Just use shadowbound. Once she grapples you keep attacking and don't let her set u free. You will keep damaging her and shadow bound will not let u die since the entire grapple move counts 1 turnEvery time I get Rosita down to 2 or so hits I make sure I fully heal and she still 1 hit kills me, it's stupid. Can somebody please just post a save where you beat her and submit please.