Author's Note: So... I'm surprised nobody used this idea as far as I know. If I'm wrong, please let me know, it'd be a pleasure to read where it'd go, though I have my own idea on what to do with this fifth God. I've seen of Machine (Dark) Gods and Ahriman attempting to be one, and obviously the Emperor dying and a new Eye opening, but not this, at least not taken seriously. Let me know if I'm doing it well enough.

At the end of the 41st Millennium, there was only stalemate. Though Abaddon's 13th Crusade threatened to undo all that Humanity had fought for for 10 millennia, though the races of the Galaxy were besieged by countless enemies on all sides and the laugh and the thirst of the Gods were quelled more and more, still it wasn't over. Still there was hope for humanity.

Still there was endless hate and unrealized potential for Abaddon.

He had tried just about anything. Xenos weapons from times forgotten by all but the oldest of things, rituals so foul even he couldn't stomach them sometimes, and so much more, all for the greater hate, for the greater revenge. Revenge against Horus by destroying Humanity as both the Emperor or Horus had imagined it or hoped for it. Hate for the Corpse Emperor who would deny him while being a fucking dying corpse on life support for over 10,000 literally bloody years. Hate even for the mocking of lesser daemons and of the Gods for his often half-failures.

But for all his hate and all that he had at his disposal, for all the literal Gods that were in his corner, there was one thing, one small thorn that grew and grew and grew in his side that kept stopping him. The grim determination of the uncorrupted. Even in this dark setting, that grimness, even that darkness, would protect them from his masters, even more than the faith in the Corpse Emperor. It let the Eldar continue their pitiful plan to build their own God, it let the Tau continue to fight for the Greater Good, even if not through hope, then through the same determination. It let even the mad gods of the materium, the C'tan, to continue their twisted existence even when they had been betrayed by their own kind and the servants they had given immortality to. It let the Necrons continue to wake and try to salvage their lost and unattainable rights of conquest. It let the Old Ones continue to live on the run in other Galaxies, continuing to breed new civilizations to keep the Great Spiral of their birth in chains should its inhabitants decide to cross its borders to spread the madness they had unwittingly unleashed, even if it seemed hopeless. But worst of all, it let Humanity survive for over 100 centuries. When. It. Should. Not. Have. Done. So.

And then Abaddon had an epiphany. Maybe his own twisted brain came to the conclusion, maybe Tzeentch or even a lower demon supplied this to him. Maybe any warped spawn would have arrived at the same conclusion with its two remaining neurons (if Tzeentch felt magnanimous with it) functioning closely enough to that if human ones.

What did Chaos do with those that stood in its way and couldn't win against them in a fair fight? It corrupted them. It turned their ideals against them, preferably towards Chaos. So what if the Corpse Emperor was unattainable? So what if this grimness sealed them from Chaos? So did the Omnissiah - and oh did Abaddon hate that Ghost of the Machine God - and Chaos had turned half the Mechanicus during the Great Rebellion, hadn't it?

With these thoughts in mind and already formulating heinous rituals and sacrifices in his mind, Abaddon set to work at once. He had waited enough as it was. He called his personal guard and best witches and made planetfall to the part of Cadia they were in (somewhat) control of. If he were anything but Chaos, he would have been warned by his retinue that such a trip on what appeared to be a whim was foolhardy at best and would get them all killed if Abaddon was not certain of the Gods' favor upon them and their endeavor. Of course, none did and his defiled Terminator walked with him in set grimness. The thought made Abaddon smile in a long, long time and it was not a pretty sight for those that witnessed it.

Between the time he had the idea and when he made planetfall, the plan, the ideal, the future, the creation, the ritual, everything, had already fallen into place in Abaddon's mind. He didn't need to write down his thoughts, to disseminate them through their minions to worse, to remind himself of anything, he was the chosen of the Dark Gods and most daemons feared him and answered his questions truthfully, for they knew if they tried to cross him, what their patrons could do to them in their worst nightmares didn't compare to what Abaddon could. He wasn't their chosen just for his military mind and hate, as great as it raged in him. He had more... refined tastes that impressed even self-proclaimed Gods.

They were uninterrupted as they started their foul work, only the light oranges of sporadic bombardments and the scary beauty of the Eye piercing the black shortly before dawn. As instructed, Abaddon searched the black thing through time and space, below them, and finally found it, thought it seemed... reluctant? Unwilling? Abaddon was surprised, surely such a being would be as eager to be birthed as Slaanesh was when he was barely seeing the power the Warp could give him. No matter, reluctance and the weakness of others had never stopped him in completing his task.

After agonizing minutes, both of the physical and the mental, for both him and his minions, finally, it was done. He heard it, loud and clear, as well as most of the beings in the Galaxy, the Tau included. A roar of anguish, of darkness, strangely devoid of madness, but with a grim prospect, a great legacy. Abaddon smiled for the second time in a few hours' time. A new God was born and the Imperium of the Corpse Emperor and Horus would fall to him.

Disclaimer: I do not own Warhammer 4000 or the characters within the franchise, nor do I profit in any way from this story.