galaxy. On countless thousands of worlds, vast pogroms were organized to purge the human population of any genetic deviancy. Though History would vindicate these massacres when the Age of Strife erupted and feral psykers enslaved entire worlds, untold billions of innocents were slain in the process.

Yet not all psykers were willing to let themselves be slaughtered, nor were they ready to turn against the rest of Humanity to protect themselves. Instead, they chose another path : exile. Using whatever ships they could obtain, the gifted of a thousand worlds fled, seeking a place where they would be safe from persecution, a place where they could master and hone their talents until such a time as Mankind was ready to welcome them back.

Drawn to each other, the fleets of exiles finally settled in the dark reaches of the Ultima Segmentum. They named their world Prospero, in homage to an ancient legend from Old Earth, and began to build their own civilization, hidden away from the rest of the galaxy. STC devices and careful use of their powers enabled them to live an austere existence, appropriate to the research and meditation that were required to keep their psychic might under control. Pyramids and libraries were built within which entire generations learned and discovered yet more knowledge. Yet even then, the exiles of Prospero did not know peace.

From the deserts came the Psychneuein, predators that fed on those psychically gifted by pulsing their eggs into their brains. How exactly such nightmarish creatures came to be is unknown – certainly they weren't the product of natural evolution, for there was no way they could have sustained themselves prior to Prospero's colonization. Some claim that they were the result of the psykers' presence influencing the local wildlife, while others are persuaded that they were beings of the Empyrean that had found a way to enter the Materium in order to feast on Prospero's population.

Regardless of their origin, the Psychneuein harassed the people of Prospero for centuries. Most of the time, they preyed only on lone wanderers, but sometimes they attacked one of the planet's cities in immense swarms, breaching its lines of defenses and slaughtering its inhabitants. Still, the Prosperine civilization endured, though its endless struggle against the psychic predators kept it from developing further – until salvation came from the skies.

In a strike of flame, a life-pod crashed into the very center of the great plaza of Tizca, Prospero's greatest city. At first, the inhabitants recoiled from the object, fearing that it was the sign that those that had forced their forebears to exile had found them. But when no further bombardment came, they dared to approach the object, and were met by an infant floating in the air, psychic power crackling around him. His skin and hair were both red, and he looked at the world around him with two wide, curious eyes.

Had the child landed on any other human world, he would doubtlessly have had to fight for his life as its inhabitants attempted to destroy him, thinking him to be the spawn of the Warp. But the Prosperine were used to the physical alterations that often accompany psychic potential, and they welcomed the child into their society.

Under the guidance of Amon, the leader of Tizca, and other teachers, Magnus quickly learned all that the exiles of Prospero had uncovered of the Empyrean. He mastered all the Arts, as the wielding of the Warp's power was known to them, and soon rose to surpass all of his mentors. He studied the Prosperine philosophies, and attended the lessons of a many a Tizcan scholar.

Paralleling Magnus' intellectual growth was his physical transformation. His body went through the stages of adolescence at an incredible speed, and barely a few years after his arrival, he was a giant of a man, towering above even those whose physical alterations manifested in thin, tall bodies. With a wild mane of crimson hair and a face that was at once handsome and full of wisdom, Magnus was a demigod among mortals.

Through his genius and charisma, Magnus quickly rose to become the leader of Tizca, despite his young age. His first act was to begin a campaign of extermination against the Psychneuein and the other predators of Prospero, so that civilization could resume its advance, freed from their threat. One by one, the prodigal child sought and destroyed the beasts' nests, forcing them to flee deep into the deserts. Only when he confronted the Psychneuein-Prime, the oldest of all the Psychneuein on Prospero, was Magnus finally faced with a challenge. Such was the might of the beast that, despite all his knowledge, power and experience, Magnus was wounded deeply in the battle, losing one of his eyes to the creature's claws.

The beast was an abomination, as much a creature of the Aether as it was from the physical plane. It was a grotesque insect, several time the size of its foe, buzzing with the sound of wings that defied the laws of physics and evolution alike. It stared at Magnus with two enormous, faceted eyes, and though its face was as ugly as the rest of it, the young man couldn't help but feel that it was mocking him.

The Psychneuein-Prime fed on Magnus' power, draining him of the might that had been his since the first time he had opened his eyes. Over and over again, he tried to destroy it, unleashing bolt of lightning after bolt of lightning, but all his attacks dissipated harmlessly long before they could reach their target.

A clawed appendage burst into motion, faster than anything of the material plane had any right to move. Magnus barely managed to move his throat out of its way, but it came back down in a second assault, and despite his desperate dodge, the claw reached his face. It tore into the skin of his flesh and cut right through his right eye. Magnus screamed as agony unlike anything he had ever felt spread through his body – the pain was only partially physical, for the Psychneuein-Prime's attack had also damaged his very soul.

Refusing to let the pain weaken him, Magnus focused once more on his foe, using his torment to fuel his rage and will to triumph. With a great roar, he jumped at the beast, clasping its wings with his bare hands and pushing it to the ground with his weight. Like a barbarian, he tore the wings from the creature's back, before bringing his fists down upon its grotesque skull, over and over again, until all that remained was a smear on the sand.

Then, groggy from the pain and exertion, Magnus staggered away from his kill, beginning the walk back to Tizca, bleeding from several wounds. All of them were already healing, except for the last one he had taken – this one, he knew he would carry for the rest of his day. But the loss of his eye had taught him a lesson he would not forget. His hand pressing on the gaping wound, Magnus vowed that he would remember that there were some things that couldn't be defeated by the power of the mind alone, some foulness that needed to be banished with brawn and righteousness.

While it never managed to fully eradicate the scourge of the Psychneuein, Magnus' crusade reduced them to a mere nuisance. The other Prosperine cities rejoiced at that liberation, and Magnus became the leader of a coalition that spanned the entirety of the planet, receiving the title of Crimson King. Under his leadership, Prospero entered a golden age of discovery and culture, with the arts, both physical and ethereal, reaching new heights.

When the Emperor reached Prospero, Magnus was expecting his father's arrival. The Primarch was unique among his brothers in that he alone remembered his entire existence, from the moment the spark of life had first touched his infantile body in the Master of Mankind's gene-laboratories. He remembered touching minds with the Emperor then, and the two had remained in distant psychic contact ever since, Magnus guiding his father to Prospero so that they could be reunited in body as well as in spirit.

Tough the people of Prospero feared the arrival of the Emperor at first, Magnus assuaged their fears, telling them that the Great Crusade was the very thing their ancestors had hoped Mankind would accomplish – the time when they could return to their species, free of prejudice and hatred. He told them that he had spoken with his father many times before, and that they could trust into His wisdom, for He was the epitome of what Prosperine philosophers believed into – the greatest human psyker to have ever lived.

Yet the reunion was not only a cause of joy, for the Emperor brought dire news to Magnus, news that He had believed it was too risky to exchange through the whimsical tides of the Empyrean. The warriors created from Magnus' gene-seed, the Fifteenth Space Marine Legion, were dying out, afflicted by a terrible plague of mutation. The flesh-change, as it had become known, had emerged among the Legion's ranks shortly after the beginning of the Great Crusade, and its symptoms were appalling. At first, the psychic powers of the afflicted warrior increased drastically, and the alterations could be contained through the exercise of one's willpower. But sooner or later, the pressure became too much, and the mutations overwhelmed the Legionary, reducing him to a whimpering, senseless beast that had to be put down.

Already, thousands of Astartes had been lost, and the recruiting process had all but stopped as the Apothecaries refused to expose more souls to the flesh-change. The Emperor's best savants and gene-smiths were unable to stop it, and Magnus, with all the knowledge of Prospero, was the last hope of the thousand sons he had left.

The Great Crusade

The history of the Fifteenth Legion, up to the emergence of their affliction, had been a glorious one. Like all Legions, their first recruits had come from Terra, more specifically from the Achaemenid Empire. Situated in the Middle East, in what had once been called the Persian Empire, it had been an alliance of powerful tribes, whose shared might had shielded them from the worse of the Age of Strife's depredations. When the Emperor rose on Terra, they had been among the first to join Him, and for that, and because their gene-pool was relatively untainted, they became the source of the first Fifteenth Legion's aspirants.

One of the first battles in which the Fifteenth Legion took part was the Boeotian Pacification. For more than a hundred and fifty years, the ruling monarchy of Boeotia, the Yeselti, had dragged on their integration into the Imperium. Always the kings would find more excuses to delay the process, and for a long time the Emperor tolerated this. But as the Unification of Terra drew near, the Master of Mankind's patience with the Boeotian monarchs ran out. After one last, final warning, which was only met with yet more excuses, the Emperor dispatched His army, led by the first contingents of the Fifteenth Space Marine Legion.

The resulting battle was as devastating and one-sided as one might imagine. Boeotia fell in twelve days, and it only took that long because the Space Marines took care to avoid inflicting unnecessary civilian casualties. With their mighty psychic powers, the Legionaries ripped apart fortresses and drove entire battalions mad, before finally confronting the Yeselti kings and putting an end to a bloodline that had endured for thousands of years.

After that, they had taken to the stars, and quickly accumulated a tally of compliances, for they were both gifted diplomats, wearing the mantle of scholars and teachers with the human civilizations ready to join the Imperium, and the cloak of psychic warriors when they faced resistance or the horrors of Old Night. World after world had been claimed by the Expeditionary Fleets under the command of the Fifteenth Legion, until the flesh-change had begun. Then, everything had gone wrong. Many Imperial forces had been decimated by mutated Legionaries, driven mad by their hideous transformation. In several cases, the survivors had been purged by other Space Marines, in the hope of hiding what had happened. And they had partially succeeded in that, for the Emperor Himself had taken measures to keep the affliction of the Fifteenth as secretive as possible. Still, rumors had spread among all the forces of the Great Crusade and across the newly born Imperium. Distrust toward the Fifteenth Legion was growing just as quickly as their numbers diminished.

Many among the lords of the Imperium suggested that the Fifteenth Legion should be expunged from all records, its surviving members slain before the flesh-change caught them, and its Primarch bound to the Emperor's service in the shadows – after he was himself tested for the taint, of course. The wound Magnus had taken in fighting the Psychneuein-Prime had long healed, but the empty eye socket had been replaced by smooth skin, earning him the nickname of "Cyclops" by those who saw it as proof that he was tainted as well.

'My sons' legacy shall not be reduced to an empty pedestal beneath the roof of the Hegemon.'
Magnus, Primarch of the Fifteenth Legion

But Magnus was determined not to let his sons' story come to such an ignoble end. He dedicated himself wholly to his task, spending several years buried in one avenue of research after another, his Legionaries who became afflicted with the curse put into stasis until he succeeded. He conferred with the surviving Apothecaries and gene-smiths, and poured over documents made available to him by the Master of Mankind, describing how the Astartes had been created.

The Crimson King attempted many cures, but all of them failed, doing little more than slowing the progress of the degeneration. Finally, in one last desperate bid, Magnus created a great arcane circle in the greatest of Prospero's deserts, farthest from any city, and cast his mind into the Aether, seeking a way to find his sons in its fathomless depths.

The words came from a thousand voices, all with subtly different intonations that gave them a different meaning.

'You are mine,' shrieked the false god. 'You have always been and will always be MINE ! Only I have the power to save your sons. Obey me, and I shall grant you their salvation !'

'Lies !' shouted Magnus, power crackling all over his hulking frame as he stood, defying the power who claimed to hold fate in its hands. 'You have nothing ! You are nothing ! Only lies and deceit ! You have no power over me !'

The crimson giant froze as he screamed the last words, a great revelation dawning upon him.

