Sounds great to me! I'm not 100% sure how the event is going to be framed, but if he sees ghosts of his past (which I think is being implied? I can't tell), his PTSD is very, very likely to come to light. I'm sure we can come up with something either way. Theon isn't easy to make friends with, but he seems to form the "hey, you're adopted now" CR pretty well, oddly enough.