Magane Chikujouin

An antagonist from the light novel and anime series "Record of the Night Window Demon" (Yasou Kiroku). She puts on the guise of a sarcastic high school student, but is really a psychotic murderer who enjoys toying with others' emotions and shows no remorse towards killing innocents. She possesses an ability called "Infinite Deception of Words" that allows her to bend reality through lies and deception; by telling a lie and manipulating somebody into rejecting that claim, it creates a "lie of a lie" which by proxy makes the initial claim become real. She chooses to remain independent from either faction.

(Source: Wikipedia)