Due to a rare act of kindness on her part, 24-year-old Yoon Kiom lands in the absurd role of acting as a sacrifice in a demon summoning ritual. She gets her hopes up when an inhumanly strong being interrupts the proceedings—blasting through the wall against a backdrop of dazzling light—but she is too quick to assume that the stranger has any intention to save her. He calls her by a strange name, Sion, and seems bothered by the mere sight of her. Kiom admits that the man is very handsome, appearing like an avenging angel with his sword drawn. However, she also wonders what evil she has committed in her lifetime for an angel to earnestly state that he plans to kill her. [Written by MAL Rewrite]