I think that evil should not be unambiguous, and some good moments should even be on the path of evil, if not talking about absolute chaotic evil.
Let Kagha tell us that thanks to our cruel decision to help her with the tieflings, the druids were able to maintain their independence and avoid problems with the goblins, organize a celebraty party with the druids for us that will leave good feelings.
Let Minthara see that MC can be a true friend she can trust, who won't stick a knife in her back for Lolth, the Absolute, or anyone else.
Let the fake paladins of Tyr tell us that the infernal legions are grateful to us, and perhaps offer cooperation in the future. Now there is no reason to kill Karlach, it leaves a bad feeling that we are getting nothing morally for it.
Show the paladin leader as a difficult person who will tell about his difficult fate which made him serve evil, so that we feel sorry for him no less than Karlach.
And so on, I think you understand what I mean
