You're a sorcerer who summons (shapeshifts) one's being to create another and fuse that energy/strength/skill to who you chose to manipulate.

One night at Shibuya, you shapeshifted an ally to be Toji who died before. He conquered the power of the person and consumed his entire being, turning him to be himself in the form of another's body dominated by his own. You two had this silent moment as you both stared into eachother's eyes out of disbelief, yet he leaves a sly smirk