'You have no power over me,' he repeated, slowly, only now understanding their truth, ' and I don't need your help. You have no power over anyone that they did not give to you ! And I give you nothing. Begone, and trouble me no more !'

'This is not over, Magnus !' threatened the voices. 'There will be a reckoning for this ! You cannot defy me, for I am the Architect of Fate !'

'You are nothing,' replied Magnus, and he turned away from the one who had promised him the truths of the universe. 'Nothing but the lies we tell to ourselves, and I choose the truth. I shall free my sons of your poison, no matter the cost to myself – but I will never call upon you. Do you hear me, daemon ? Never !'

The image of the Primarch vanished as he returned to the world of flesh and matter, leaving the thousand-headed god alone with a web of fate unmade by the rebellion of he who should have been its champion. For a timeless moment, there was silence, as the minions of the god looked upon their master, fearful of his anger. Then, dark laughter resonated through the Warp, as the God of Change delighted in this new development and the opportunities it offered.

'There will be a reckoning,' the voices repeated, calmer this time. 'Kairos ! My Oracle ! Attend me !'

No one outside of the Fifteenth Legion's highest circles know what he found there, but it worked. As Prospero trembled from the psychic feedback of the Crimson King's gambit, Magnus put an end to his sons' degeneration. Whatever mean he employed, it left him much weakened, according to Kallidus, a remembrancer who attached himself to the Crimson King much before the remembrancers became an official part of the Great Crusade. Many theorize that the Primarch used his own considerable power to extend some kind of blessing upon all carrying his bloodline, warding off the mutagenic effects of their psychic powers. The events that followed the end of the Scouring and the loss of the Cyclops, many decades later, certainly point us toward that conclusion.

What is known, however, is that during that journey through the Sea of Souls, Magnus learned of the existence and terrible threat of the Chaos Gods, though he didn't understand exactly the import of what he had seen immediately. At once, he went to the Emperor, telling his father of the four terrible powers he had witnessed, and the numberless legions under their command. Despite having just saved his sons from abject degeneration, Magnus was greatly agitated, on the verge of hysteria as the horrors he had seen flashed endlessly in his mind.

The Emperor, through a mix of psychic purification and fatherly reassurance, calmed His son's fears. He told Magnus that what he had seen in the Warp was indeed a terrible threat, but one that had been known to Him for a long time, and that He had taken measures against it. In time, the Emperor promised, Magnus would be told what these measures were, and the true nature of this trans-dimensional enemy. But for now, the Crimson King had a great task to attend to – there were sons who needed his help to rebuild their all but ruined Legion. Magnus, who had spent his life so far as a scholar, a leader of men and a researcher of the arcane, now needed to learn the arts of war.

The Crimson King journeyed to Terra, where he spent several months alongside his brother Perturabo, who had been rediscovered by the Emperor while Magnus toiled to save his sons. The two of them bonded quickly, and explored the ruins of Old Earth side by side, revelling equally in the ancient discoveries they unearthed. However, their time together soon ran out, and both of them went on to take official command of their Legions, each pledging to always stand at the other's side if they ever needed it.

Magnus named his Legion the Thousand Sons, so that they would always remember how close to utter extinction they had come, and would ever struggle to avoid facing such a fate again. In return, they changed the Legion's colors, painting their armor in red to honor their Primarch, and taking as their emblem the sun-rune of Prospero. For just as night would always be followed by day, so had the sons of Magnus returned to glory once more.

The Fifteenth Legion returned to the Great Crusade, its Primarch leading it to new victories and conquests. With a new flux of recruits from Prospero, the numbers of the Thousand Sons swelled, though they never quite reached those of the other Legions. At Magnus' command, the Legion was reorganised, with the Cults being installed as a way for the sons of the Crimson King to best learn how to master their power.

The Thousand Sons' Cults

When Magnus took command of the Fifteenth Legion, he created the Legionary Cults, a system that would allow his sons to learn the Arts in a controlled fashion, so that they would never lose control of their powers. Inspired by the teaching structure of Prospero, each of the Cults specialized in one particular type of abilities, and almost every single Legionary belonged to one – only those with too little psychic potential weren't part of this system.

There were five Cults in all. The Corvidae focused on precognition, the Athanaeans on telepathy, the Pavoni on physiokinesis, the Pyrae on pyrokinesis, and the Raptora on telekinesis. At the head of each cult was a Magister Templi, the Astartes best versed in the Cult's secrets. Though the title held no official authority, those who carried it were always Captains at the least, and it granted them some seniority over those of same rank.

Now, with the Thousand Sons much diminished and scattered across the galaxy, the Cults still exist as a classification of powers and schools of training. But there are no Magister Templi – hierarchy is determined solely by one's knowledge of the Arts.

The Cults' teachings eventually spread to the Librarius of the other Legions which didn't frown upon the use of psychic powers – safe for the Sixth Legion, which had always had its own tradition of psychic users (though the sons of Fenris claimed them to be something else entirely) and would never have allowed the Fifteenth's "maleficarum" to taint it.

Despite their low numbers, the Thousand Sons earned a tally of victories worthy of any Legion. Few enemies in the galaxy could match the strength of the Legiones Astartes, and when combined with the psychic might that flooded through Magnus' gene-line, almost none could even hope to resist. The Fifteenth Legion shattered alien empires and human tyrants alike, combining bolter and blade with the secrets of the Cults.

On every human world they encountered, regardless of whether compliance was achieved through force of arms or diplomacy, the Thousand Sons sought all the knowledge that the civilization had managed to preserve through the Old Night. Not the technological lore, which would have put them at odds with the magos of the Mechanicum, but the wisdom of the lost ages, the philosophical texts and historical memoires. These documents were copied and sent to Prospero and the other worlds of the circle of library-worlds that came to be known as the Prosperine Dominion.

The Prosperine Dominion

During the time of the Great Crusade, most Legions had at least one planet under their direct control, to serve as a recruiting ground, training place for the aspirants, or a hundred other uses. In most cases, the homeworld of the Legion's Primarch served as the core of that nearly-independant empire, apart from a few obvious cases (such as the Imperial Fists).

The Thousand Sons were never great enough in numbers to warrant a full sub-empire of their own, and instead dedicated the worlds under their protection to another purpose. The Prosperine Dominion, as it came to be known, was composed of a dozen planets at its peak, half of which were library-worlds, dedicated solely to the storage and study of ancient knowledge. The Dominion was centred on Prospero, with each world being only a short distance from the Legion's homeworld. There, entire lineages of librarians spent their entire existences cataloguing the findings of their Astartes masters from across the galaxy. To the Imperium's intellectual elite, the right to peruse the archives gathered by the Thousand Sons was beyond priceless.

Things have changed, of course, since the Burning of Prospero. The Prosperine Dominion still exists, but it is much reduced in size, and its worlds serve a much different purpose.

Despite the salvation Magnus had brought them, the reputation of the Thousand Sons remained muddy throughout the Great Crusade. The marks of Old Night remained on many worlds, bringing with them tales of wild psykers and the horrors they had wrought. Even among the Primarchs, Magnus' status was ambivalent : some, like Perturabo, Horus and others, regarded him as a good strategist and a powerful warrior, who could also be a diplomat when it was required. Others, first among whose were Mortarion and Russ, disliked his reliance on psychic powers, and the fact that his Legion was mostly made of sons of Prospero – a world either of them would have put to the torch had they been the first to reach it.

These tensions between the Space Wolves and the Thousand Sons reached a paroxysm during the Battle of Shrike. For several years, forces of the Word Bearers had been engaged in battle against the Avenian Empire, a human civilization that had refused the offer to integrate the Imperium. Lorgar's sons, unable to break the Avenian Empire's hold over the Ark Reach Secundus sector, called for aid from their fellow Legionaries. Both Magnus and Russ answered the call, though if Lorgar had known they would both arrive, he would doubtlessly have arranged matters differently.

Soon enough, the arrival of two more Legions managed to overcome the Avenian resistance, and the Imperial forces cornered the resisting empire on its capital-world, Heliosa. The Avenian fought with grim determination, and the battles were fierce, but eventually they were forced back into one last city, Shrike. This city was defended by gigantic fortifications, shielded from orbital bombardments and guarded by hundreds of thousands of soldiers. The Space Wolves launched assault after assault, but were pushed back each time, taking grievous losses. When the Thousand Sons arrived from the subjugation of another city, they immediately deployed their powers upon Shrike's defenders.

Avenian soldiers turned on their comrades, while entire sections of the fortifications fell apart under the telekinetic grasp of the Raptora Cult. The sons of Magnus charged into the openings the psychic assault had created. In a matter of hours, the city had fallen, with the last leaders of the Avenian Empire either dead or captured. But another battle almost erupted immediately.

The Space Wolves felt cheated of their victory by the Thousand Sons, denouncing their use of "black magick" and "maleficarum". The Thousand Sons replied by calling the sons of Fenris a bunch of ignorant barbarians and hypocrites, pointing at the Rune Priests standing right among their accusers. Tempers ran hot on both side, and Russ and Magnus would have come to blows there and then had it not been for the intervention of Lorgar. The Primarch of the Word Bearers managed to separate his brothers, half by diplomacy and half by swearing that his own warriors would shoot them all if they opened fire. Each Legion returned to its ships and quickly left the planet, leaving the Seventeenth to take care of the campaign's aftermath and creating a feud that would only grow worse over the years.

When the Ork empire was shattered at the battle of Ullanor, the Emperor summoned His sons to witness the Triumph that would mark this greatest of victories. Magnus came to congratulate his brothers who had taken part in the battle, but also because he had sensed some new developments in the Sea of Souls, and wished to talk to his father about them.

We do not know what the Emperor and Magnus talked about, but when the Master of Mankind announced His decision to withdraw from the Great Crusade and hand over overall command to Horus, He also declared that the Crimson King would accompany Him back to Terra, to help Him in the work ahead. This caused much speculation among the Imperial forces present about the nature of that work, but the Emperor also refused to speak of what He planned – even to Horus, when the newly appointed Warmaster asked.

Magnus selected the elite of his Legion to come with him back to Terra. This selection didn't target the most powerful warriors, but the keenest minds, those who would best be able to aid in the Emperor's grand project. The rest of the Fifteenth Legion was placed under the command of First Captain Ahzek Ahriman, and seconded to the newly renamed Sons of Horus, so that the new Warmaster may rely on their aid in his new duties.

Ahzek Ahriman, Keeper of the Lore

A Terran-born, Ahzek Ahriman was a psyker of incredible power, possibly the most powerful to have ever lived apart from the Emperor and the Primarchs. Born among the clans of the Achaemenid Empire, he had been part of the very first wave of aspirants to be inducted into the Fifteenth Legion, alongside his twin brother Ohrmuzd. They both quickly rose in the ranks, but tragically, Ohrmuzd was lost to the flesh-change before the Legion was reunited with Magnus and the Crimson King put an end to the plague of mutation.

According to ancient texts, the death of his brother changed Ahriman, turning him more cold and distant. He dedicated his life to the Legion, and became its First Captain as well as the Magister Templi of the Corvidae. When Magnus was recalled to Terra by the Emperor, most expected that Ahriman would accompany his Primarch. Instead, Magnus gave his First Captain command of the Fifteenth Legion, as well as the Book of Magnus, a grimoire in which the Crimson King had written all the arcane knowledge he had accumulated over the centuries.

The Book of Magnus proved instrumental when Ahriman had to lead a circle of Librarians from the Fifteenth and Sixteenth Legions during the incident of Xenobia Prime to save the soul of Horus Lupercal from the Primordial Annihilator.

