Seventeen-year-old Elias Black is murdered by his own brother, only to awaken bound to an infernal contract with a mysterious demon. Equipped with the Devil's System, Elias hunts souls, masters forbidden abilities, and pursues retribution against those who destroyed him. Every power exacts a price—the devil's bargains always demand payment. As Elias grows stronger and forges dangerous alliances, a chilling truth unveils itself: his rebirth is merely part of a grand, sinister plan threatening existence itself.