

As the Monster Age arrived and special abilities awakened, what awaited humanity was the end of the world. At the brink of the apocalypse, Frank Channing was sent back in time to the second year of the Monster Age. There, he awakened the Infinite Devouring System, allowing him to gain growth points by hunting the monsters. Along with it came a mysterious serpent-shaped mark on his arm. It could transform him into a powerful serpentine creature capable of wielding the very forces of the monster—seemingly tied to the secrets of the Blood Moon. From the system, Frank learned that he carried the mission of saving the world.

Underworld boss Yara Jenkins dies saving Nina Shaw from a push off a building and wakes up in Nina's body. Hoping to leave her violent past behind and attend college, she discovers she's the school's worst student—and that Nina was bullied by the Shaw family's fake heiress and the entire household.Yara strikes back ruthlessly, crushes the Shaws, and reunites with her former right-hand men. But her exiled sister is secretly returning, vowing to seize power.