Originally Posted by Raidzu
I mean when we ask her, after Raphael battle, why doesn`t she go to the House of Hope, she said: "Because i don`t wanna go back to Avernus no matter what!" And that`s all. But now she accept returning as an option, so why now we can`t convince her go to House of Hope? It`s a good ending! Yes not 100% good, but still good. She will be living in the big rich mansion, that hides somewhere in Avernus, so even archdemons cant find it. In this mansion exist a many portals to main capital citys, even in Baldurs Gate, so she can go there whenever she wants, and get back when engine is overheating. And she is under protection of Hope - not a devil or demon but happy, funny dwarf!
With House of Hope exist, there never be 100% tragedy endings for her as logical option at all.

Never thought about it this way, but as she
Feels better in the House of Hope and then noone of Zariel servants appear even after Rafael is defeated it definitely means that Karlach is pretty much safe there, but... By the end of the game her engine is pretty much exhausted so she can't stay in Faerun anymore, then if we imagine that she moves in the House of Hope it seems to become her prison forever. Not a happy ending tbh.