Not only it deletes purpose of her character and questline, but also deletes purpose of RPG. I honestly have no idea how many times do I have to repeat it, character being doomed in RPG just because, is a trash writing (actually character being doomed in RPG is trash writing, period), even more trash if she's the only one who's doomed, EVEN more trash if her issue is literally the easiest to fix lore wise. Even Astarion has some resemblance of good ending, unlike Karlach you actually can look for a cure together, instead of cosplaying call of duty zombies, while devs call this bullshit "ending she deserves"
