Demon King: "I hear that lately it's become fashionable to skillfully use useless cheat abilities and live a slow life in a rural village. Won't you introduce me to a fairy or someone who grants cheat powers?" Hero: "Go home!"

(Demon King Return Chronicle, Second Edition) The Demon King is dead. The Hero killed him. However. The Demon King was a being that repeatedly reincarnated infinitely by using corpses as vessels. As long as humanity existed, the Demon King would continue to resurrect endlessly. There was no way for humanity to destroy the Demon King until two hundred years later, when the Demon King's true body would resurrect. Fearing the Demon King's reincarnation into the pillars of the nation, the Church forbade the Hero from killing the Demon King carelessly. And so they decided to keep the Hero—humanity's trump card—locked away in an old castle deep in the mountains. Today too, the Demon King sneaks up to where that Hero is. ...Out of boredom!