AN : Behold ! For the first time in years, a new story !

About two weeks ago, I had re-read the entire Ahriman trilogy, just after finishing The Crimson King. As a result, I was hungry for more Thousand Sons stories, and after the several What If ? I have already done for Warhammer 40K (What if the Emperor became a Chaos God, What if the Great Crusade Succeeded, What if Horus won the Heresy, and, of course, the Roboutian Heresy), I thought this one would be fun to write.

And boy, was I right. I have gotten way, way more involved in it that I anticipated. At first, I thought I would do like with the others : a short story of about 5k words depicting the changes in the universe, then a character wakes up in the canon universe and we realize it was all a dream. Canon is preserved, nothing bad happens, etc. But this one ...

This one was different.

This tale began on Spacebattles, and at first I intended to compile it and publish it in my short stories once it was completed. But it has grown beyond my expectations, and now, at more than 30k words and no sign of stopping soon, I thought it made no sense to keep to that plan. So, instead, here it is. The first thirteen parts of The Fifteenth Ascendant, with more to come. I did not write AN for each of them, because why would I, when they are published on the same day ?

If you have questions, or suggestion for what comes next, tell me in your reviews or by PM. I am writing this fic a lot less seriously than my other stories, which makes it much, much easier to write as a result. (On that note, the next chapter of Warband of the Forsaken Sons is still in the works, about 70% finished, but the remaining 30% are the hardest part to write).

WARNING : this is already mentioned in the story's description, but I think it bears repeating : this story contains spoilers for the Horus Heresy novels. Nothing about the Thousand Sons is safe, and little from the rest.

Zahariel out.

Khayon exalted. Power coursed through him, through every single one of Ahriman's cabal, strong and ardent and pure. Here, on the Planet of the Sorcerers, years after the humiliating defeat at Terra that had seemingly doomed the entire Legion, they were performing something Magnus himself had forbidden, for he had thought it impossible. Something Khayon, too, had thought impossible. He had put contingencies in place in case it all went wrong as he had feared it would – the Tlaloc was in orbit, with his brother Ashur-Kai ready to open a conduit and send his warriors through at his signal. But it wouldn't be needed, and never before had the Sorcerer be so glad to have been wrong.

He could see Ahriman rising in the air, arcs of unfathomable power linking him to the rest of the circle. Before him, the Book of Magnus floated, its pages turned by invisible hands, symbols flickering on its priceless velum. Its lore, poured forth from the mind of the Crimson King undiluted and untainted through the hands of Mahavastu Kallimakus, had been the foundation of Ahriman's work, and the immense power within was instrumental to the Rubric. Khayon could feel it burn through his body, infusing his every cell and reshaping his genetic code, curing the flaw that had been eating at him for years. The constant press of the flesh-change was fading more and more with every passing second, and he knew that every son of Magnus who yet lived – whether they were here, on the Planet of the Sorcerers, elsewhere in the Eye of Terror, or even beyond its borders across the rest of the galaxy – would feel it too.

Then, at last, the ritual was completed. The Rubric was cast, and the fate of the Thousand Sons was changed forever. There was a flash of light, bright enough to burn the eyes of any mortal. In the distance, Khayon could faintly hear the screams of the mutants that had ineplicably appeared on the Planet of the Sorcerers, as they caught sight of the power unleashed. His sight returned, and despite the exaltation of the cabal's success – for already, his mind could hear the joyful cries of his brothers all across the planet – his blood ran cold as he beheld the towering figure that stood before Ahriman.

'Ahzek,' spoke Magnus the Red. 'You disobeyed me.'

The Crimson King was as he had been since his restoration : tall and radiant with power, a being of infinite potential and wisdom, clad in elaborate bronze armor whose patterns shifted endlessly, forming esoteric patterns that drew the eye and threatened never to release the observer.

'Father,' replied Ahriman, standing tall and proud before his Primarch. 'You were wrong. It could be done.'

