Prelude to Incursion
Occanderael, bringer of Order felt a call from afar. A call from the holy, to negotiate, to bargain. To bargain. Such a rare event, already paid for with a billion souls, that none would call for them frivolously. From the palace of the Star Father it walked through the warp, ordering it as it went. It swatted aside the Bloodthirsters and Keepers of Secrets that found themselves in it's path. One day the Emperor would snuff them all out, along with the fickle, traitorous Eldar and their pathetic attempts at holding onto life in a galaxy that had outgrown them.
Such a familiar place. Valinor, a hub for fleets and a planet that was quick to pledge loyalty to the reborn emperor even as turmoil swept the Imperium. And nearby - Of Course. Anger returned to it's mind as it remembered the False Saint which led the flock astray. So many souls lost to the Emperor because of his honeyed words even as he dwelt upon a world little different from a daemon world, a far cry from the worlds of the Emperor, forged by sacrifices to allow his flock to mingle with his Saints.
The mortal before him called himself Herrion. Lord-General, as if the title was supposed to mean something. It did not. The mortal spoke of killing the False Saint when the Orks distracted the so-called 'Imperial Trust'. Occanderael had plans for that, but it listened anyway. Of how they would summon an Angel of the third circle - Apollyon, one he knew and respected. His skill had culled many, many of the heathens and heretics that had dared defy the Emperor.
Then there was the faintest shudder against the wards of the room. An attempt at spying, foiled. Occanderael looked about regardless, knowing from the whispers in the warp that the False Saint had waylaid a potent seer in his many sermons. Then the mortal crowed about his plan, how they would kill the Saint and end his little heresy. To Occandereal, it seemed as if the Herrion had called him here merely to gloat. He was tempted to strike him down for disrespect, but stayed his hand.
Now he offered him a bargain for part of the favor. To stand in the warp and be ready to emerge when called forth. In case they failed. For killing the False Saint the mortal expected a cheap price, but he failed to realize how much insult he had inadvertently given Occanderael. He answered with a simple demand. Twenty-four billion souls returned the Emperor now, and one billion more when they intended to summon him. The mortal balked, and Occandereal allowed a twinge of irritation to flow out. The mortal capitulated.
Occandereal did not believe the mortal Herrion could succeed without his aid, flawed was his character. But in failure much would be learnt. Occanderael would simply be there to emerge and slay the False Saint when the mortal tried and failed to do the task of an Archangel.
As expected, the failures began ratcheting up almost as soon as they entered the system. Insufficient screening. Failure to consider enemy action. Incorrect attribution. Arrogance. Then they arrived upon the planet, and the true horror of the False Saint's heresy was open to view. An alliance with metalshaping xenos. Utterly disgusting. Merely by staying near the home of the wretched False Saint Occandereal was forced to exterminate and chase off the daemons which assailed it constantly. Still Occanderael watched as the mortal Herrion follow a plan that continued to collapse around him.
He heard Apollyon's dying scream in the warp as Herrion wasted him on a failed assault. A legend turned to dust by incompetence. If the mortal saw clearly he would now summon Occandereal to end whatever could brought an Ending to Apollyon's story. But he did not. Unwilling to admit failure, the general threw everything against Dis. More and more wasted because the incompetent general could not admit failure and cede the slaying of the False Saint to Occandereal.
The Archangyl wondered if the general might waste his forces so utterly that he might run out of the souls needed to transpose him onto the Materium. The one called Ausvan for whom Occandereal had saw as marked by Emperor for glory by Yalia the Saint herself, dead. The Emperor's Talons, thrown away. And then the God-Machines fell as Herrion again refused to admit defeat. Again and again. Until he was forced to. To enact the ritual Occanderael had designed for them to summon him.
Bereft of the forces to protect the rituals, them all wasted, the sites failed one after another, surviving only by Occandereal's power holding the ritual stable. But as the 1st Circle prepared to step through, Occandereal felt the final ritual catastrophically fail as well. It seemed the mortal had failed yet again. He did not believe that such incompetence existed, let alone rise to such heights. But such as it was. The souls of the crusade left for the Emperor's side, failed by their general.
Staying only to witness how the crusade ended, Occandereal realized now the full extent of the debasement the False Saint had led them to. Not just Xenos, but Eldarlike Soul-Eating monsters that denied even their final rest by the Emperor.
He swore then, to end the False Saint.
And unlike the failure of Herrion, Occanderael knew the plan to slay him. It was something simple, yet something the general failed to grasp. Simple, complete and utterly overwhelming force before which all strategy and tactics failed to matter.
In a stroke, they would slay the False Saint and bring the world to heel.