I agree 100% with Georgia Girl 2 — unfortunately, he’s never going to change. Honestly, if he’s as scary as you say he is, he’s possibly a danger to himself AND others. I’d be cautious if I were you.
I'm all ears, there! I don't think he's all that dangerous, but you never know what's really going on in someone's mind... Another reason not to let him move in with us, thanks.