It seems they always have something to be angry about. At least in my situation, J has stopped (for the moment anywho) directing his anger towards me, but everyone else seems to irritate him, including, interestingly enough, OW and her children. Time will tell what happens.
I am constantly learning how to communicate with J. It isn't easy and it requires putting anger aside and dealing with J as if he were say a business associate. Courteous, kind, patient, but yet detached. It does help and it isn't easy. I don't know if it would work with your flaming fool of an XH. It helps in my sitch that J has cooled his jets somewhat towards me. He seems to be "proving" that he is just as good a dad as I am a mom. Not even close, but it's his illusion, not mine.
I am guessing the drama is a method of keeping you and the kids in his life. He needs you in his own sick and twisted way and when you put up a boundary he has a tantrum like a toddler, because he cannot figure out how to mend the bond the proper way. I think that is why J calls me every day and needs to come up with some whackadoodle reason to call/email/text me constantly.
Just be the better person that you have always been. Pray. It really helps.
WH
AT BD: WH 41, J 43; Bomb 2/5/2012 Two kids, one dog D Final 6/18/14 J marries OW 1/24/15 "No matter where you go, there you are"