
Technically, he possessed the body so Claude’s older brother soul is still around. That was the one who was being nice to jenette. When he refused to use Jeanette anymore, that’s when the wizard possessing his body completely took over. That’s who we are seeing now. And what I just said wasn’t a spoiler so don’t worry.

I’ve been thinking about that too. Whether the magician and Anastacius made a deal and are kinda both living inside that body or if the magician completely took over.
What’s also got me wondering is that flashback we got with little Claude calling for Anastacius and he’s standing there looking up at the wall like possessed. Was he "seduced" by a black magician/that Aeternitas guy when he was young, leading to them working together or what is it???
That story behind the real story is so interesting too, I almost dare to call the author a genius (づ ̄ ³ ̄)づ
He is not real anastacius, he is just wizard who use anastacius body so if lucas see it he will immediately recognised it.