Demons Bane: Ties That bind

This book begins with a sorcerer who, bound to a demon, breaks free of the mental control he’s lived under. He escapes the grasp of demons—only to take a group of teenagers from a camp on Earth and bring them back with him to the place where his demon master was weakest.
The teenagers are granted powers beyond their understanding and put into harm’s way to help them learn what abilities they have and how to use them. They’ll have to learn how to deal with old rivalries and build their existing relationships in order to work together.