Some of you guys act as if it is ARC players' faults that ARC was OP before. Just because the class was OP doesn't mean it should be weak now. Don't be like that. It's childish.

To address the OP: ARC is not useless in the Ifrit fight. You just have to be better at timing your attacks because of the animation lock and reapply bloodletter just as soon as you can once it wears.