What is the grip that is holding him to this relationship? It could be more than fear of her violent behavior. Abuse situations are very individualized. Emotional and physical abuse is very complicated because the victim is emotionally involved, not only in the present, but from something going on deep within. The bottom line is fear. Fear of something.And I'm willing to bet that he is going through his own torment.
The thing is, that only he can make the decision. Only he can make the move. Nobody can do this for him. Nobody can make it okay. Others are there for support and love. But it is he who must take that step to move away and reach out.And then the healing process begins.