Board Thread:General Discussion/@comment-2255188-20131110224813/@comment-8203434-20131112023157

I don't think he personally wants the key, I just think that he doesn't want his family to have it.

I think that he wants Nick around, so that he can claim to others that he has a Grimm under his control, possibly next time he'll use Nick rather than the Priest to remove those who disobey him.