For ages, humanity and demons have been locked in a relentless conflict, splitting the continent of Leunders into opposing sides. A fragile balance once existed between the two races, but that peace shatters when the new demon king launches a ruthless full-scale assault. Within a single year, every human nation falls to the invasion, leaving humanity's last hope pinned on a specialized team led by swordsman Kyle Leonard, whose mission is to kill the demon king and stop the war.
During this perilous mission, Kyle confronts the demon king and finds himself on the brink of death. Faced with the realization that everything he fought to protect is lost, a mysterious gem sends him back in time, before the conflict began. Armed with knowledge of the future and a fierce resolve to save those he loves, Kyle sets out on a path to grow stronger and prevent humanity's destruction.
