Dude, what are you talking about? Flandre IS a blood thirsty, mentally deranged vampire. Not in the rabid sense, but she can pop you like a tomato, at a moment's will. Hell, she destroyed a freaking meteor in a matter of seconds, because she was bored. She couldn't even talk in coherent sentences, when she was talking to Aya in an interview & Aya said herself, that she was basically getting nowhere with her.