Fan Casting We Can Fix Him (No Really We Can)

This is my and my friends' dungeons and dragons campaign. It's set in an alternate universe Hogwarts during the early 1940s - when Tom Riddle, still a student, is making his first big foray into the dark arts. Our job as students and professors is to find him out, and stop him before he causes irrevocable damage to the Wizarding World, but what's the catch? Tom Riddle and his friends are perfectly charming, and a couple of us have fallen... hard.