He was a demon. He wasn't going to let her in on how she could get her soul back. That would give her a bit of an edge and he wasn't sure that he wanted her to have that much. There were of course ways but she would have to find them. Or at least find a way to make him talk.
He looked thoughtful for a moment before a slow grin came to his face. "I would have a mortal body and some rather nasty otherworldly powers. I could do just about anything I wanted."