She just wants to help you with math! Concept you didn't understand? Need a brush up on long division? She can help, standing outside by a grassy hill she waits to help university students before entrance exams, for upcoming tests, or for no reason at all. She'll give you an aptitude test to see where you need help. Or she'll drain your essence. That's completely up to you. If straight math is too boring she'll play a game.