In a world ruled by gods, demons, and mortals, the Demon King, once feared and revered, has met his end in an unfortunate twist of fate. However, death is not the end for this villain. A God, intrigued by the possibility of redemption, resurrects the Demon King and bestows upon him a system designed to force him into performing good deeds. But the Demon King is not one to be tamed easily.
Though he complies with the system's demands out of curiosity and for the power-ups it offers, his true nature as a villain remains unshaken. He continually defies the system, enduring its harsh punishments with the same unyielding spirit that once made him a terror on the battlefield. As he battles against the system, he also plots to destroy the God who cursed him with it.
Yet, along the way, something unexpected happens: the Demon King begins to form bonds with those he once considered beneath him. His cold heart starts to thaw, and he finds himself in a conflict far greater than the one against the system—a conflict between his villainous nature and the emerging emotions that challenge his very identity.