Following the wishes of her master, Blood Demon, Il-hwa destroys the Namgung clan, but as she faces death, she hears a shocking revelation due to Blood Demon's betrayal. “Now, you are the only Namgung left in the world.” Il-hwa learns that she was the long-lost child of the Namgung clan, Seol-hwa, and that she was raised for Blood Demon's evil schemes. Having returned to her thirteen-year-old self from a tragic death, Il-hwa — or rather, Namgung Seol-hwa — realizes that an opportunity to change the future has arrived and takes steps to prevent the Namgung clan's annihilation. Will Seol-hwa succeed in stopping the Blood Demon from annihilating her clan and achieving revenge?