Damn, so Faris deals damage by mutilating herself... but she can't naturally revive. Not particularly a skill that would be that useful without Licht around.
She clearly can't ressurect herself and looks like she doesn't have high regeneration (died instantly because of stomath wound)
So how did she gained high position in a dungeon if she can't fight? Sounds like plot hole. Reason for MC to take an active role in a fight.
@KamiKira00 She could be last resort suicide bomber for all we know. Assuming she's able to deflect any type of damage on her free will, she could easily take a OHK attack by the hero's party for Aria and wipe out the enemies at the cost of just herself. Plus the other 3 retainers might possess damage resistance spells to assist her too, we don't know about that now.