My godness I've been scrolling through this thread for a few day now and my god what an ungrateful bunch you are. Karlach is supposed to be a doomed character, I don't know why you just wont accept it. By god Larian even rushed and added new cutscene just for her, and it's still not enough for you. Clearly there was no plans for her to have a good ending, and it becomes obvious when you listen to devs. They seem to be happy with her story as it is, they think its the fate she deserves and thats it, its their story they can do whatever they want. Just accept it
