I would also be wondering if his ex-wife is narcissistic? I would be questioning why he has so much hatred. My Nmom is the only person on the planet that I struggled with feelings of extreme contempt for following my recent breakup, no contact, what I have been calling her "third divorce" just this time it wasn't a spouse, after the last straw of what she did to my family. We moved across the country to get away from her it was so bad. But thankfully, because I do meditation, utilize active forgiveness practices, because of my childhood, ect, I have been able to work through the feelings that I don't want to have. But, yes, if he hasn't come to a place where he has processed those feelings, at least he is aware of them, he should not go. It is very sad.