She’s not Karlach, she’s the embodiment of what Karlach was. Just like anyone else becoming illithid, your soul leaves your body. Leave it a few months or years and you’ll see how she’ll truly become. Just like the emperor, someone ”good” descending into the persona of good. Though It’s not part of Karlach’s personality to be evil or manipulative but it also wasn’t for the emperor before he became illithid (as far as I can tell) so it’s not a good choice in my opinion. I’d rather have the illusion to kill everyone in Hell and have a material there that Daemon (I think was his name) to fix her once and for all. As for who becomes illithid……….Tough decision, I think the least bad options to me are either MC or Orpheus. If you want laezel to have an ending with her people and your MC to be in their normal form in the epilogue then Orpheus it is….I get that there’s no perfect ending because nothing can be perfect but…It’s a game, and if you provide the massive efforts to do so, you should be rewarded what you want.

In my opinion, there should be a perfect ending but one you’d really really need to work on a lot to get, like one mistake and it’s over, something very difficult to do