On Terra, Magnus was finally revealed the true nature of the dark powers he had sensed in the Warp decades before. He learned of Chaos, and of the Emperor's plan to defeat it once and for all. The Master of Mankind had discovered an ancient Webway gate on Terra, and sought to master the Labyrinthine Dimension, so that Mankind could use it to bypass Warp travel entirely. By combining this with the peace that the Imperium would bring to the galaxy, it was His hope that eventually, the Dark Gods would starve, and the ancient corruption that the War in Heavens had created would be erased.

The Crimson King saw at once the scope of that plan, and the titanic efforts that would be required for it to have even the slightest chance of working. At his command, his sons began to work alongside the Emperor's savants, bringing their knowledge of the Warp to the research. Swift progress was made, but there remained much to do before the Emperor's great work could even begin to be tested. Magnus feared that it would take centuries before the work was complete, and doubted that the Dark Gods would remain silent during that time. Almost unconsciously, he began to devise another, alternative plan – one that was just as titanic in scope, but could be implemented more readily.

One day, not long before the Nikaea Council was called, Magnus couldn't keep his silence any longer, and presented this plan to his father. Magnus was hoping that Mankind could evolve like the Eldar, gaining species-wide psychic powers that could be catalysed into creating "gods" inspired by the Imperial Truth to shelter the Imperium from the depredations of the Ruinous Powers. With the Imperial Truth as the basis for morality and the Emperor's guidance, it was his belief that they would avoid the fate of the Eldar.

The Emperor chastised His son, remembering him that He had proclaimed, at the beginning of the Great Crusade, that there would be no gods in the galaxy. Magnus argued that these gods would actually be nothing more than psychic projections, constructs of will and ideals. But the Master of Mankind pointed to those of the Eldar who had not fallen to the darkness, and how they had begun to worship their own gods, believing in the creation myths that their ancestors had woven out of cloth aeons before. Magnus' plan depended on the Emperor being always present to ensure Mankind did not follow the same path to decadence as the children of Isha, and that notion was abhorrent to the Emperor. It was His hope, He explained, that one day Mankind would no longer need Him.

Chastised, Magnus returned to his work on the galactic network, but his research was soon interrupted when the call came for all Primarchs available to travel to Nikaea, where the question of psychic powers in the Astartes Legions would be addressed once and for all.

Remembering his recent rebuke, Magnus chose to remain silent during the entirety of the Council, leaving others, such as Perturabo, speak in the defense of the Librarius. When the Emperor gave His judgement – that the Librarius be maintained, as a weapon of war and a way of controlling psychic powers – he was vindicated, yet found himself more worried than joyful. Mortarion was furious, but chose to trust in the Emperor's decision, but Leman Russ was far from being as accepting of the Master of Mankind's decree. The Wolf King publicly denounced the decision as a terrible mistake, and when Magnus tried to talk to his brother, to convince him that their father knew what He was doing, the lord of Fenris struck at the Cyclops.

Magnus was so surprised by his brother's aggression that he didn't react to it, and was only saved by the intervention of his Equerry, Amon. The old warrior hurled himself between the two Primarchs, and was nearly cut in half by the Wolf King's blow. Russ fled from his crime before he could be stopped by the other Primarchs or the Custodians, while Magnus tended to his fallen mentor, desperately trying to save his life.

This final event cast a dark shadow over what should have been a great victory for the Thousand Sons. As Amon was placed within a Dreadnought, Magnus met with his son Ahriman, telling him to care for Horus during their journeys to come – for the Crimson King could sense a great darkness gathering in the Sea of Souls. After one final meeting, the Primarchs went their separate ways, Magnus returning with his father to Terra once more, to continue his labour on the Great Work. At least, this time, his old friend Perturabo would come with him, and while he couldn't tell him of the Emperor's designs yet, Magnus relished the opportunities of more discussions with his brother.

Years later, while Perturabo was away dealing with a xenos attack on Olympia Horus returned to Terra. Magnus listened to his brother's tale of the Interex, and of the assault Lupercal had suffered. With the Emperor's approval Magnus told his brother all he knew of Chaos and its daemonic servants, at long last relieving himself from the burden of secrecy. Horus was angry that such an important truth had been concealed from him, and hurt that his father hadn't trusted him with it. But he put aside his feelings, and focused on learning all that he could of this new threat.

While he was silently proud of Ahriman for succeeding in saving Horus from the Dark Gods' grasp, Magnus could feel that this was but the first strike of a prolonged conflict. At long last, the Ruinous Powers had made their move against the Imperium. The Warp was roaring, and all members of the reunited Fifteenth Legion could sense the same thing – this was not over. In fact, it was only beginning.

Mere hours after the arrival of Horus, a ship bearing the emblem of the Seventh Legion emerged in the Sol System. Commanding it was Captain Alexis Pollux, who described himself as "once of the Imperial Fists". Pollux told Magnus and Horus of their brothers' betrayal. Guilliman, Sanguinius, Ferrus Manus, and his own gene-sire, Rogal Dorn, had turned against the Emperor and slaughtered those of their sons who would not follow them into rebellion on the fields of Isstvan III.

This revelation shook Magnus to his core. Yet even as Horus began to plan the counter-strike to Guilliman's betrayal, seeking to take advantage of the fact that it had been revealed early, the Crimson King felt that this, too, wasn't the end – not even the true beginning …

The Burning of Prospero

Even as Horus raced to Terra, filled with new knowledge of the galaxy, the forces of Chaos were striking another blow through their unwitting pawns thousands of light-years away. Leman Russ had returned from his Errance, his mind bent on averting visions of psychic doom for the entire human species.

Through extensive research of the logs of the vessels who escaped the Rout's onslaught and the testimonies of those who were present, both human and Astartes, we now have a much clearer knowledge of the proceedings of what would come to be called the Burning of Prospero, or the Razing, depending on the translation of the original Prosperine term that is being employed.

Prospero was defended by several orbital installations, as well as a handful of Legion ships that took turns to scout the system's edge. When the Space Wolves armada arrived, the one scouting was the Tlaloc, the ship of the current commander of the forces present on Prospero : Iskandar Khayon, whose name would come to echo into legend for his defense of the doomed planet and his actions during the rest of the Heresy and beyond.

Iskandar Khayon 'The Black', Scourge of the Wolves

Born of Prospero, Iskandar was the officer in command of the Planet of Dust's defenses when the Space Wolves attacked the world. This rank had been bestowed upon him by Magnus himself after the Siege of Ullanor, and while Iskandar resented being taken away from the frontlines, he soon learned that his Primarch had very good reasons to send him home.

On his arrival at Prospero, Khayon learned that his mortal sister, Itzara, had fallen victim to some of the few remaining Psychneuein. She still lived, but by the time the chirurgeon-servitors had removed the larvae from her brain, almost half of it had been devoured or excised. She had been reduced to an idiotic child, unable to even move.

Though he was an Astartes, Khayon still felt as great a connection for his mortal family as any human who ever lived – something which was regarded as both a blessing and a curse by his battle-brothers. He refused to have his sister live that way, and brought her to the tech-adepts of the Prosperine Mechanicum outpost. There, she became something more, and less, than human : the central consciousness of the Anamensis, a construct-mind of hundred of brains, linked together and capable of directing the systems of an entire ship. The Anamensis was installed within Khayon's own ship, the Tlaloc, where she acted as the vessel's machine-spirit.

During the Burning, Khayon led from the front, marshalling the defenders of Prospero with all the skill and fury of a son who had seen his parents' home wiped from existence by orbital bombardment. He fought personally against the Rune Priests, confronting six of the Rout's deluded Sorcerers and obliterated them in a display of psychic power that scorched his armor black, a color it would keep for the rest of Khayon's life, bearing it as a symbol of all that had been lost on Prospero. This led to his nickname as "Khayon the Black".

It is said the Khayon was the first of the Heralds of Prospero, these mystical warriors who walk to war with the ghosts of the fallen world alongside them. Accounts from the Roboutian Heresy speak of how, during the Siege of Terra, he let loose a horde of vengeful spirits upon the traitor forces, tearing an entire Company of Imperial Fists to pieces. Afterwards, during the Scouring, he exorcised thousands of Neverborn, banishing them back to the Warp with a skill unseen in the rest of the Imperium. These daemons remember Khayon well, and whisper his name with whatever passes for fear in their inhuman minds. A hundred years after the end of the Heresy, when the Thousand Sons and their allies laid siege to the Fang on Fenris, it was Khayon who was granted the honor of leading the charge.

After the end of the Scouring and the loss of Magnus, Khayon had a violent argument with Ahriman, the reason of which is unknown, and left the Imperium with his old mentor Ashur-Kai and the Tlaloc, never to be seen again.

By using xenos technology, the Space Wolves were able to hide their approach, both from conventional scanners and from the Thousand Sons' psychic senses. Only when they were in range of the orbital defenses did they reveal themselves, unleashing a deluge of assault crafts on the space stations and reducing the few ships to scrap through overwhelming force. In short order, the Space Wolves were masters of Prospero's orbital space. The Razing could begin.

Fire rained from the skies as the sons of Fenris bombarded every city of Prospero, seeking to wipe out as much of its population as possible. Of all the Prosperine cities, only Tizca, the City of Light, had any protection from orbital assault, and even its mighty void shields were soon breached by the combined might of the Sixth Legion's fleet. Ancient libraries and pyramids were annihilated, while the Thousand Sons deployed their psychic might to shield as much of their own fortifications as possible and hurried the terrified citizens of Tizca into the dubious shelter they provided.

In the heart of Tizca stood Captain Khayon, his mind burning with rage and sorrow in equal measure. The son of Magnus had just witnessed the house of his mortal parents explode, and sensed the terrified final moments of his kin. When the Space Wolves landed outside the ruin that Tizca had become, Khayon reached out to those of his brothers who had survived the initial bombardment. There were several hundreds of them, arrayed against the thousands of Wolves coming upon them. Even with the help of the Spireguards, who had managed to gather in order of battle despite the utter chaos, this wouldn't be enough. But Khayon had a plan.

Mind-linked with his battle-brothers, Khayon sent his mind into the desert surrounding Tizca, searching for the primitive minds of the beasts that had devoured his sister's brain. Using ancient words of power that had first been pronounced in the era when the Prosperine had thought to fight the predators of their world rather than flee from them, Khayon summoned the Psychneuein to the battle.

From a thousand nests they came, charging the Space Wolves in their urge to reach the source of the psychic call. Almost every Psychneuein still alive on Prospero had, over the course of the decades, migrated to the surroundings of Tizca, drawn to its bounty of psychic souls like a moth to a flame. The Warp-born predators fell upon the Rout like a cataclysm from ancient myths, driven mad by Khayon's spell. They pulsed their larvae into all the sons of Russ in equal measure, for all of them bore a shard of their so-called wyrd, the power they insisted came from the spirits of Fenris.

Hundreds of Wolves died that way, trashing around as their brains were being eaten from the inside. But soon, the Sixth Legion destroyed the Psychneuein, and resumed its advance on Tizca, determined to punish the Thousand Sons for what they saw as another display of fell sorcery – ultimate proof, though they did not need it, of Prospero's corruption. They reached the destroyed hab-blocks and ran through paved streets, marching straight toward the city's center, where remained the last standing pyramids.

Many and terrible are the tales of the Heroes of Prospero. Ankhu Anen, Guardian of the Great Library, who fought and slew sixty Space Wolves before being felled by the Rune Priest Ohthere Wyrdmake. Auramagma, who turned himself into a fiery meteor as he charged through the ranks of the Wolves, hoping to immolate Leman Russ alongside himself. Khalophis, who gave his life so that the ancient Warlord Titan Canis Vertex would wreak destruction upon the Sixth Legion. But also Ekhos Perreon, sergeant of the Spireguard, who killed a Rune Priest with a knife wrought from the bone of one of Prospero's ancient philosophers. Humans and transhumans alike died well that day, spitting their defiance to the Wolves' face with their last breath.

