Tom came from a troubled family. He was conceived by magic through a love potion, so he was never truly loved. His mother died in child birth and he never met his father, who had no wish to know him. He felt isolated with no one to talk to about his powers. The the orphanage everyone kept a distinct distance from him. They thought he was strange. This made Tom resentful of people in general. When he got angry, odd things happened. Fires started around him frequently. Eventually he realised that he was responsible and became able to control it. Control was something he had never had before. People had always made the decisions for him. Now here was something he controlled. He wanted to know more, and when he went to Hogwarts learnt as much as he could. But he didn't like the constraints. You couldn't do this with magic and you couldn't do that. Tom didn't want to be bossed around any more. He was going to do things his way. It led him down a slippery path. The lure of being able to do what he liked got to him and he eventually lost all care about others. He just wanted power.

Bryony/Slytherin.