I have a hard time really caring much about Karlach...is there some way to change Karlach to be more evil? Right now the way I see it is she's not good for much more than a trial for Wyll and a bounty to collect in Act 1 that leads to a good sword and mage robe.
Karlach is pretty hard aligned to good. Hee whole schtick is that she’s wholesome and fun.
Sounds very boring...so bounty target is all she shall be...regrettable.
Each to their own, obviously you're inclined to more 'evil' aligned characters, but that doesn't make a good character boring.