There was a moment of silence, and Khayon feared that Magnus would strike Ahriman down for his insolence – and then turn on the rest of the cabal. Khayon was powerful, and Ahriman even more so. In fact, since the moment the Rubric had been cast, Khayon could feel that his perceptions had grown, and suspected that his full powers might be far stronger than before. Through his bond to Ashur-Kai, he could feel the wonder of his old mentor as his own curse vanished and his powers grew, and his surprise as the rest of their warriors aboard were suddenly filled with energies they had previously struggled to call upon. It appeared that the Rubric had done more than saving the Thousand Sons from the horrors of the flesh-change : it had also energized them, elevated them to new heights of psychic power.

But all members of the cabal were nearly completely exhausted from casting the Rubric. If they were to face the wrath of Magnus, they wouldn't even have enough power to flee – the only chance of survival any of them had against the Primarch without extensive preparations.

But then the moment passed, and Magnus laughed. It was a sound filled with joy and wonder, and the arid sands around the cabal of Sorcerers blossomed with colorful plant life in response to the Primarch's thoughts. The nine suns above seemed to shine brighter, their light falling through the ring of souls that surrounded the daemon world. The Crimson King seized Ahriman and lifted him up, hugging him in a display of emotion Khayon had never seen in his Primarch.

'Yes !' roared Magnus, casting his head back and looking at the twirling skies with his eye, which glowed with a fiery intensity. 'Yes, you were right, Ahriman. It seems that Fate has smiled upon our Legion at last ! I thought we were doomed, that the Arhictect of Fate had turned on us and would only ever enjoy tormenting us. But it seems there is some mercy left in him after all – or perhaps he simply has decided that your efforts are worthy of such a grand reward. It matters not. All that matters is that you have succeeded !'

Magnus put Ahriman down, and turned to adress the rest of the cabal.

'You have done well, my sons. You dared to hope when I had lost hope, just like you dared to save me when I had given up life. I shall not repay your efforts with ingratitude. My brothers have abandoned their sons, drawn to the glories of the Great Game of Chaos. But I shall not abandon you to your fate, never again ! Alone, you have saved our Legion from extinction and given us a future. Together, we shall forge that future ! Though my father is fallen and Horus is dead, we will carve a path for Mankind's ascension ! As you restored the Thousand Sons, so shall we restore the dream of Humanity !'

The Crimson King lifted a fist to the heavens, magnificent and terrible, and Khayon felt the stirs of glory within him, the old embers that had all but gone to ash in the aftermath of the Horus Heresy. The Daemon Primarch seemed to glow with an inner power greater than anything he had ever displayed before, greater even than when he had been whole. After the end of the Siege of Terra and the Legion's failure to reclaim the remaining soul-shard of the Crimson King, said to be held in chains beneath the Imperial Palace, Magnus had gone hollow and bitter. But now, it appeared that, just like the Fifteenth Legion, Magnus was being restored, his power elevated by the Rubric.

'Here, in the Great Eye, we will rebuild the Prosperine Dominion, and recreate all the wonders of Prospero – and surpass them a hundredfold ! While the Imperium falls ever deeper into the darkness of ignorance, we shall keep the torch of knowledge alight. And when the lies that hold the Imperium together inevitably fall apart, we shall be the one to welcome Mankind into the light, and usher in a new age of illumination !'

'My lord,' said Amon, emerging from the ranks of sorcerers held in rapture by their Primarch's words. The Equerry of the Crimson King was one of the few who was able to not be completely swept away by the Primarch's enthusiasm, though even he was far from unaffected. 'The other Legions will not see it that way. They will fight us, as will the adepts of the Dark Mechanicum, and the other humans who have joined us in our exile to this place …'

'They will not stop us,' declared Magnus, his voice filled with confidence. 'For we are still warriors as much as scholars. Those who are able to see our power and truth shall join us, and be rewarded with the blessings of knowledge. As for the others, if the light of illumination must be preceded with the fires of ruin, then it shall be so !'

So started the rise of the Fifteenth Ascendant. So was heralded the re-ignition of the Legion Wars.