So there's like no way this is real, right? It has to be either a dream for him to realize he loves her and why his magic isn't working, a hallucination from his injury or someone like the sorcerer he got into a fight with on chapter 61 pretending to be shushu.
Whenever there's a broken anything in any story, the character can never just clean it up, they're guaranteed to cut themselves on it when they pick up the 2nd or 3rd piece, it's such an odd cliche.
I went into this thinking it was a split personality/DID thing, but a horny perverted ghost possession is definitely a choice.