I was probably overlevelled, but if I remember right the 2 factors in the fight is willpower to resist her seduction and maybe use some items to regain energy from her sleep stuff.
If you have the kotone like curse or whatever than I believe ur fucked because I believe that curse reduce your willpower roll (I maybe wrong) and if you have like to grapple her or magical restraint use that and penetration skill to the butt
