The issue I have with Wyll, is that if you kill Karlach, you can tell him it was the right thing to do, and he accepts it, seemingly. But next night, when Mizora pops up, he acts indignant and not at all happy. It's odd - even if he's not present when you confront with Karlach, and he has no way to see that she's actually nice, he still argues over her like he committed a crime - even though he shouldn't be. We just went "Hail the blade of Frontiers!" over Karlach's death just five minutes ago, and now he's like "We killed an innocent person, you tricked me!".
Besides, how does he know she's innocent. She acts nice, but surely, no one is naive enough to just decide "ah, this DEVIL-ALIGNED person who is nice and friendly is being genuine" right away?