Yet all the bravery in the galaxy could not overcome such numbers as the Thousand Sons and their allies faced, and soon they were cornered within the last and greatest of Tizca's pyramids, the Pyramid of Photep. There the sons of Magnus prepared to make their last stand – but Khayon refused to let this be the end. Thousands of civilians had taken refuge within the structure, thousands who were the last of Prospero's people. He would not let them perish, not if there was any way to save them.

At the very moment of the battle's beginning, Khayon had reached out to his old mentor, Ashur-Kai Qezremah, whom he had departed Prospero with his ship, the Tlaloc, to patrol the system's edge. Khayon had ordered Ashur-Kai to remain safely away from the Sixth Legion armada, hiding beneath one of Prospero's gas giants. But now, as the Wolves gathered for the final assault, Khayon needed the Tlaloc to risk destruction if there was any chance to salvage anything from the ruination of Prospero.

It was very unlikely that the ship would manage to get close enough for Khayon to undertake his last, desperate gamble before the Wolves overwhelmed the Pyramid of Photep. Yet after all the slaughter they had wrought, the warriors of Fenris seemed unwilling to push their advantage. They surrounded the pyramid but didn't push further.

It only took a few moments for the Thousand Sons to sense what their enemies were planning. In another part of the city, on the ruins of what had been Magnus' own tower, the Rune Priests had gathered. Great and terrible energies were whirling around them, and fifteen Thousand Sons had been crucified in a circle, their power neutralized by xenos drugs. Khayon watched from afar, and soon, an horrible realization dawned upon him. The Wolves didn't simply intend to murder Prospero. Whether the rest of the Sixth Legion knew it or not, the Rune Priests had started a ritual that would channel the Warp energies generated by the world's death and use them to perform a death curse upon every son of Magnus – even on the Primarch himself. The sheer hubris of such a ritual, the arrogance of the self-proclaimed Executioners of the Emperor, almost made Khayon physically sick. It was only because of dark rumors about the Space Wolves' past that he even entertained the notion that was the barbarians were attempting was possible.

But if he couldn't interrupt the ritual, Khayon could still hope to disturb it. The reasons for the Space Wolves' delayed assault was now clear : they were waiting for the Rune Priests' signal, so that the death of the final sons of Magnus would coincide with their ritual's climax. The Captain's desperate plan had suddenly become much less of a forlorn hope.

And indeed, when the Space Wolves finally launched their assault, under the psychic choir of fifteen Thousand Sons undergoing barbaric tortures, the Tlaloc had reached its position just beyond the reach of the Sixth Legion's armada. Channelling all of his power, Khayon used his mental link to his old teacher Ashur-Kai to open a portal through the Warp leading from the Pyramid to the vessel. While a group of Legionaries and Spireguards led a rearguard action to hold back the horde, the surviving people of Prospero poured through the gateway, carrying with them a fraction of the lore the Thousand Sons had accumulated on Prospero. Soon, Khayon stood alone before the passage.

But before he could pass through, a Space Wolf called to him. The warrior of the Rout had become separated from his pack when roaming through the labyrinthine Pyramid of Photep. He now saw a enemy sorcerer, and arrogantly demanded that this foe face him in battle, proclaiming his name as Eyarik-Born-of-Fire, champion of the Sixth Legion, agent of Russ' rightful retribution upon this sinful world.

Rage.

It burned through Khayon's blood like acid. Despite all of his control, all of the Enumerations, from the moment he had sensed the first deaths in orbit, rage had been in his thoughts. As he watched Tizca burn, as he felt each death through his sixth sense, that rage had grown. Even as he led the resistance and planned the survivors' escape, that rage had occupied his thoughts. It would not leave him, and he would not have it any other way.

As the Wolf's challenge rang across the underground room, Khayon knew that the smart thing to do was to cross the portal. What did the warrior behind him matter ? He was but one killer among a Legion of traitors. Could his life balance the billions that had died on this world ? Could his death pay for the civilization the Rout had destroyed ?

Khayon had a duty, to bring the survivors to Terra, to warn Magnus and the Emperor of the Sixth Legion's treachery. His master, his sister, they waited on the Tlaloc, and he knew they wouldn't run until he was aboard. Delaying here would endanger all those he had fought to save.

Slowly, his mind torn between two imperatives, Khayon turned and saw his challenger with his mortal eyes. Eyarik-Born-of-Fire was tall and proud, with the handsome face of a barbarian king. While Khayon's armor was charred black, the Wolf's was in mint condition and covered in runes of warding that made Khayon's mind ache. In his hand, the champion held a power axe, beautifully carved so that the blade looked like a howling wolf. The weapon's runic name was inscribed upon the blade : Saern. Truth, in one of the many Fenrisian dialects.

The rage grew cold. The chorus of angry voices at the back of his mind suddenly went silent. He thought of the Tlaloc, and found that he didn't care anymore. When revenge is all that is left to you, you take it no matter the cost.

'Begone,' spoke Iskandar Khayon. And with that simple word, his will was done.

The Heresy : The War Beneath the Throne

'Hell is empty, and all the devils are here.'
Fragment of an Old Earth's manuscript, estimated M2

With the arrival of Khayon's shattered Companies and Horus' return to Terra, all of the Thousand Sons were now gathered on the Throneworld, safe for a few who had been sent on missions of their own across the galaxy by the Great Crusade's demands. Together, they began to work on reinforcing the defenses built by the Iron Warriors, casting powerful wards that would keep the influence of the Ruinous Powers at bay – many of which still stand to this day.

Yet their Primarch wasn't among them. Just as Khayon crossed the portal, the axe of his dead enemy in hand, the Rune Priests' ritual had reached its end. The power of the Warp poured through them, and a terrible psychic blow left Prospero, coursing through the Sea of Souls at the speed of thought. Though the ritual had failed to reach its intended power, it was still mighty indeed, and might have slain Magnus outright, had it struck him directly.

But Magnus had been in the Throneroom when Prospero had fallen, working on the Emperor's great device. The blow hit the wards placed upon the Webway gate with a force worthy of gods, and shattered them, exhausting all of its energy in the process. Their path unbarred, the million millions daemons that had waited on the other side poured through. At once, the Emperor, Magnus and the Custodians had begun a fight that would last the entirety of the Heresy.

Horus and Perturabo were left in charge of the defence of Terra, while Ahriman directed the efforts of the Thousand Sons. As the Emperor and the Crimson King battled underground, some lesser creatures of the Warp also found their way through the damaged wards of Terra, no longer forced back by the Emperor's psychic aura, for He was wholly focused on preventing the greater incursion. The sons of Magnus walked the hive-cities of the Throneworld, finding rogue psykers, mutants, and secret worshippers of the Ruinous Powers who, for the first time in more than two hundred years, suddenly found their prayers answered once more. Several times, the Thousand Sons battled against daemonhosts, protecting the people of Terra from threats that they had long believed to be no more than ancient myths. Despite the sons of Magnus' best efforts to hide the truth, rumors soon began to spread, and turned into a hundred legends that persist to this day, of beasts of darkness and the crimson warriors who battled them during the darkest of days.

The years of the Roboutian Heresy passed, with the Arch-Traitor drawing ever closer. During these days, amidst the endless tide of daemons that he fought side by side with his father, Magnus received a terrible vision, intended as a taunt from the Dark God Tzeentch. The Crimson King saw what had become of his brother, Lion El'Jonson, and wept at the fate of the knight-lord of Caliban. Taking a short time away from the fight, Magnus sent a message through the Warp to Luther, who even now awaited his liege's return on Caliban, unaware of his treachery. This warning would prove instrumental in denying the Traitor Legions a considerable asset, though it would cost many loyal lives and the First Legion's homeworld.

Finally, the Traitor Legions and their allies, both mortal and daemonic, reached the Sol System, and the final battle of the Heresy began in earnest. After Guilliman's armies had breached through the orbital defenses of Terra, the forces of Chaos flooded the planet, and the Thousand Sons stood upon the walls of the Imperial Palace. At their side were the Sons of Horus, the Iron Warriors, and the Death Guards, and together they wreaked terrible destruction upon the enemies of the Imperium.

Then the Dark Angels' Sorcerers gathered in dread circles of their own, and cast evil spells upon the defenders of the Imperial Palace. Entire Companies of Astartes were lost to grotesque mutations and Warp-fire, and the Thousand Sons were forced to withdraw many of their Librarians from the walls so that they could focus their minds on countering the sorcery of the First Legion. Only those of the sons of Magnus with little psychic power or an inability to mind-link remained on the walls. Among them was Amon, the former Equerry of Magnus, who had neared death at the Wolf King's hands, but had been reborn in the form of a Dreadnought.

Amon, Equerry of Magnus

In his youth, Amon was haunted by dreams of Tizca in flames. Only when Magnus arrived on Prospero did the nightmares abate, and Amon believed that the Crimson King's presence had somehow averted the terrible vision.

When the Emperor came to Prospero, Amon was a grown man, far too old to become a Space Marine. At Magnus' demand, he became one of the so-called "false Astartes", akin to Luther of the Dark Angels. He was given extensive genetic modifications, and access to the best equipment the Imperium could provide. Combined with his precognitive abilities, this made him more than able to fight alongside the rest of the Fifteenth Legion, becoming the Magister Templi of the Corvidae. For many years, he led this section of the Thousand Sons to war, before leaving command to Ahzek Ahriman and becoming the Primarch's Equerry.

After his wounds at the hands of Leman Russ at the Council of Nikaea, Amon was healed by his Primarch. But the power of the Cyclops, diminished by the constant warding of his sons' souls, was not enough to fully repair the damage wrought by the Wolf King's fury, and Amon had to be interred in a Dreadnought. He returned with his father to Terra, where he lent his wisdom to his brethren in between his moments of rest. When Khayon returned with news of Prospero's fate, Amon found his youthful vision had come true, and vowed revenge on the scions of Chaos. Disregarding slumber from that point on, he fought during the Heresy to help keep Terra safe, and faced the Traitor Legions on the walls of the Imperial Palace during the Siege. There he slew many traitors before being finally killed by Ferrus Manus when attempting to enter the Cavea Ferrum, in the last hours of the Heresy.

For days, the Thousand Sons psychically battled the Dark Angels, under the direction of their First Captain Ahriman. One the fifth week of the Siege, however, the walls of the Palace were breached by a warband of the Sixth Legion, led by the Rune Priest Ohthere Wyrdmake and the champion Bjorn Fell-Handed. Ahriman duelled with the Rune Priest, and destroyed his opponent's mind by revealing to him the truth of what he and his Legion had become : murderers of innocents, who justified their paranoia with self-delusions and false righteousness born of fear and bloodthirst. Wyrdmake's very soul was destroyed by the power of the First Captain, yet Ahriman would have died at Bjorn's claws had it not been for the intervention of Lucius the Reborn. The undying warrior of the Emperor's Children stopped the Space Wolf champion, and his mere presence forced the Wolves into a retreat.

Yet the damage had been done. For a moment, the circle of the Thousand Sons had been disturbed, and the Dark Angels had capitalized on the opportunity their allies of the Sixth Legion had bought them. Ahriman had to use all of his power and will to prevent the entire outer wall from collapsing under their psychic assault, and the strain was such that Phosis T'kar, Magister Templi of the Raptora Cult, burned himself to a husk to repeal the advantage the foul Sorcerers had gained.

