This will be AU. Meaning, an alternative universe, I admit that I don't know all the lore of 40k but then again, the damn lore is vast, and even then that word doesn't do justice to it, so I will have to do some research on some things. So expect some things to not happen and others to be different.

I'm warning you now, English isn't my mother language and keeping in mind my nationality, very far from it actually. Even then, I don't think my English is horrible, but there may be slight mistakes here and there, and the worst part is I don't have a beta-reader, so yeah.

Also, chapters for this story will be at random, meaning when I get them done, I don't have the whole story planned out. You can consider this as an experiment of mine, the TS, more specifically pre-heresy, is actually one of my two favorite legions and the only chaos legion that I actually like. Cookies for those that can guess the second legion that I love.

So if I go let's say ghost for a while, don't panic because unless I say that I'm officially dropping it, I'm not discounting it. Though if I do go let's say 6 years without an update then you can consider that I have passed away, lol.

You all know I don't own Warhammer 40k and everything else except for maybe the OCs.

And now, I leave you all to the story.

1rst POV

I died, at least it is what I could remember, but then again, I doubt someone can survive a bullet to the head unless they have been blessed by lady luck herself. But that isn't the point.

The thing now is that I'm randomly floating in darkness, there's no sound, no light or air wherever I find myself. Being raised by a Christian mother, I thought hell and heaven are what one will find after death.

I don't know how long it has been since I appeared here, it could be hours, days, weeks, or even months for all that I knew. I long realized that the perception of time here isn't a thing.

Being stuck in here alone with nothing to do, I soon realize that the only thing to do is think, and let me tell you something, I had thought a lot, more so about my past life.

As time passed, I could feel my sanity starting to slip, slowly but surely I could feel it as it started to fade.

I'm sorry, I haven't presented myself, have I?

My name is Leonardo, an Italian young man who lived in the United States, finished studying college, and not long started working as an interpreter for an airline company. No family, unfortunately, both of my parents have passed away in a car accident.

I was walking back home after a long day at work, but from what I could remember or understand from the blurs that compromise my memories just prior to my death, I have been assaulted, robbed, and then shot in the head. I know, a sad death isn't it?

But that's how I ended up here. Have I told you about my body? Or better yet, my lack of a body. Yes I know, it sounds crazy, and I can't promise that I'm not going crazy, but right now I'm just a…floating smoke? That's the best way I can describe my present physical form.

Suddenly a floating ball of light appeared, bringing some light into this dark place, looking at it, it has what to me appears to be two black circles in the middle. I could only assume that those were its eyes.

" This is unexpected, you are the third soul that somehow got deviated from the stream of souls to their judgment. The last one was centuries before you."

Stream of souls? Judgment? What is this light bulb talking about? I wish I could speak to it, but it is kind of impossible due to the lack of a body.

" I'm neither a bulb of light nor it, you fool. Just think what you want to say and I will hear it, it is called telepathy."

Well, this is embarrassing, but then again, I have never met someone who could read my mind before.

' Who are you? Where am I? and most importantly, what's going to happen to me now?' I thought, trying to express my thoughts with as much clarity as possible.

I don't know if I really did see it or if I have finally gone crazy, but the…ball of light bobs up and down as if nodding in confirmation.

" To answer your questions in order, I'm a supreme being, that's all you need to know, my name is not meant to be spoken by mortals or lesser beings, the simple knowledge of it would drive you insane." I nodded in acceptance, or at least I tried until I realized my mistake.

' I understand.'

" As for where you are, well, you are in the void, a pocket dimension that has long been poisoned by the negative energies from the different worlds of this dimension." Well, that's something new, although I have nothing to say about that.

The being surely heard my thoughts because he quickly continued.

" And as for what will happen to you, I will be honest, because you have somehow drifted away from the mainstream of souls to face your judgment, you can't return to it, even I can't send you back there, I would be breaking some ancient laws and I'm not interested in doing so.

But what I can do is give you a choice, if you keep staying here, it won't take long for you to lose your sanity, and later on, your soul will self-destruct.

So here's my offer, either I vaporize your soul and forcefully reincarnate it into a new life, simply make you fade from existence, or I send you to another dimension of my choice where you will keep your memories and do whatever you want, in one word, transmigration.

