i'll drag my army fluff from the depths of my depraved mind today and edit this post later
edit; here it is...enjoy
History of Lord Xinn
By the time the traitorous warmaster rebelled against the rightful rule of his father the Emperor, brother captain Calistinos was a veteran of many campaigns. Indeed he could clearly remember the Emperor's address on the eve of the Great Crusade before the silver fleets left the Terran system to liberate the worlds of man, when the Lord of Earth laid out his grand designs for the galaxy. That day a dream took hold of his heart, and a vision of mankinds destiny free from the malign influence of aliens, dark age technological slavery and pseudo-religious constraints, that would become the driving force of his life took root in his mind. The Emperor's age of enlightened thought and forward progress was a goal worthy of a mans life.
During the great crusade Calistinos fought with honour, loved the Emperor and served his Primarch with distinction. He brought many new worlds into the Emperor’s realm and prided himself on using diplomacy as often as force of arms to do so. He became a shining example of the Emperor’s vision.
When the traitorous Warmaster rebelled against his father Calistinos was as shocked as anyone at the betrayal. Heeding the orders of Rogal Dorn, Calistinos rushed his forces back to Terra, and arrived just in time. He stood on the walls of the Emperor's palace as the traitorous servants of Horus assaulted earth and yelled his defiance at the heretics as he slew them. When the Emperor went to confront Horus aboard his own ship calistinos begged to be allowed to join him, but the Emperor forbade it, saying that if he was to succeed in his task good men would need to hold the walls of the palace in his stead.
When news of the Emperor's dire condition after his duel with the arch heretic reached his ears, Calistinos went berserk. Defying the orders of his Primarch he gave chase to the traitors, harrying them across the galaxy and following them into the eye of terror itself to punish them for their sins. For many long years he and his company fought in the very stronghold of their enemy, venting their rage against the betrayal of their brothers. But when they returned to real space Calistinos was shocked to find that a thousand years had passed. The Emperor had been installed on the Golden Throne, the Primarchs had all died or disappeared and the Imperium was under the rule of lesser men, the High Lords of Terra. Somehow, through the many years of his absence, the Emperor's grand vision had been lost.
Calistinos immediately contacted the rest of his legion, who promptly fired upon his fleet after labelling them excommunicate traitorus for disobeying Dorn’s orders. Calistinos was stunned to the very core of his being. Everything he had fought for was gone. The Emperor’s realm of enlightenment had been replaced with the very thing he had fought to oppose; the Imperium had become a xenophobic and paranoid religious theocracy. The High Lords were keeping the Emperor imprisoned on the Golden Throne and using his authority to do as they pleased. This was a betrayal equally as great as that of Horus!
For decades the fleet wandered the galaxy as renegades, sometimes attempting to help beleaguered imperial forces in times of need, but never welcomed, and always disgusted at what the Emperor’s realm had become. Slowly it became clear what must be done…the Emperor's dream was dead and the shining vision he had fought so hard to create was now beyond reach. The only thing that remained was to allow the Emperor to die and to tear down the obscenity that the High Lords had created. The Imperium must burn!
With a heavy heart, Calistinos embraced the one power in all the galaxy that could accomplish this…the dark gods of the warp! He sought out Abbadon and pleadged his allegiance to the Black Legion, and in that moment brother captain Calistinos died, to be reborn as Lord Xinn.
Since that day Lord Xinn has set about destroying what he once helped to create, with hatred for the High Lords of Terra and despair for the actions they have forced him to take always festering in his heart. More than once he has attempted to sway loyal servants of the Imperium to his cause by showing them the truth of the past, using the gifts granted by the gods of the warp to imprint his own memories into the minds of others, pulling down the realm of man from within and without, his once heroic name now rooted in infamy.
(this may not be a true fluffy representation of the crusade or the heresy, but is an insight into the mind of lord xinn and is told from his point of view, so you can forgive me right?
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