J.D. Appleton

J.D. Appleton was a Witch turned lower-level demon, who made a deal with another demon, Corbin. The deal was that J.D. would get close to Cassandra Halliwell, in exchange for powers. He dated Cass for a while before he was vanquished.

Growing Up
J.D. was born to a witch, Mrs. Appleton, who taught him to be good and pure. She enrolled him in Magic School to ensure that he grew up as a good witch. It is mentioned that J.D. left Magic School when he turned eighteen because he wasn't developing any powers. That is presumably when he made the deal with Corbin.

Deal with Corbin
Anxious to be more than he was, J.D. struck a deal with a demon named Corbin. J.D. would spy on and get information about Cassandra Halliwell. He would then pass that information onto Corbin in exchange for a new power.

Personality
It is mentioned by his mother that J.D. used to be a good person. Kind, caring, and helpful towards others. But after he made his deal with Corbin, he changed. He starting to get dark, moody and closed off. Those around him started to act differently as well. He has a very manipulative side, as he was able to convince Cassandra - one of the purest witches, to use her powers for personal gain. He then convinced her to use her to beam them into a car and steal it. He became fixated on Prue, wanting nothing more than to make her pay for coming in between him and Cassandra.