Carefully think over this because the moment you make a choice, there is no return." Well, shit.

That's honestly all I could think after hearing that, who would have thought that I would end up like this. As I think over my options, I realize my decision is already made. I'm not willing to die right now and reincarnation would be my next life, I quite like being who I'm at the moment. Thank you very much.

So I'm left with one option.

' I pick transmigration.'

" Very well."

Out of nowhere, a giant roulette appears to our right, I focus on it, and I notice many names, some known and others unknown, but they all have one thing in common. If I had a body, I'm sure a chill would be creeping through my spine at the mere realization.

" I went through your memories, and have decided that you will go to this universe that you know as Warhammer 40k, with that roulette, we will decide who you will become in this new life of yours."

' Are you ins- I can't go there, there is nothing but-'

" I warned you to carefully think over your options, you made your decision, and now you will see it through. I will spin it for you, and if fortune favors you, you may get something good." Right after his words, the roulette starts spinning.

It felt like hours before the roulette started to show any signs of slowing down, I started praying to every single god that I knew of, I pray that whoever the roulette is gonna stop on is going to be someone powerful where I have a chance at surviving the incoming hell that's the Warhammer 40k universe, preferably one of the primarchs.

As the roulette slowly stops, I see the arrow seemly about to stop on the name of Roboute Guilliman, at seeing that, I got my hopes up, Guilliman is known for being one of the most powerful primarchs, maybe not in terms of brute strength, but his mind on the other hand…. The primarchs were created to become leaders and rulers, but even then Guilliman broke the expectations and conquered his planet and those near it, creating a small empire with his homeworld as its seat of power.

But my hopes were cruelly and sadistically smashed down when the arrow skipped the name of the prior mentioned primarch, and stopped over the name of Magnus the red, upon seeing that, i started to despair, i didn't want to be one of the traitors primarchs, much less become a slave to the god of change.

I stared at the name in shock for seconds before I turned toward the ball of light, and gave him a stare.

" Don't look at me like that, it could have been worse. Besides, I'm not completely heartless, the time period that I will send you will be the day before the emperor reaches Magnus's Home planet, Prospero.

Not only that, but I will grant you the option to change some of Magnus' physical appearance if you desire."

At this I felt hope once again, if I'm sent at the time the supreme being just admitted, then I could change history so that I wouldn't become a minion of the chaos god of change. And probably save some of the loyal primarchs that originally died.

' Thank you for your generosity, and yes I do wish to change Magnus' appearance.' Not long after I finished the thought, a scroll appeared in front of me.

In it is the perfect image of Magnus only wearing a red piece of cloth to cover his sex organ, everything else is exposed. It shows Magnus still having both of his eyes, with Iris being a dark pink, his red hair, and dark bronze skin. But I noticed something that confused me.

'Why in the section of height, it says 10 ft to 18 ft tall?' I mentally asked the supreme being.

" It is because due to Magnus' sheer psychic power's biology, he can intentionally change his height. 10 ft in general and can grow bigger than that, with 18 ft being the maximum he can grow at the present."

Well, at least I don't have to worry about my height. I focused back on the scroll, and after looking for a little bit, I tapped Magnus's hair and above it showed all colors I could pick from, I was tempted to change the hair to a dark black, but I decided not to and leave it as it is, I did change the hairstyle though, instead of me having a lion mane of hair, it would be in a long textured waves style, it still looks like a lion mane, but now at least it doesn't defy the laws of gravity. I also changed his bronze skin to a light tan one.

Having done my changes, I signal to the light ball that I was ready. Suddenly, a flash of light forced me to close my eyes in slight pain, and afterward, I lost consciousness.

-Prospero.

I suddenly gain consciousness, and I wake up on a bed, a comfortable and large bed. I turn and the moment I lay on my back to look at the golden ceiling, I gasp as I suddenly have the most painful headache I have ever suffered in my life.

I felt like my head was being split in two, I grip my hands into fists and gripped the bedsheets, I was gasping and growling, desperately trying to bear the pain and not scream, alerting and bringing the unwanted attention of those nearby. Suddenly I find myself going through memories, memories not my own.

In the memories, I saw how the primarch known as Magnus was founded and adopted by the man known as Amon, the greatest Sorcerer and psyker on Prospero at the time. He saw his childhood, how from an early age the original Magnus had an obsession with knowledge and the immaterium.

