I have enthralled the Moth Priest, cool beans.
However Upon returning to castle Volkahirr all the Vamps attack the priest...has anyone else experienced this/have a way to fix this glitch. I can not talk to anyone because every 5 seconds they have to relentlessly beat the monk to his knees again.

My friend had this problem, except the Ancestor Moth would attack everyone else. You should be able to calm him with Vampire's Seduction, I believe that's what my friend did.

I had this problem at fort dawngard, I had to replay the saving him quest to findout what went wrong. turns out I had to beat him up to break the vampires hold on him.