Hermione has already been trained to hate the color green, and the moment she sees it beginning to interfere with the ritual and feels the all-too familiar ache in her hand, she has her wand out and her guard up. She still isn't secure enough in her magic to be able to do anything quite so impressive as the other mages are doing, but she doesn't need to impress anyone. She just needs to help keep everyone else alive.

Right now, that seems to mean taking care of the rage demon, given that it's by far the largest thing on the field. She spares the wraiths a quick, wary glance, careful to make sure they don't cause more damage in their flailing than they otherwise might, before forcing herself to give the rage demon and her magic her full attention.

"Petrificus totalus!"

It doesn't work the way it should, never works the way it should, but she's fine with that. Even if it doesn't leave the demon fully paralyzed the way she'd intended, she's hoping that it will keep it still or at least slow it down long enough to make the other attacks on it that much more devastating. The faster they get rid of that thing, the faster they can pick off the smaller demons that are currently easier to deal with with hand-to-hand combat.