I saw his life, when he came to power as the ruler of Tizca, his campaign against the psychic predator-beasts that roamed the countryside and the many empty cities.

Technology advances and how he United the different and influential cults and families. How the city of light began to flourish under his care, and cities that used to be abandoned are now full of life.

Tizca, the capital, was transformed into a city of breathtaking beauty. Beautifully designed buildings in the form of pyramids and towers composed of glass and marble, wide boulevards, paradise-like parks, and a constant pleasing psychic background, resulted in immediate bliss for all visitors.

This period of peace, prosperity, and psychic well-being reflected on the world's population of powerful psykers, and Prospero became a place of physically and spiritually beautiful humans.

But the most noteworthy memories are the many meetings between Magnus and the Emperor in the past in the immaterium. I gasp in pain at first when I saw the emperor in the memories, all those books, paintings, and arts didn't do him justice,

Something about him, something about his presence pierced through any protection of human audacity or the nature of humanity and mortality. His golden armor and light, his golden eyes staring through me. I felt like an ant compared to him, even though now I'm supposed to be the only psyker capable of matching him in power in the future.

I could only imagine that was my remaining human and mortal side reaction, a part of me that is already quickly disappearing from what I could already feel as my mind is adjusting to the body that I now possess. I could also feel my character changing as I'm assimilating the memories of the original Magnus.

Suddenly, my mind quickly goes through the knowledge over the immaterium that Magnus has learned in his life, and I admit, I am shocked that I now possess the ability to accomplish the same feats.

As minutes go by, the headache slowly diminishes till all I have left is a slight pain in my temples. I groaned as I sat up on the bed, pushing the bedsheets away from my body.

As I sat there, trying to process the fact that at this moment I'm Magnus the red, the crimson king, someone who along with his brothers can be considered demigods, a fictional character of one of the grimmest and darkest fictional worlds, I tried to look for the fear and panic that any person who has knowledge of this universe would have if they find themselves in my place.

But I couldn't find anything but a dull echo instead.

I wondered if that was a trait of what I had become? I felt my fear and despair only as a dull echo which is already fading away.

Normally I would have expected panic and anxiety, but the only thing that I could do was merely sit there in silent contemplation.

I guessed that I could know no fear so to speak because I could still feel my other emotions perfectly fine, I could still feel emotions such as my actual confusion, anger at my situation, and wariness toward the future.

I looked down at my enormous but proportionate hands and let out a deep breath which immediately made me feel the beat of a second heart.

For some strange reason, the mere knowledge that I have not one, but two hearts briefly amused me. It could have been due to the fact that it reminded me of a certain greedy shinobi in an anime I used to watch in my youth….I believe the name of said anime was Naruto? Perhaps, or perhaps not.

Even the sheer sensory overload from having all my senses amplified and altered was strangely muted as if they had always been that way and it was only now that I have taken notice of them. It was like a veil that has been there without my knowledge for the entirety of my life has been finally lifted, revealing to me what I have missed and filling me with a feeling of fullness, as I'm finally whole again.

I focused my eyes and thoughts on the room that I now know was the private chambers of Magnus.

My eyes took in the room that I find myself in, it is mostly in gold with red veils and clothes hanging from the ceilings and walls, there were four bookshelves against one of the golden walls, it was full of books, scrolls and what appears to be diaries and notes. The room has an Egyptian theme.

" But then again, the legion and Prospero itself always had an Egyptian theme," I murmured, initially surprised at how deep my voice is compared to before. I then took notice that there was a mirror on the far right of the wall. I decided to get up from the bed and I did so with a slight groan, I walked closer to it and I saw my reflection.

I'm currently standing at the height of 10ft, which I decided will be my standard height for the most part of the time unless I have to take a bigger form in battle. I'm wearing a long red robe, it has what looks to be golden Egyptian hieroglyphs and prosperian writings along the edges and shoulders.

But it was soaked in sweat, I can only guess that it was from early. I decided to go and take a bath. The memories led me to the door on the far left of the room, flanked by two small pedestals with two statues of two cats.

The moment I walk in, I was greeted by the sight of the enormous bathroom, a big pool in the middle with some stair steps leading to it, there are some leaves in it, they are a special type of leaves from unique trees that grow at the edge of the city, they give off a good smell, and thus are used for baths along with other activities.

