I`m wondering if your daughter`s ex could possibly have schizophrenia. Because the chaotic nature of that guy seems similar to how my SZ boyfriend acted at his worst pre-treatment stage. However the difference is that my bf was never mean, cruel or abusive, just behaved like a selfish, whiny child at times. He constantly said he thought that we weren`t meant to be together after I`d disagree with anything and refused to let him run the relationship by his whims. The ex could have very well had a psychotic break and was paranoid and delusional. He could also be bi polar. Just my opinion though, home this helps.