Humanity fought a devastating war against an alien race known as the Dalki. To survive, humans unlocked and weaponized elemental "Abilities" from ancient books, eventually driving back the threat and establishing a militarized society built on power hierarchies. Those without abilities or low-level powers are treated as disposable lower-class citizens. Quinn Talbain is an orphaned, bullied high schooler who possesses no ability and is destined to be sent to the front lines as cannon fodder. Before departing for military academy, he receives a mysterious, dusty book left behind by his parents. Upon opening it, the book dissolves, and Quinn gains access to a mysterious "Vampire System"—a RPG-like interface that grants him stats, blood magic, and immense physical potential. The catch? He must consume human blood to survive, balance his extreme sunlight vulnerability, and conceal his dark powers from both the human military command and the ancient hidden factions of the real Vampire World.