"I didn't find a body before I fell, that's what I'm trying to fucking say!" Don't you tell him to calm down when you're threatening to cross him with holy water or execute him. "Look, I was in a robot body, then I hitched an entirely consensual ride in someone else, then I hopped into another brain not to take him over or anything, and now I'm here and I'm in a human body that seems to be my own, cuz I sure don't feel any other assholes knocking around up in my head. Booooo, I'm a ghooooost, I'm not gonna fucking haunt your ass unless you give me a reason to."

Huff. Puff. "And you're starting to give me a reason to."

Not that he knows if he can hop around like he used to or not. Maybe don't try it right now.