I think talking to them might have changed. I just finished the fight 15 minutes ago, and they came to her aid. I killed Auntie with a fireball and they all remained hostile. I am not sure if was changed or if it was my strategy.
Might this have been an instance of this problem ….
(Though if you kill Ethel too quickly to see her surrender speech, they’ll stay hostile and you’ll have to run away and come back before they’ll calm down and speak, which I think is a bug.)
If Ethel starts her turn on (maybe) 20 or less HP she’ll try to bargain with you, but turning her down and killing her should turn the masks neutral. But if she never starts her turn with low HP because you kill her too quickly then the masks stay hostile. I had my party flee to the fairy ring in the back room, and if they all went through it, ending combat, and came back then the masks were neutral again,