Isn't Philippe August in a great place to be an antagonist? He has a purpose, she doesn't understand it, but he sets before her all these tests which may or may not reveal things she wants to know.

Other than that, are you looking for whoever kidnapped her mother and leads the Shadow Guards?
Facing a bitter heart could make her friends antagonists.

There's more in there. Going to keep thinking about the right questions to ask you to bring it out.