There are veils and clothes hanging from the ceiling and walls, some plants, and the torches in the walls are illuminating it.

I turn back to the large pool of water, I walk down the steps until I'm at the edge and I crouch down to a knee before dipping my large hand in the cold waters.

I focused for a moment only and my hand suddenly started to glow a bright red, I could feel the heat of it as the water started to boil and steam a little.

" Fascinating, and this is only a cheap trick, psykers are scary, I can only shudder at what the emperor is capable of on the battlefield.

But if it is as terrifying as what Magnus was capable of from what I have seen from his memories, then I wonder how he got so injured to the point that he got stuck on that throne." I murmured, amazed at the feeling of power flowing through my body and mind.

This is one thing I noticed, since I have awoken, my mind and body were full of this power, it's like I was psychic energy and power itself.

Another thing is that I have been feeling the presence of people around me, I could only guess that those were the souls of the people that are walking outside my chambers and those deep inside what I now recognize, from the memories of Magnus, the Pyramid of Photep, the sanctum of Magnus himself.

" No….it is now my sanctum, I have to accept the reality that now I'm Magnus, my past identity no longer exists.

I have to accept this fact if I want to survive the hell that I will have no choice but to face in the near future." I spoke to myself as I closed my hand that was in the water, into a fist.

3rd POV

As Leonardo, or better say, Magnus accepts his new identity and abandons his past identity, he gets rid of his robe before entering the pool, submerging himself. The former normal man now turned into a primarch bath himself in the warm water.

When finished, Magnus dried himself by using a quick trick with the warp, and later walked back to his chambers in the nude, he quickly dressed in robes that were inside a giant closet.

He dressed into a long white robe with golden linings, with a red cloth wrapped around his shoulder and half of his clothed chest. Along with this, he put on some open sandals. He arranged his hair backward but two long bangs of hair fell on each of his shoulders and reached his chest.

After finishing, Magnus turned toward a desk that was against the wall next to the previously mentioned bookshelves and near a large balcony where he knew he would be rewarded with a beautiful view of the city of light.

He walked toward the large desk and his eyes ignored the scrolls and open documents, his gaze went straight to the lone book.

The heavy book is bound in faded leather and stitched in gold. An iron pendant worked in the form of the sun of Tizca, the symbol that the future XV legion will bear, lay along the valley at the meeting points of its pages.

Magnus knew what this was, it was the most prized creation of the original Magnus, and what now is his grimoire.

This is where the original has written all the spells, arts, rituals, formulae, incantations, rites, and sorceries that he has learned or created. There are also notes such as warnings and the required ingredients for some of the rituals, sorcery, and spells. Certainly a most unparalleled treasure for any psykers.

The grimoire was locked thanks to a lock that seals the book close, it would only open once he release a small burst of psychic energy, and thanks to the powerful runes and Hieroglyphs that he has carved, it would only open if the burst of psychic energy belongs to him, no other psyker will be able to open it either by force or by attempting to meddle with the runes.

The grimoire is indestructible, the pages were fire and waterproof. The number of pages will continuously expand so that its creator can record all new knowledge he might learn.

The grimoire also has a rune that makes the book keep its current shape so that it will be easier to carry instead of it growing bigger, preventing it from transforming itself into a large tome.

It also has two lines of defense if someone who is not Magnus were to open it, even if the possibility itself would be near impossible.

The first would be that whoever opens it would be the victim of many different and dark curses, specifically designed to cause pain, death, and destruction to the body, mind, and soul of the victim in a multitude of different ways.

The second one makes the grimoire unbound by physical laws, the words written on its pages will crawl and shift as though alive, changing constantly in shape and size. Making the task of learning its secrets naught but impossible.

Magnus slowly reaches for it before grasping it with his left hand and tying the book to his belt, tied by a golden chain.

Ready, the once human now primarch walks out of his chambers and into the grand hallway of his sanctum, he is met by two men guarding his chambers.

" My king!" The moment the two guards saw their ruler stepping out of his private chambers, they kneeled.

