Thank you for sharing your experiences. He's been in counseling, but it really doesn't seem to do anything but give him a place to make up a more grandiose world. In fact his therapist encouraged him to talk to my daughter about having another child, so my guess is she doesn't even know that they're separated (because who would encourage that if they knew?) and clearly doesn't know that it's a risk to her health. Either way, you're right, it really is a mental illness and the way you describe "lives in his own fantasy land in which he somehow both the hero and the victim" is exactly spot on.