Why I Quit being the Demon King
Renuncié a ser el rey demonio / 마왕을 그만둔 이유, / The Reason Why I Quit Being the Demon King / Alasan Mengapa Aku Berhenti Jadi Raja Iblis / Mawang-eul Geumandun Iyu / Почему я оставил пост короля демонов / 魔王を辞めて勇者をプロデュースしてみた / 魔王退休計畫

After a war that nearly destroys humanity, the new Demon King abandons his role and leaves the demon realm. Demiourgos, the 666th Demon King, sets out on the run after declaring, “I quit being the Demon King.” Before him, a brave hero ends the invasion after Demiourgos’s predecessor crosses 665 realms and attacks the human realm. The hero’s divine sacrifice allows mankind to survive, and the story follows the runaway Demon King and a hero who becomes his subordinate.