Using the Cleric's control undead on a Vampire MPC seems to ignore the character's will saves and auto dominate them. Vampire's class is Hexblade and I've failed 1 DP which has impacted my saves slightly for various things, though that shouldn't matter as Control Undead does not prompt a save at all. Other will saves seem to work fine.
Additionally, I had protection vs. Alignment up on my PC, though as she is undead I don't think that it works against Necromancy "mind-affacting" spells.
We replicated this twice, once finding out in the middle of a fight that it happened and then finding out through OOC testing. It just automatically adds the undead to the party. I'm not sure it is related to MPCs, vampires, or otherwise.