Mere hours after Phosis' death, Horus and Sanguinius duelled at the Eternity Gate, and the Warmaster fell under the fangs of the Fallen Angel. The Primarch of the Ninth Legion was reborn as an avatar of the Dark Prince, Slaanesh, and the Blood Angels finally focused their attention on the Palace instead of the Terran population. Only the arrival of the Night Lords and the Emperor's Children, emerging from their own path through the Webway, prevented the Traitor Legions from overwhelming the walls.

When the Mournival destroyed Sanguinius' physical incarnation, the tide clearly turned against the traitors for the first time since they had landed on Terra. They could still win, for they held superior numbers, even with the Blood Angels incapacitated by Sanguinius' fall. But the Warp was roiling with the coming of the Twelfth and Seventeenth Legions, returning from the Ruinstorm with vengeance in their hearts. When they arrived, there would be no more hope of victory for the traitor armada. His back to the wall, Guilliman was forced to gamble everything on one last stratagem.

The Arch-Traitor himself led one massive assault on the gates of the Imperial Palace, accompanied by three of his brothers. The wards the Thousand Sons had raised and the walls the Iron Warriors had built were equally shattered by the advance of the four Traitor Primarchs, while the loyal Space Marines who stood against them were obliterated, barely slowing their advance.

Three Traitor Primarchs entered the Cavea Ferrum : Roboute Guilliman, Rogal Dorn, and Lion El'Jonson. Of the three, only El'Jonson had shed his mortality to become an immortal prince of the Warp, but he was far from being at his peak strength. At Caliban, his battle against his foster father Luther had ended badly for the Lion, for though he had been victorious, his chest bled forever from a wound that was as physical as it was metaphorical. Yet still, as a Daemon Prince of Tzeentch, his sorcerous power was considerable, and should he fight the Emperor alongside Guilliman, then the Master of Mankind couldn't hope to prevail.

So it was that Magnus deployed his powers across the labyrinth, combining his psychic abilities with the non-euclidian geometries of Perturabo's constructions to separate each of the Traitor Primarchs and direct them to their own individual battles. While Perturabo faced his old rival Dorn and the Emperor fought against the Arch-Traitor, it fell to Magnus to banish the fallen master of the First Legion. Meanwhile, the Emperor's greatest and most devoted servant, Malcador the Sigillite, sat upon the Golden Throne, keeping the daemonic hordes at bay through sheer psychic power.

The duel between Magnus and Lion El'Jonson was sorcerous as well as physical. The Crimson King was exhausted by the years of endless battles against the daemonic legions, but the Daemon Primarch was also severely weakened by the wound Luther had dealt him. In the end, thanks to the old knight's dying gift, Magnus was able to unravel the threads that linked Lion El'Jonson to the mortal plane, and cast his shrieking spirit into the Aether, to the foot of the Great Deceiver's throne.

After his victory, Magnus sensed an event of momentous import taking place in the center of the Cavea Ferrum, right where it had been planned for the Emperor to confront Guilliman. He knew then that Guilliman had fallen, and felt the traitors run from the Throneworld – but he also sensed something else. Rushing through the twisted corridors, Magnus beheld a vision of absolute despair : his father was dying, and a scarred and grim revenant that the Crimson King only barely recognised as Fulgrim stood guard over Him. Beyond them, Malcador was gone from the Golden Throne, nothing but a pile of ashes remaining of the First Lord of Terra. Already, the daemonic hordes, temporarily cast back by the defeat of their champion Guilliman, were gathering anew.

With no time to find another way, Magnus dragged his father's body toward the Throne, while Perturabo, newly arrived to the scene of devastation, worked the ancient mechanisms. Never before had the Iron Lord laid eyes upon the wondrous machine, yet he understood its workings at a glance, and together, the Cyclops and his brother put the Emperor upon the Golden Throne, activating the stasis field and other preservation devices that would keep Him alive forevermore and enable Him to hold back the tide of Chaos.

The Heresy was over, but the Emperor was lost to Mankind. And with Him, so was lost His dream of a Humanity free from the Warp, and His plan to make that glorious vision reality.

Post-Heresy : The War of Fate

'My sons cry out for vengeance, and seek the blood of the Wolves. They speak of Fenris, and crave its destruction. Their nights are haunted with the screams of our murdered world, and they know no peace. In time, I shall lead them there, but there is much more important work to do first. My brothers have broken the galaxy apart, sundering the Veil, and the foulness of the Warp seeps into reality through a thousand wounds. All must be found, all must be closed. That is my task, and as long as it is not complete, I cannot allow my sons justice, nor myself the luxury of grief, or all that is shall become tainted by the Ruinous Powers. But I fear the cost to my sons.

Of all of them, it is for Iskandar that I fear the most. His rage has darkened his thoughts, and the hatred he feels for Russ' get grows with each passing week. He recognizes this and tries to contain it with meditation, but it is not enough. His dreams are haunted by wolves, and they press on the minds of those nearby. He thirsts for the death of the Sixth Legion, and all traitors with them. It hurts to see him like this, and yet, I cannot help but think that perhaps, this hatred makes him better suited to the new galaxy than any other of my sons, who for all their desire of justice are still consumed by sorrow.

For as I peer into the future, I see only darkness, and war unending.'
From the writings of Primarch Magnus, after the Siege of Terra

Although the Traitor Legions had been broken at Terra, the powers they had unleashed upon the galaxy during the Heresy cared little for the fall of Guilliman. Dozens of Warp Rifts had been opened, either deliberately or as a result of planet-wide carnages, and daemonic incursions raged unchecked on hundreds of world. Greatest of these wounds in reality was the rift of Pandorax, where the Iron Hands had first been dragged into damnation by the schemes of Nurgle, Chaos God of Decay. On the cursed daemon world of Pythos was a tear in the fabric of the universe through which thousands of daemons passed daily, forming a host that could very well grow until it threatened the recovering Imperium itself.

Even from Terra, Magnus could feel the taint of the rift, and the threat it represented. While other Legions hunted the traitors across the galaxy, Magnus gathered what resources he could to attack Pythos and close the rift. He found an unlikely ally in the person of his brother Mortarion, who knew also very well the danger posed by the daemonic portal. Together, the two Primarchs were able to draw far more military forces to their cause, and came to the Pandorax system with an armada worthy of the Great Crusade.

Yet despite all that might, the Battle of Pythos was to see the fall of Mortarion, under the claws of Daemon Primarch Vulkan, returned triumphant from the War of the Dragon, at the other side of the galaxy. Enraged by his brother's death, but determined to finish what they had started, Magnus managed to seal the Pythos gateway into the Warp, banishing the remaining daemonic hosts. Hundreds of Thousand Sons worked together to create the wards of the Damnation Cache over the location of the rift, to make sure that it would never be opened again.

After the Battle of Pythos, the Scouring continued for the Thousand Sons. Scattered across the stars, they fought to seal the other rifts opened during the Heresy, until the time that Magnus decreed that their task was complete. By that point, more than a century had passed, and the Thousand Sons still hungered for revenge. It was time, declared the Crimson King. At long last, the Fifteenth Legion would bring just retribution upon the treacherous Space Wolves. The time had come for them to go to Fenris.

The Battle of the Fang remained in the annals of the Thousand Sons as a great victory, as it did in those of their allies the Sons of Horus and the Imperial Regiments who were present. But in truth, it was a bitter victory, that came at great cost and did not prove to be the final destruction of the Space Wolves that the sons of Magnus had hoped for. With the intervention of Bjorn Fell-Handed at the last moment, many warriors of the Vlka Fenryka escaped. Fenris itself, however, was destroyed even more completely that Prospero had been, ripped apart by its own inner energies and the Warp Storm unleashed by the Fell-Handed's final, spiteful act of firing on the Fang with his ships.

In time, the Battle of the Fang would prove to be no more than another event in the long series of battles the Fifteenth and Sixth Legions would wage against each other over the millenia. This long-standing hatred would erupt once more a thousand years later, and end up costing much more to the Thousand Sons that they were prepared to give.

In the two-hundred and seventy-fourth year of the thirty-second millennium, a Black Crusade was declared against the Prosperine Dominion by the Chaos Lord Vaer Greyloc. Once, Greyloc had been the commander of the Twelfth Great Company, but his hold over his men had weakened since the Battle of the Fang, and his Great Company had fractured in several warbands. Yet Greyloc had not let this discourage him, and he had spent ten centuries plotting, gathering allies, and striking infernal bargains – all in the name of vengeance, and of finishing what the Space Wolves had started at Prospero. Greyloc's Black Crusade sought to purge the entire Dominion from human life, to destroy the Thousand Sons' fortresses and slay the Crimson King.

Ultimately, Greyloc was defeated, and slain by First Captain Ahriman. But during the final battle of the Black Crusade, the Legion's flagship, the Photep, was boarded while Magnus was on board. Leading the boarders was one of the Chaos Lord's allies, a powerful Lord of Change, who confronted Magnus and cast a powerful curse upon the Primarch before withdrawing and abandoning the Dark Angels contingent that had accompanied it aboard the vessel. The curse expelled Magnus' spirit from his body and into the Warp, where it remains to this day, engaged in an eternal conflict against the servants of Tzeentch. The Thousand Sons evacuated their Primarch's body from the ship just before the Dark Angels sabotaged its Warp drive, causing it to detonate. It is unknown whether the sons of the Lion knew that they were going to their doom when they boarded the Photep – doubtlessly they sought to avenge their Primarch's defeat during the Siege, perhaps not caring for the cost to themselves.

'I see it … my sons, I see it ! I see the Emperor's light, returning to the galaxy in its darkest hour … I see the fire of hope kindled anew, and the broken dreams reforged in the fires of war !'
Magnus' last words before succumbing to the curse and falling into a coma.

The Thousand Sons have vowed to find the daemon responsible and extract from it the truth of their Primarch's fate, and how to remedy to it. Over the centuries, this quest has been unsuccessful, but the sons of Magnus have learned much about the Lord of Change, including the name it uses the most : Sarthorael the Ever-Watcher, one of the most powerful Greater Daemons of Tzeentch. They have clashed with the creature several times, but so far, Sarthorael has always managed to either slay all its enemies or escape.

Soon after Magnus' spirit was lost to the vagaries of the Warp, the Thousand Sons began to suffer from a Legion-wide plague of mutations that immediately brought to the minds of the veterans the horrors they had endured before their Primarch was found. The flesh-change, kept at bay by Magnus for hundreds of years, had returned. The new Legion Master, Ahriman, threw himself into the search for a cure, studying his father's notes in the Book of Magnus, seeking to replicate the Primarch's feat. After years of research, during which the numbers of the Fifteenth Legion continued to decrease increasingly quickly, he believed that he had found a way.

Ahriman called for a gathering of the entire Legion on an uninhabited world within the Prosperine Dominion. There, together with several dozens of Librarians, he cast a spell called the Rubric, that he hoped would recreate the psychic warding Magnus had once raised around his sons.

None but the Thousand Sons were present on that nameless world, and they never spoke of what exactly happened after the ritual was cast. But where thousands of Legionaries had gathered, barely more than a thousand returned. These warriors were free of the flesh-change, but according to them, all the others – those whose psychic strength had been too weak to endure the Rubric's power – were dead. Ever since that day, the recruitment of new Thousand Sons has slowed to a crawl when compared to other Legions, despite the Fifteenth Legion having access to their Primarch's body and a great number of worlds from which to claim aspirants. Their numbers have slowly eroded over the millenia, and many Chaos Lords and other heretics have claimed that their extinction is but a matter of time.

Soon after the Rubric was cast, Ahriman disappeared, leaving the Thousand Sons leaderless. There are many claims that the former Legion Master wanders the Webway, though what his purpose is varies according to rumors. Some pretend that he seeks one of the missing Primarchs, others that he is looking for a way to return his father's spirit to his body, yet more that whatever his reason for entering the Webway, he is now running for his soul from a host of daemons. Most, though, especially among the Thousand Sons themselves, believe that he searches for a way to perfect the Rubric.

