A Middle-Aged Hero, Betrayed by His Favourite Pupil, Is Revived as History's Strongest Demon Lord,Manadeshi ni Uragira Rete Shinda Ossan Yūsha, Shijō Saikyō no Maō to Shite Ikikaeru,The Betrayed Hero Who Was Reincarnated as the Strongest Demon Lord,The Ex-Hero Who Resurrected as the Most Powerful Demon Lord,The Old Hero Who Died After Being Betrayed by His Student Was Reborn as the Strongest Demon Lord in History,愛弟子に裏切られて死んだおっさん勇者、史上最強の魔王として生き返る,被愛徒背叛而喪命的勇者大叔，作為史上最強魔王復活,被爱徒背叛而丧命的勇者大叔，作为史上最强魔王复活,애제자에 배신당해 죽은 아저씨 용사, 사상 최강의 마왕으로서 되살아나다