Immune to Status
Sleep, Return, Confusion, Silence, Transform, Berserk, Stone, Slowly Stone, Manipulate
She's not so tough, really. Equipping a Jem Ring will keep you from being paralyzed by her Stare Down attack and make your life a lot easier. Start with a dose of Barrier and Haste, and since she moves so slow, it'll be that much easier. Anything goes as far as attacks, too, so just unload everything on her and watch her fall.