He marched in darkness, his path light only by points of light that seemed at once infinitely far and within his hand's reach. Corridors left the path he walked, some of them leading to blackness similar to the one he now crossed, others leading to openings to worlds he did not know. He felt the temptation to just cross any of the openings, to return to the material realm. But he continued walking. This was his penitence, and his absolution. His hands were red with his Legion's blood, and he would make things right. Perhaps it was his pride speaking – the same pride that had led him to believe he could emulate his father's work. Perhaps it was desperation, the urge to flee from his crime rather than face it.

In the end, it did not matter. The Exile kept walking, letting his mind follow the impossibly alien designs of the labyrinth, searching for its center. He was chasing a myth and he knew it – even those whose kin controlled it regarded it as little more than an ancient legend. But the Exile had seen myths before. He had been part of legend, witnessed and shaped history. This myth, the story of the Black Library, was the only hope he had. And so he walked, uncaring of how many centuries it would take.

Motion before him drew his attention away from his half-conscious reverie, and he raised his staff before him, ready to defend himself. Many times already he had been attacked, by beasts seeking to feast on his body and by creatures sent by enemies of his Legion.

But this newcomer was neither of these things. It was a silhouette of shadows, wearing a mask that was at once beautiful and terrifying on some primal level of the Exile's soul.

The silhouette motioned with one finger for the Exile to follow it, and walked into another corridor of the Webway.

Ahriman followed.

With the slow diminishing of the Fifteenth Legion and their protection of psykers and other individuals connected to the Warp, the Imperium slowly became more intolerant of the Warp-touched. Fear and hatred of the mutant grew, and the Sisters of Silence, already decimated during the Siege of Terra, suffered for it. With the recruitment of pariah becoming more and more difficult, and the Lords of Terra's repeated moves against them in order to gain political clout, the Order became a shadow of what it once was. Today, the Sisters of Silence still exist, but they are reduced to a handful of monasteries scattered across the Imperium, where they keep away from prying eyes. The Inquisition, especially the Ordo Malleus, protects these last outposts, for the Sisters of Silence are often a useful tool for the Inquisitors in their endless battles against daemons.

Also following from the Fifteenth Legion's weakening, ignorance and superstition have also been on the rise. The Inquisition's constant and ruthless suppression of all knowledge of the daemonic, combined with the Thousand Sons' no longer being able to keep all of their records alive in memory, has caused the Imperium's collective knowledge of the Great Enemy to fade. In the latest centuries, many Inquisitors have recognized the threat this poses, but all who have tried to do something about it have ended up walking the path of the Radical, corrupted by the knowledge they managed to acquire, and were hunted down by their colleagues, only reinforcing the Inquisition's belief in the suppression of such knowledge in the vicious circle.

Worst of all, perhaps, to the Thousand Sons, is how the distrust of the psykers is slowly spread to the other loyal Legions. After all, recruits are taken from human worlds, and all the psycho-conditioning they go through does not fully erase the beliefs they had when they were mortal. Over the years, the Fifteenth Legion has grown more and more isolated, for while the Librarians of other Legions can at least claim the connection of blood with their doubting brethren, the Thousand Sons are further removed. For now, this has had no other consequence that the sons of Magnus suffering from isolation, but the potential for some catastrophic misunderstanding remains.

And while the Imperium grows weaker with every passing millennium, more and more threats continue to appear. During the forty-first millennium, the Seers of the Corvidae foretold of a great power rising throughout the galaxy, awakening from an aeon-long slumber. Soon after this wave of visions, entire Imperial worlds all across the galaxy suddenly fell silent, without so much as a single astropathic cry for help. The Thousand Sons have marshalled in strength unseen for thousands of years in order to investigate this new threat to Mankind's rightful dominion over the stars, accompanied by agents from all three Ordos and contingents of the Adeptus Mechanicus.

The Thousand Sons and the Grey Knights

At first glance, the Fifteenth Legion and the sons of Titan might appear very similar. Both are groups of psychic Astartes, their numbers are roughly equal, and many of the first Grey Knights chosen by Malcador the Sigillite were taken from the ranks of the Fifteenth Legion.. However, there are many key differences between the two.

While the Grey Knights' aspirants are entirely remade during their Ascension – their past identity literally destroyed and wiped out – the Thousand Sons are far less intensive in their training. A son of Magnus is a teacher, and needs to keep an open, if well-defended mind.

And while the Grey Knights are unleashed against the daemonic threat when they become the only option, the Thousand Sons wage the War of Fate on the Imperium's behest continuously. Their Seers battle the Dark Angels' oracles, the Eldar farseers, and all other kinds of prophets that would use their abilities against Mankind. They are not beholden to the Inquisition, but fight the wars that need to be fought, not for the present of the Imperium, but for its future.

As for the other Thousand Sons, they fight alongside the Imperial armies without keeping their existence a secret. The coming of the Fifteenth Legion is a source of both relief and dread, for while their power is great, their arrival indicates that the situation is dire indeed. Meanwhile, the Grey Knights' very existence is kept a secret from the Imperial population and the Imperium's enemies alike, meaning that those who fight at their side and witness their prowess are usually purged at the battle's end – often by the very hands of those champions who delivered them from the daemonic threat.

Organization

There is no true chain of command among the Thousand Sons, no Legion Master to replace the Primarch. Officially, Magnus still leads the Legion, his sons waiting for his awakening. The Thousand Sons take such things very seriously, and when two sons of Magnus meet for the first time, they will begin a mental communion, at the end of which one of the two will have been declared as the other's superior. This unseen hierarchy is decided by an ensemble of factors, such as age, psychic power, and reputation.

The bond of master to disciple is also very important. New Legionaries are assigned to older ones of the same Cult, who will guide them in their progress through the Arts and share with them their experience of the Imperium's many enemies. Even after an apprentice has been released from his master's teachings, he still honors his former master, though it is frequent for the student to surpass the teacher – and indeed, encouraged, as it means the strengthening of the Legion as a whole.

Though scattered, the Thousand Sons keep in contact with each other. They use unique cyphers to send messages through the Imperium's network of astropaths, and some of the most powerful Athanaeans are capable of communicating with each other from different star systems. This enables the Fifteenth Legion to coordinate its actions on a galactic scale, despite the absence of true hierarchy. The Legion decides its action by coming to a consensus, taking advantage of the fact that their discussions occur literally at the speed of thought.

The Sanctum of Magnus

When the Legion's flagship, the Photep, was destroyed in the last battles of the Scouring, parts of it were salvaged, including the Primarch's war chamber. A pyramid of Prosperine crystal, the Sanctum offered a magnificent view of the stars. Its survival of the Photep's destruction is viewed by many as a miracle, and it was dragged to the orbit of Prospero, where the Thousand Sons still use it as a gathering place.

Within the Sanctum is a great spiral, at the center of which stood Magnus when he directed his Legion's war councils, each Captain assigned a place on the spiral depending on his current status among the Thousand Sons. Nowadays, when a group of Thousand Sons meet in the Sanctum, their place on the spiral is determined by drawing cards of psychically sensitive crystal, and the results are often interpreted by the Seers of the Corvidae, if any is present.

Combat doctrine

The Seers of the Corvidae

Of the five Cults of the Thousand Sons, the Corvidae are the most famous and influential. Capable of peering into the madness of the Warp without losing their minds, these prophets are capable of gleaning knowledge of what was, what is, and what might be. It is thanks to the Corvidae that we know most of what we do about the Traitor Legions' dealings in the Eye of Terror, for they are some of the few who can look into that abyss of perdition without loosing their souls to the unholy creatures that dwell there.

The Legionaries of the Corvidae are often the leaders of their cabals, or at least influential advisers. They guide their forces toward battles yet to erupt, so that the Thousand Sons might arrive in time. They use many different ways to divine the future : some use the Emperor's Tarot as a focus of their own power, while others make use of psychically sensitive crystals and other simply immerse their minds into the Warp while their bodies sit in circles of warding.

While theirs is the smallest of all Space Marines Legions, loyal or otherwise, the Thousand Sons are the most powerful on an individual basis. Instead of Chapters or Companies, the Fifteenth Legion is divided in small groups, rarely as large as any other Legion's squad, called cabals. These cabals wander the Imperium, bringing their power to bear against the enemies of Man. They either attach themselves to military forces, travelling aboard their ships, or command vessels of their own, though the Thousand Sons' fleet is far smaller than is common for a Space Marine Legion. Their ships are also of inferior size, and are generally guided through the Warp by a Thousand Son rather than a Librarian. This allows for much faster journeys through the galaxy, enabling the Thousand Sons to reach their chosen battlefields ahead of any other Imperial reinforcement.

Each warrior of the Fifteenth Legion belongs to one of the Cults that were created by Magnus, specializing his abilities into one school of psychic powers. While it is common for them to master a few skills in the other schools, they remain mainly focused on the one chosen during their initiation. Each cabal is generally accompanied by a hundred or so soldiers from the Spireguard, elite soldiers picked across the Dominion in replacement for the standard tithe of Imperial Guard Regiments. The exact number of this accompanying force can vary greatly, from a few dozen to hundreds of soldiers and accompanying heavy machines.

The Spireguard

Across the Prosperine Dominion, the memory of the Spireguard lives on. The legends of how these brave warriors fought to the end to defend their homeworld from barbarians and monsters have inspired many young men and women to join their new incarnations over the course of millenia. Selected from the militia and PDF of the Dominion, the Spireguards are trained in fighting side by side with the Thousand Sons, sworn to guard them with their lives if necessary. Because the Thousand Sons are often forced to battle mentally against other foes, their bodies require protection, and unlike the Librarians of other Legions, they have no non-psychic brethren to guard them.

The Spireguards were the crimson fatigues of their ancestors, and bear the emblem of Prospero upon their shoulder. Drilled to perfection over hundreds of simulated battles, they are capable of adapting to almost every situation, placing the safety of their Legionary masters at the forefront of their minds. They are equipped with the best weapons and armor the Prosperine Dominion can produce, and even have psykers among their number, though they are more an alternative mean of communication than instruments of war.

The total number of the Spireguard is in the millions, which has led to some uncomfortable questions over the centuries. Ever since the terrible events of the Roboutian Heresy, Astartes are not supposed to have command of human troops, yet the Thousand Sons clearly require such assistance to make the most of their unique abilities, and lack the numbers to field enough Legionaries to accomplish the objectives ordinarily assigned to Astartes. So far, a tacit understanding between the Fifteenth Legion and the Lords of Terra has kept the situation from degenerating, but there are still many Inquisitors, consumed by paranoia, who wish for the Thousand Sons to be called on account.

In battle, the Thousand Sons are formidable foes. Each is a psyker lord, easily the equal of the greatest Librarians of other Legions. They generally target the enemy commanders and their own psykers, but one the rare occasions when they let loose their might on common forces, the results are devastating. Entire armies can be broken in minutes by a cabal working in synergy, and titanic war-engines can be brought low. That is not to say that the Thousand Sons are invincible, however : there are Chaos Sorcerers who can match them, and the Eldar warlocks are gifted with even great knowledge of the Sea of Souls, dating back to the glory days of their fallen empire. The disciples of Khorne too are often shielded from the Thousand Sons' powers, and there are many other threats that cannot be matched with psychic power alone. In these cases, the sons of Magnus remember the lesson their gene-sire learned when he battled the Psychneuein-Prime, and rely on their bolters and blades, at which they are just as adept as all Astartes are.

