I wish I had some thoughts but, alas, I'm afraid I'm not a good resource for this sort of thing. The premise sounds interesting. I saw "Dangerous Liaisons" so I know of what you are speaking. It could be a tale of intricate play and counter-play. You'll have to decide if he has managed to learn any magic in those years. Decide if he gets double-crossed by someone whom he thinks he can trust. It sounds like it's full of opportunities! Good luck !