An idea for a Spooky.
Your character was formerly possessed at one point. The entity used your body to fuel several powers. You were exorcised and seem normal for a while but then weird stuff continues happening. Worried you might be possessed again, you got help and were told that you weren’t possessed but that your body, mind and soul remember how to do the supernatural things the possessor used you to perform.
Basically the idea that lost power can always come back but being afflicted with power you don’t understand enough to control is exceptionally dangerous.