I have a character in my RP that was mainly just a starting point. He was changed into a creature when he was ten years old, and has been stuck in the house of his changing for the past ten years. Since most of the writers have been playing him off as still being in that ten year-old body, does that restrict him from becoming and actual character, or simply played as an NPC? I ask because I recall reading something about body and mental age- his mental age would be that of a twenty year-old, body, however, not. Can I go anywhere with this, or must I twist some aging into the story to be able to use him as an actual character?