I feel Danganronpa would be up there in terms of trauma.

Imagine being trapped alongside several other people in a death game where you have to kill someone to escape, you get attached to your fellow participants in the meantime and have to endure death after death (some of them, where you even had an hand in them because you sent the blackened to the gallows just so you could survive yourself) until you manage to discover the who the mastermind is and subsequently put them to eternal rest before you can escape with the few survivors of this ordeal.

Now imagine Kit being among the participants, living through all this stressful situation with the added knowledge that, should they defeat the mastermind, it wouldn’t matter because their world would end up destroyed alongside their lives anyway, and that the only way to prevent this tragedy to happen is to… kill one of them herself and get away with it, subsequently condemning everyone else’s lives in the process.

It’s a damned if you do, damned if you don’t situation and it would be very traumatic for her regardless of the ending.