Okay, I can add in something to make it more clear, that's fine.  As for IC motivation I can add something in but it amounts to something similar to a Paladin's instinctive call to fight evil.  I'll expand on it in his background but one of the prestige classes I was interested in was Mortal Usher.  There were others as well, he's sadly going to be all over the place, but I'll add more to the background.