A third option would be nice.
Just some comments from what the OP wrote:
I don’t think you can be forced to sell your soul to a fiend. It’s a conscious choice. That means Karlach may just be having “buyers remorse” which doesn’t make her all that much better than the fake followers of Tyr.
I agree the group didn’t kill the people living there. The former paladin even says they aren’t murderers. I think they just want to escape Zariel by bringing Karlach. Selfish but I didn’t see them as serial killers.
IMO they all suck.