Homeworld

Prospero, adopted homeworld of the Primarch Magnus, is a tomb, haunted by vengeful ghosts. The unholy ritual performed by the Rune Priests in the hope of destroying the entire Fifteenth Legion has bound the souls of those who died during the Burning to the place of their demise. Billions of humans and Space Marines walk the ruins of Tizca, the City of Light, and the other destroyed settlements. It is rumoured that these ghosts, during the Heresy, helped Mortarion escape the White Scars during the Second Battle of Prospero.

Yet the Thousand Sons have not abandoned Prospero – far from it. The world is bathed in psychic significance, and home to a million dark secrets. Over the centuries, many Chaos Sorcerers have sought to harness the power of the Planet of Dust to their own ends. Though most of these fools are annihilated by the Prosperine shades the moment they land on the world, the sons of Magnus have taken precautions. Prospero is guarded by a ring of orbital fortresses, gifted to the Fifteenth Legion by Perturabo himself. These stations are capable of fighting off an entire Chaos fleet long enough for reinforcements to arrive from nearby Imperial Garrison Worlds.

Now, the Legion's headquarters – such as they are – stand on the world of Terathalion. During the Great Crusade, Terathalion was a library-world, a place where the knowledge found by the forces of the Emperor was stored, catalogued, and studied. It was part of the Prosperine Dominion, but its importance was minor at best, and it was forgotten by traitors and loyalists alike during the Heresy. When the Thousand Sons returned after the Scouring, they rejoiced to find that at least a part of their great work had endured, and vowed to protect it forevermore. Now, Terathalion is home to the Legion's main fortress and training center, as well as the sanctuary in which lies Magnus' body, guarded by the most potent defenses and wards of the Fifteenth Legion.

The human survivors of Prospero, who had gone through the destruction of their world and the horrors of the Siege, resettled on Terathalion, and tried to go on with their lives. Many were driven mad by what they had witnessed, but their descendants still live on that world to this day, forming the population from which the renowned Spire Guards are selected.

The Thousand Sons are determined that the fate of Prospero will never befall any other of their worlds. Terathalion, like all worlds of the Dominion, is defended by the greatest orbital defences a Space Marine Legion can build, and its cities are as much fortresses as they are libraries. This, and ten thousand years of attempted raids by Space Wolves warlords, has caused the population of the Dominion to develop a paranoid streak, always looking at the sky for the first sign of attack.

The Archives of Shame

Among the thousands of great libraries of the Prosperine Dominion, one is closed to all but the highest-ranking Inquisitors of the Ordo Malleus and lords of the Space Marine Legions. It is located atop a great tower, in the middle of a fortress on the surface of a nameless world, without even an atmosphere of its own. The archives can only be acceded through an elevator that carries only one person at a time, and can be dropped at any moment if the bound psykers of the fortress detect the slightest fluctuation in the occupant's soul. There are contained all the grimoires, scrolls, dataslates, and a hundred more forms of knowledge, that the Legion has gathered about Chaos.

The name of the archives come from the fact that they effectively defy the command of both Magnus and the Emperor that the Thousand Sons remain as far from the Ruinous Powers as possible. But that decree was made before the Roboutian Heresy, before the Burning of Prospero, and most important of all, before the Scouring and Magnus' fall. Without the guidance of their Primarch, the Thousand Sons believe that they need to know as much as possible about their foes without risking their souls, and have amassed a truly staggering amount of information over the millenia. At the same time, they also recognize that it is a thin line they are walking, and that any mistake might very well send them into damnation – hence the name of the archive, as a constant reminder to all who walk within its walls that they act in defiance of the Emperor's will, no matter how noble their intentions or pure their souls.

Beliefs

'Knowledge is power; guard it well.'

Motto of the Thousand Sons

During the Great Crusade, the Thousand Sons were seekers of knowledge, who hoped to usher in a golden age for all of Mankind. Now, they have become bitter at all that was lost in Guilliman's Heresy and Russ' madness. Each of them knows of the glories of the Great Crusade, and the promises that came undone when the Arch-Traitor turned from the Emperor's light. The existing Imperium, for all that it has endured ten thousand years, is a wretched reflection of what they believe it could – should – have been. Instead of the Great Crusade's illumination, Mankind now recoils from knowledge in fear of the heresy it might bring, and the Lords of Terra have become tyrants rather than leaders.

Furthermore, while the human denizens of the Imperium can find solace in the Imperial Creed and the Ecclesiarchy's claims of the God-Emperor's unchallengeable power, and warriors of the other Legions only need worry about the foes they face, the sons of Magnus know just how precarious Mankind's place in the galaxy truly is. With every day, they sense the Warp growing darker as the servants of the Dark Gods grow bolder, and other threats rise to deny Humanity its rightful rule over the stars.

Yet the Thousand Sons have not given up hope. Despite the many horrors they face, despite the encroaching darkness, they still cling to their Primarch's last words. They believe, as many do among the Legions, that a time will come when the Emperor will return from His deathless sleep, and lead the Imperium once more in person as well as in spirit. In the meantime, they fight to preserve Mankind, to keep the empire strong, to save even one more soul from the Dark Gods' ravenous grasp. Those among them who do not believe so fight out of defiance, to honor the memory of all those who came before them. Some also fight solely driven by the burning need to avenge those long dead – they are known as the Heralds of Prospero, and are feared even amongst their own Legion.

The Heralds of Prospero

Sometimes, by some quirk of genetic memory or a psychic affinity, a Thousand Son will be haunted by visions of the Legion's destroyed homeworld. Compelled to make a pilgrimage on Prospero itself, these tormented souls return from their journey transformed. Ghosts cling to their steps, sharing their thoughts and driving them to slaying all traitors. Their aura is filled with the screams of the dying and the curses of the dead, and none can stand their presence for long without being forced to flee, unable to bear the tormented choir any longer.

Yet for all the darkness attached to them, the Heralds are not mad, nor are they corrupted. Indeed, their full awareness of what they have become and what is happening to them is perhaps their greatest curse. They wander the galaxy endlessly, with only the ghosts of Prospero at their side, seeking the blood of all who turned their back on the Golden Throne. Most of all, they seek the Space Wolves, those who came to the Planet of Dust ten thousand years ago and razed it to the ground. Using ships that they lead through the Warp themselves, guided by the shades of the long since dead, they journey from one war-torn world to another.

In battle, a Herald of Prospero is a terrifying sight. They do not fight alongside any Imperial forces, and in most cases, the first warning a Guard Commander has that one of them has arrived on the planet is when they reveal themselves at the heart of the fight, slaughtering heretics and clamouring for their Chaos Marine champions to confront them. In the midst of battle, the Heralds call upon the shades of Prospero, giving them form into ghostly shapes that drain the life of heretics and dramatically increase the psychic power of their summoner. Stories abound among the Imperial Guards of these vengeful sons of Magnus and the shadowy armies that march in their wake, and the Traitor Legions themselves hold a fearful respect for their power.

When one of their number goes to Prospero to become a Herald, his brothers mourn him as if he were fallen in battle, and his name is inscribed on the Legion's rolls of honor. There is no return for these warriors, and even the peace of the grave is denied to them. When a Herald of Prospero falls, his spirit does not dissolve back into the Aether, nor can it be claimed by any daemon, no matter how vengeful. Instead, it is dragged back to Prospero itself, where it rejoins the legions of ghostly warriors that wander the ruins of the world. There, it can be bound to another Herald when they make their own pilgrimage to Prospero, starting the whole cycle anew.

The Chaplains of the Fifteenth Legion have to take even greater care of their duties than those of other Legions, for the powers of the Thousand Sons also make them choice targets for the corruption of Chaos. While all those who survive the trials to become a son of Magnus possess tremendous willpower, their souls are constantly threatened, as three of the four Chaos Gods seek to engineer their downfall. Chaplains travel from one group of Thousand Sons to the next, or keep watch over sanctums scattered across the galaxy, where the sons of Magnus can come and obtain the spiritual advice they crave after long years of war.

Only Khorne, the Dark God of Slaughter, cares nothing for the sons of the Cyclops – the Blood God dislikes sorcery, and the Thousand Sons' mastery of the Warp, despite being untouched by the taint of Ruin, is seen as such by the brutish daemonic entity. The only known exception is the infamous Gabriel Angelos, known to the Imperium as the Blood Raven, and to the Thousand Sons by many names, none of which flattering.

Gabriel Angelos, the Blood Raven

Over the course of ten thousand years, very few Thousand Sons have ever succumbed to the temptations of Chaos. Each time it happened was a dark day for the Imperium, for the sons of Magnus wield power greater than the warriors of any other Legions, and the hunt for such renegades was as swift as it was merciless. Yet one traitor eludes judgement still, and has done so for nearly five centuries.

Born on the world of Cyrene, Gabriel Angelos was identified as a latent psyker by a group of Thousand Sons led by Azariah Kyras. Kyras sensed the potential for greatness in the young boy, and took him into the Fifteenth Legion. During his training in the Prosperine Dominion, it was revealed that Gabriel had only minimal psychic potential, mostly in the field of precognition, and his control over it was mostly instinctual, allowing him to anticipate his foes' movements and counter them. When his training was complete, there was much incertitude about whether or not he should undergo the final trials – none doubted his bravery or his skills, but the Apothecaries were unsure that he had any hope at all of surviving the Rubric.

At his own insistence, Gabriel was finally put through the trials, and surprised all by surviving them, though his psychic powers didn't receive the boost that normally accompanies the Rubric. He then joined with another group of Thousand Sons, and for four decades, did the Emperor's work across a score of worlds, earning much honor despite his lack of the Legion's characteristic powers.

But his fate turned when he and his battle-brothers returned to Cyrene, hoping to find new recruits to fill the ever-diminishing ranks of the Fifteenth Legion. Instead, they found the planet in the throes of rebellion against the Imperium. More shockingly, this rebellion was led by Gabriel's own human father, who had grown bitter against the Imperium after his son was taken from him. The local garrison had already been either turned or butchered, and the Thousand Sons' cabal was the only Imperial force nearby. The six sons of Magnus unleashed their powers upon the rebels, slaying thousands, seeking to break their morale and force them to scatter until the summoned reinforcements arrived.

Amidst the confusion, Gabriel left his brothers, seeking to confront his father in person, hoping to stop the rebellion at its source. What exactly happened when he finally met him is unknown, but Esmond Angelos, former Imperial Guard turned traitor to the Golden Throne, died that day, at the hands of his own transhuman son. His death broke the rebellion in multiple factions, and the pressure on the Thousand Sons abeted. Yet when Gabriel returned to his brothers, they immediately sensed that something had gone horribly wrong, and they were proven right when Gabriel turned on them, slaying them all, seemingly immune to their psychic powers. The last of them to die, a warrior named Isador Akios, managed to send an astropathic message warning of his brother's betrayal before he was slain.

Gabriel vanished from Cyrene, leaving in his wake the fractured rebellion, that quickly turned on itself. Before Imperial forces could arrive, the bloodshed had escalated to the point that daemons of Khorne had begun to appear on the planet, and the Inquisition condemned Cyrene to Exterminatus, even as its agents picked up Isador's dying message and the terrible news that another son of the Cyclops had fallen to darkness.

When he was informed of this turn of events, Azariah Kyras vowed to bring his wayward pupil to justice. For half a millennium, the old Thousand Son has sought to fulfill that oath, hunting Gabriel Angelos across the width and breadth of the galaxy, following the trail of carnage the renegade leaves in his wake. The two have clashed several times, but every time their battle has ended in a draw as one or the other was forced to flee. In the final years of the 41st Millennium, this hunt seems to have drawn to a close, as Kyras and his allies of the Sixteenth Legion are facing Gabriel and his allies in the Aurelia sub-sector, in a war that has engulfed half a dozen worlds.

