SO I finally finished a playthrough, and I chose the ending that me and Minthara were planning all along (it was even in my journal):
dominate the brain for ourselves.
But the end cinematic was so dissatisfying, I wonder if this was the "good" ending for Minthara. It looked like I mind controlled everyone, even Minthara.
I loaded back the game before I made this choice, and chose to destroy the brain. Now I got a way longer ending, and even Minthara was in it, saying this was the best outcome, that we were going to conquer the underdark together.
Isn't this a bit weird? She literally said to me: don't destroy it, bend it to your will! right before the killing blow on the boss. The game is working you towards dominating the brain if you romance Minthara, but that ending is actually quite awful for her, as she ends up being mind controlled yet again.
Also that ending was very dissastisfying, you just get a shot of your party on top of the
and that's it? Is it a bug where something else isn't triggered correctly or is this the way it is intended?