In a world where Hunters fight monsters to protect humanity, Sung Jinwoo, the weakest Hunter, struggles to survive. After barely escaping a deadly dungeon, he is chosen by a mysterious System that grants him the unique ability to level up, unlike other Hunters whose powers are fixed. As Jinwoo grows stronger, he battles enemies, both human and monstrous, while uncovering the secrets of the dungeons. Eventually, he learns that he has been chosen as the Shadow Monarch, a powerful necromancer who commands the dead, and becomes humanity’s last hope against the other Monarchs who seek its destruction.