So, I felt the need to omakeify Xavier's defeat of the daemon prince. I felt like rather than a bare victory, the reason he came close to death was more because of pushing too far. Maybe give a bonus to his roll for traits and/or making the daemon prince perma-dead in canon from this I guess if I had to pick?
Cat and Mouse
Right now, Gerald Xavier was the calmest he had been in the past few days. Ever since Henry had been killed by those damn invaders, he had been having trouble keeping it together. In both a personal and professional sense, Henry had been a keystone of the defense. Henry's command ability, as well as encyclopedic knowledge of the resources they had available and amazing organizational skills, had allowed Xavier to focus almost entirely on tactical command and combat. On a personal level, Xavier had been very glad to be able to relax with one of the few people who didn't view him as essentially a demi-god and the right hand of Rotbart. One of the few people who he counted as family, like Syr, Frederick, and Mittens. But now not only did he lose that outlet from the constant stresses of combat and command, as well as a large margin of his flexibility in command duties, but he had the knowledge that his brother in all but name was dead haunting him whenever he tried to rest.
But now he was not resting. He was engaged in a deadly game of cat and mouse with a daemon prince, one of the greatest traitors to humanity in existence. His doubts and worries were faded, his mind engaged in this far more immediate struggle. It was never more engaging playing these games of cat and mouse with another predator. He would say fellow predator, but he would never claim kinship to those foul beings who discarded their humanity and turned traitor for power.
In games like these, you never really knew who was cat and who was mouse. Oh, you might believe yourself to be the cat through the entire fight, but there could be no certainty. Many a daemon and chaotic psyker he had faced before this believed themselves to be the cat right up until their destruction, each dying with a surprised look upon their face as they realized that they had never been in control of the fight at all.
Had it been years ago, back when he had faced the so-called Angel of Betrayal, he had no doubt he would have been the mouse. He had been good, very good, but that fight had knocked the arrogance out of him before it could truly take root just as much as the intervening years had improved his skills. Now he knew that it was not immutable fact that one was the predator and one the prey. No, one lucky blow, one miscalculation, and fortunes would be flipped.
But still, right now he knew he was predator. The daemon prince believed him to have been finally trapped in illusion, and was even now preparing to move in and defeat him. But it had neglected his connection to Mittens—while it might have temporarily succeeded in ensnaring him, it had neglected that he had an entirely separate viewpoint to draw upon, perhaps because he had been careful to avoid having Mittens make an appearance in this fight.
As he drew forward to end this charade and send this foul traitor to humanity and the Emperor back into the warp to beg forgiveness from its masters, however, everything changed. This, this THING dared to taunt him with the death of Henry? It DARED to disparage his memory, claim that it would hunt down his soul within the warp and take it?
No, simple disincorporation would never do for this THING. It would know pain, it would know fear, and it would know death. True death, the kind it had sought to evade with its betrayal to mankind. Drawing far more deeply upon his power than was safe, Xavier SLAMMED down upon the being's manifestation, holding it in place. Stalking forward, rage in his eyes and heart, he swung, dismembering it while burning it with fire strong enough that the wounds left could never regenerate. And then, once he saw the understanding and terror in its eyes, he pulled deeper still upon the warp and burned it down to its very soul, and then burned that. There would be no returning to the warp for this foul thing.
Turning back up, he saw the hordes the daemon prince had commanded, and he saw their fear. In his fury, just destroying their prince was no longer enough. So he turned his power outwards, and commanded them all to burn.
Some minutes later, Xavier came back to his senses. Here he was, exposed, exhausted, and vulnerable. Luckily, none had taken advantage of his slip—perhaps the daemons had been too eager to get away, or perhaps they had not noticed that he was exhausting himself and using levels of power that were dangerous even to him. Quickly, he gathered himself and returned to the heavily damaged university. It looked like they would be safe, a traitor to humanity had suffered final death, he had lived, and Henry was avenged. It was an acceptable result. But still, he chided himself not to lose himself to vengeance like that next time a person he cared about died. Or if he felt the need to do it again, at least not to be such a damn fool about it. Rotbart came far too close to losing both of his pseudo-sons to that daemon.