In the Warp.
Be'lakor was the first mortal to attain the status of a Daemon Prince. The sacrifices and horrors he committed to earn this reward were so unspeakable that they are recorded in no chronicle, not even the most ancient. Somehow, Be'lakor had managed to attract the attention of all four Dark Gods and please them enough to be granted a fraction of power from each. This soon proved to be a mistake, for the Gods of Chaos rarely share anything amongst themselves without conflict.
Be'lakor is the first Daemon Prince, a Champion of Chaos, dubbed the 'Dark Master'. He was the first to be raised up by the Ruinous Powers and is feared for his absolute antiquity and malice.
But this time, it was different. A newcomer, an irritant presence like the Anathema, had spread his wings: Julius Braveheart, the Lord Commander of the world of Bastion. This human already possessed one of the clone Todd's weapons, and with the powerful Terran machines he was beginning to acquire, he would soon become his equal. Such an eventuality was intolerable.
This could not be allowed to happen.
In the turbulent depths of the Immaterium, where his power was most absolute, Be'lakor summoned his most faithful daemonic servants. A court of horrors gathered around him, twisted creatures born of nightmares and betrayals.
"He must not grow," growled Be'lakor's voice, an echo of damnation that made the very substance of the Warp tremble. "This... maggot who fancies himself an eagle."
A plan formed in his millennial mind, as tortuous as it was cruel. He would lay a trap for the upstart. Either Julius Braveheart would bend the knee, adding his nascent strength to the Dark Master's army, making him an asset of unrivalled power. Or he would be destroyed, and his soul, already so bright and potent, would be devoured to feed Be'lakor's eternal glory.
At this thought, the Shadowed Daemon Prince roared with ancient pleasure, a sound taken up in chorus by his court of daemons, thirsting for carnage. For in the darkness of the 41st millennium, there is only war. And Be'lakor had decided that Julius Braveheart would be its next centerpiece.