So i was replaying the game, new save file and all that. I wanted to do all the main storylines as quick as possible, so that would me as few side characters as possible. I get to Jerid's route where Lila lives, and the mission where Mouar dies.
Logically, I thought this could be done by not letting her die in the mission (I usually just go through her path, but really didn't want to). I played that mission SO MUCH because her AI is, well, god awful. After much work I actually beat it without her dying.
Turns out, it doesn't matter. You HAVE to beat that mission in HER storyline, not Jerid's