So you, you're... [HOOOOOOLY SHIT. now he feels super dumb because shouldn't he have made the connection a little earlier??] Wow, okay, that explains some things. A lot of things.
[But then he shakes his head a little, almost to clear his thoughts, to focus on the important here.] Okay, so, you can change him-- I'm pretty sure it'll work, because you're still a supernatural being and not a human, so that would change the body enough to force him out.