Ayase

but that is because Aihara Family work. Her origin is a curse from Byakko after Byakko killed by Kamiizumi's swordsman using a katana that forged by Sanjou blacksmith and blessed with spiritual power to become spirit sword by Aihara's shrine maiden at that time. Later that curse weakened by Aihara's shrine maiden and sealed to iron mirror as a guardian deity for Sanjou Family. But not all curse can sealed to iron mirror, the proof is like curse in Touki's body, that later named herself as Magatsumi though she said that she didn't have a name