When Magnus heard their words, he turned toward them, but he froze, why you may ask? Because the moment he laid eyes on them, he could not only see their physical body, but could also see their souls in the immaterium, and their minds an open book for him, this is why he froze, because he was assaulted by their thoughts in a moment of unexpectantly.

' Lord Magnus is up earlier than usual today.' ' I should warn the servants to prepare breakfast for his highness, he's most likely going to be hungry after sleeping throughout the whole day yesterday.' These were the thoughts of the two guards that Magnus read before he stopped reading more of their thoughts.

Magnus briefly remembers that those that the original would gaze at would feel their thoughts and substance to be no more opaque than glass, and their innermost secrets laid open beneath the Crimson King's stare.

' I should have expected this from the memories, it is a good thing that it occurred now though, I should take note of not using my telepathy when in the presence of my brothers, I'm sure that they will not be happy about it.' Magnus briefly thought to himself, knowing that he's gonna have to work on not having telepathy always active, a habit picked from the original, after all, it is common for psykers in Prospero to communicate through the mind.

' Wait! I slept through all day yesterday?! Why? Could it be because of the body, or better yet, my soul was getting adjusted to the body?

But if that's the case, then today is the day where….shit.' Magnus thinks as he realizes that today is the day when he will meet one of the most powerful beings in the universe, and now his creator.

Magnus focuses back on the two guards who now are slightly nervous by their king's silence. Magnus noted that they wear red robes underneath armor of a strong and durable metal of Prospero, with golden shoulder guards with the symbol of scarabs engraved.

They have spears as weapons and what appears to be a gun similar to the autopistol, but a different model. He also took notice of their tan skin, tattoos that he could only associate with Egyptian symbols.

Thinking that it was time to speak, Magnus calmly spoke in his deep voice.

" Both of you can raise yourself to your feet. I appreciate your duty, but there is no need for you to kneel." Magnus' words shocked the two guards before they quickly raised to their feet.

" My king, do you wish for us to tell the servants to prepare breakfast for you?" The guard at the left asked the giant king, knowing that his king was probably already expecting his question.

Magnus shakes his head in negativity.

" There is no need as I'm not hungry. Although there is one thing that you could do for me. " Magnus politely denied before requesting the assistance of the guards, who quickly nodded their heads, ready and willing to follow and accomplish any task their king wished.

" Send a message to all the magisters templi, tell them to meet me at four on the dot at my throne room, tell them to not be late because I won't tolerate any lateness," Magnus ordered, and the two guards quickly nodded before they departed, on their way to complete their ruler's order.

Magnus sighed after seeing the two guards turn around the corner of the hallway. He wasn't sure what to do now, either prepare the city for the arrival of the emperor or to begin the normal routine that the original was known to do.

In the end, Magnus decided to follow the routine of the day, which consists of checking the requests of nobles and families, merchants, and new buildings construction requests.

As he goes through the documents in his office, he denies some requests while those that got approved would get his signature and would be put in a separate pile of documents.

It's almost scary how well he's doing his tasks, even though he has received the memories of the original, the way he's acting and feeling is as if he has been doing this all his life.

As hours passed, he finally completed all the documents and paperwork that needed to be done for today. Magnus leans back in his seat, and closes his eyes, his office was in peaceful silence, well, that was before his door was brusquely opened.

Magnus couldn't help but open his eyes milliseconds before the door was opened, irritation could be seen in his eyes, but that irritation went away when he noticed who the intruder was.

A young boy of seven years, average in height for his age, has the tan skin that all people of Prospero are known for and short dark hair, but the most noticeable feature would be his sky blue eyes. Dressed in a red chiton with brown sandals.

The boy ran up and around his large desk, and before Magnus could say anything, the boy enthusiastically greeted him.

" Uncle! I finally learned the trick you showed me!" The boy was obviously excited to share the news with his uncle, said uncle was still seated in his chair, with a surprised face.

' Uncle!? How?' Magnus thought in pure confusion, but before he could say anything, a womanly voice spoke from the entrance of his office.

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Well, this is it for the first chapter. Let me know your opinions in the review section, also, if there are people who are very well knowledgeable in the lore of the thousand sons, Prospero, and the legion campaign record, please feel free to write to me in private messages, I would appreciate it.

I accept constructive criticism, not pure hate and foolishness, thank you.

A cookie to those who can figure out the identity of the person I referred to with the two hearts.