What if Grey's mother was a nun? Given the evil proclivities of skinwalkers, I could imagine one raping a nun and impregnating her in order to torture her. Having her know that her child was the offspring of a monster, but not believing in abortion (or perhaps abortion didn't exist back then) she would have to carry the child.
What if she decided to raise the scion to be good? Naming him Goodman as a constant reminder to him. Remember, he did the job for Harry for $1 iirc. What if the "rent" he was paying was his saintly mother?
Torn between and evil father and a saintly mother, he is a mix of both.