Writing up a post now and [@Renny], you know that Xavier isn't actually in the armor right, nor does it have his face. The armor is part of his new Curse, which he got from awakening his demon blood, that allows him to summon demonized souls of either Beasts, Magical Creatures, or even people(though those have to be willing subjects). Normally, he has to kill something to get the soul, but I've given him access to 3 basic souls, Cassandra, HIs rook, and his Knight, who Renji was fighting, kinda. The curse also allows one to possess either a Knight or a King, or vice versa, allowing you to gain partial access to their own skills. Basically, Renji was fighting, and pwning, a slightly buffed Xavier that couldn't be killed. In my next post, he'll lose Xavier's Tephra God Slayer MAgic, but he'll gain access to his true skills as a master swordsman. I plan to explain his backstory in IC. The blue energy and the Knightmare rush are just the basic abilities granted to the KNight role.