That sounds like Lex. I knew him back home. He will put himself out to be your best friend, a humanitarian, a benefactor... only to turn the tables and pull all that away once he's done or if you reject him. And by reject, I mean protest any action on his part.
I hope you didn't give him too much magical info. It would be bad. You should be careful.. you could end up in one of his labs. Do you know anything about a boy named Arthur?