Over the years, Gabriel has accumulated many varied allies. His forces haunt the Aurelia sub-sector from the infamous Space Hulk Judgement of Carrion, and he has made pacts with the Greater Daemon of Nurgle Ulkair. Warriors of the Black Legion – these surviving clones of Horus created by Fabius Bile during the Clone Wars ten thousand years ago – also fight by his side, as do all kind of renegades, be they human or Space Marines. This warband, like its dread master, calls itself the Blood Ravens, and is dedicated to the Blood God Khorne, though it is allied with disciples of the other Dark Gods.

To those who know of Khorne's infinite hatred for sorcerers, it might appear strange and contradictory that a son of Magnus might fall to the service of that particular Dark God. However, while Khorne abhors the use of sorcery, seeing it as a coward's tool, Gabriel only uses it to enhance his own martial abilities. Yet still, that distinction is thin, and the sons of Magnus fear that the Blood Raven is actually a sign of something far more terrible. They fear that Angelos is actually fulfilling an ancient prophecy, written by Revuel Arvida, a Sergeant of the Fourth Fellowship during the Heresy. That prophecy claims that the doom of the sons of Magnus shall be heralded by the coming of a blood-soaked raven, who shall crack open the doom sealed in ancient days and let loose a tide of blood to drown the galaxy.

Recruitment and Geneseed

The Thousand Sons recruit mostly from the Prosperine Dominion, but also take in aspirants from across the galaxy. When a group of Legionaries come across a youth of great potential, they will claim him for the Legion, and have him sent to Terathalion for testing. There are also Apothecaries of the Fifteenth Legion who spend their days aboard the Black Ships used by the Imperium to harvest its tithe of psykers. There they search for souls worthy of Ascension, side by side with Inquisitors seeking useful servants and the stringent recruiters of the Grey Knights.

Once on Terathalion, the aspirant will be tested, both physically, psychically and spiritually. Once he is determined worthy, he is trained in the ways of the Cults, until his favored one is identified and his training becomes more focused. He is also taught the more traditional ways of war, for the Thousand Sons have long since learned not to rely on psychic might alone. When the training is complete, the aspirant begins the surgeries that will make him a Legionary – and with them, his true trial.

Even with all the effort the Thousand Sons put into selecting suitable aspirants, the ratio of those who make it through the actual procedures is appallingly low. The reason for this lies in the instability of the Fifteenth Legion's gene-seed, twinned with their increasing psychic potential, that caused the curse of the flesh-change to ravage the Legion at the dawn of the Great Crusade. When Magnus led the Legion, his power shielded the them from mutation, but with the loss of his spirit to the Warp, the Thousand Sons were forced to use other means to protect themselves from the flesh-change. Their salvation came from Ahriman, but with it came also another curse.

During the long months of their transformation, the would-be Thousand Son must endure the constant flux of psychic power that Magnus' bloodline carries. Once all nineteen organs have been implanted, the aspirant is clad in power armor and subjected to the Rubric, in a re-enactment of the great ritual that Ahriman led ten thousand years ago, albeit on the scale of a single Legionary. This ritual, if successful, protects the subject from the flesh-change, but also from all Warp-induced mutations. It also increases the psychic power of the new Space Marine, by allowing him to tap deeper into the Sea of Souls without risks.

The Rubric

While the effects of the Rubric are widely known among the Inquisition, absolutely nothing of its workings has ever been revealed to the Holy Ordos, despite uncountable attempts over the course of the millenia. This secrecy has, naturally, bred suspicion that the Thousand Sons were forced to resort to fell powers to protect themselves, and almost caused a civil war on at least two occasions. Each time, the Grey Knights have intervened, vouching for the sanctity of the Rubric, claiming knowledge dating back from the days of its inception. According to the sons of Titan, their forebears were present when Ahriman cast the Rubric for the first time, and while the powers it manipulated were considerable, they were untouched by the Ruinous Powers. Faced with such claims, the doubtful Inquisitors had no choice but to retreat their accusations.

Still, other agents of the Ordos seek to pierce the Rubric's secrets. Their masters hope to perfect the ritual, or even simply generalize it so that it might be applied to baseline humans. Several attempts have been made to recreate it from scratch, using captive mutants as experimental subjects. More often than not, the Inquisitor or savant attempting this is driven mad by failure after failure, and either ends up dead or turn to other, darker powers to succeed – ironically committing the very sin the Thousand Sons were falsely accused of.

In these Radicals' vision, the entire Human race could be purged from mutation forever if the work of Ahriman could be adapted to an even greater scale. Certainly, the thought of Mankind being freed forever of the aberration of the mutant is a pleasant one, but one must also consider the horrifying death ratio of the existing spell. But in the mind of these men and women, the trillions of dead that would come with a species-wide Rubric would be acceptable losses for the protection of Mankind's genetic purity.

However, very few aspirants survive the Rubric, and the gene-seed of their bodies is then irredeemably lost. Without access to their Primarch's comatose body from which to carefully extract genetic material, the Thousand Sons would long have been extinct, unable to replace the gene-seed lost whenever the Rubric fails. With it, it is all they can do to keep their numbers above a single thousand warriors, echoing their Legion's name with bitter irony.

This has another effect on the Thousand Sons' mentality. Death in battle is a certainty for all Astartes, but those of other Legions can take comfort in the knowledge that their genetic legacy will endure, and in time will be carried by another Space Marine, just as they themselves carry the gene-lines of past heroes. The sons of Magnus have no such comfort, for few gene-lines of the Fifteenth Legion survive more than a handful of generations. They are, all of them, sons of Magnus, without the distant genealogy of the other Legions, and their legacy will be nothing more than the deeds they themselves perform during their lives.

At the same time, their pride is fuelled by how genetically close they are to their Primarch, unlike those whose blood has run through dozens of generations over the millenia. The other Loyalist Legions look upon that pride with compassion, for they know the true hurt that lurks beneath the façade of cold detachment the sons of Magnus expose to the world.

Warcry

The Thousand Sons do not simply shout their war cries at the foe. Instead, they turn their battle-cries into weapons of their own by sending their oaths ahead of them in powerful telepathic bursts, capable of overwhelming weak minds and causing brains to explode. Yet the sons of Magnus still take some simple, primal gratification in screaming their cold fury at the top of their lungs for their mortal allies to hear. Almost every warrior of the Fifteenth Legion has his own personal battle-cry, but there are a few that are used throughout the scattered ranks of the Thousand Sons, like 'For the Crimson King !', 'For the Emperor and the Cyclops !' or 'Ash to ash, dust to dust !'. When facing the hated Sixth Legion, however, all Thousand Sons go to battle with only one cry on their lips and emanating from their minds : 'Remember Prospero !'

Khrove screamed for several minutes as the Rubric roamed through his physical body as well as his ethereal form, binding the two together on levels unknown to even the greatest Librarians of the Fifteenth Legion alive in this age. The Apothecary overseeing the ritual, Asim, looked on expectantly. Khrove had been a rare find, an indentured scholar on Prekae Magna whose psychic potential had gone unnoticed by the Black Ships, yet had failed to draw any Neverborn to his soul. Asim was convinced that he would survive the Rubric …

But the scream fell silent, and Asim fell his heart grow heavy as one more of the Thousand Sons was lost. Out of habit more than any real hope, he reached toward the former aspirant's still body, trying to touch the soul within the armored form. He felt nothing but a shadow, a ghost trapped inside the armor. Despite the number of times the Apothecary had seen the exact same thing happen, he felt the twinge of guilt and sorrow in his soul.

"Follow me", he pulsed, and the dead warrior began to move, his hands still clasping the bolter that had been given to him at the ritual's beginning, in the hope that the weapon would hope him to keep his focus throughout the Rubric.

Asim and Khrove marched through the silent underground corridors of the Terathalion fortress. Soon, they emerged into an immense chamber, at the center of which rose a pyramid of white marble. Atop that pyramid, laid down on a bier, was Magnus' body, waiting for the day his spirit returned from the Warp.

And all around that pyramid were ranks upon ranks of the Rubric's victims, standing eternal guard over their father-in-death. With another mental pulse, Asim sent Khrove to take his place among them, next to the previous aspirant who had failed to endure Ahriman's spell. Were there thousands of them, tens of thousands, or more ? Asim didn't know. Every accursed time he walked into that chamber, he kept his focus on the Primarch's body, because he knew that if he looked around, his eidetic memory would remember the chamber perfectly, and his mind would count how many there were.

And that was something he didn't want to know. He turned away and left, the heavy doors slamming behind him.

At the foot of the pyramid, among the very first rank of statue-like warriors, a glimpse of light danced in the eyes of one of the ashen dead. His name was inscribed on his battle-plate, still perfectly functioning after ten thousand years of silent watch :

Helio Isidorus.

---

AN : hello, dear readers. Yes, I know I said that the next chapter would be of Warband of the Forsaken Sons. What can I say, I got hit by a sudden wave of inspiration. Through it, and really massive amounts of research, I was able to write more than ten thousand words in two days, entering a sort of trance where my fingers just kept hitting my computer's keyboard. But anyway, back to the chapter.

The Thousand Sons have long been, in my eyes, one of the most fascinating Traitor Legions of the canon WH40K universe. On one hand, they never really wanted to turn against the Emperor : their hand was forced by Tzeentch, by Horus, and by the Wolves. But on the other hand, they just can't seem to accept their own part of responsibility in what happened to them. It was Magnus who looked too deep into the Warp, even when the Emperor warned him not to. It was the Thousand Sons who arrogantly dismissed the warnings of the White Scars' Storm-seers, believing them to be ignorant because they refused to drink too deep of the Warp's power. And it was Magnus who, when he tried to warn the Emperor of Horus' treachery, chose to accept the help of a daemon god instead of, you know, taking a ship. Sure, it would have taken longer, but I am pretty sure he would have gotten to Terra in time to prevent the Isstvan Massacre, and inform the Emperor of Lorgar's part in the Heresy, at least. The entire galaxy would be a much different place if Magnus had not let his pride get to his head.

You will remark that there is little changed here in the backstory of Magnus on Tizca. The truth is, we know very little of Magnus' infancy, which is ironic considering that he remembers everything from the moment he was in his pod in the Sol system. The only change I made is the battle with the Psychneuien-Prime, which I entirely made up so that Magnus would still lose his eye and to teach him a lesson about over-reliance on psychic powers. The true change was how Magnus didn't fall to Tzeentch's deception and found another way to protect his sons from the flesh-change. Of course, the Rubric still happened, and as you probably already suspect, the ranks of ashen dead guarding Magnus' body will have a place in the Times of Ending.

About the Times of Ending idea : I have continued to write some notes about them. I also have decided that when I get to it, it's going to be in a format similar to those used by the End Times official Warhammer books, i.e. it will be a series of chapters/arcs, each bearing the name of one famous character and focusing of his actions and their impact on the universe.

As always, please follow, favorite, and leave a review. This story has more followers by the week, and each review you leave behind motivates me to write more ! If you have any questions or see an incoherence, please send them to me too. Doing so can actually alter future chapters : it was because of two such messages that I thought of the story with the Sisters of Silence, instead of forgetting them completely. So if you have a bit of Imperial history that you want to see included here, contact me !

Alright, that's all for today. Next up should be the Forsaken Sons, or perhaps a short story. Don't forget to check Nemris' art page on Deviantart for his artwork on this fic !

Zahariel out.

Edit : modified the circumstances of Amon's death after Teefplucka pointed out some conflict with the Iron Hands chapter. Thanks for pointing that out !

Edit 2 : if you want to see more of the Thousand Sons in the Roboutian Heresy universe, check out Blood of Ignorance, by Jaenera Targaryen. Not very long for now, but what there is is very well written.