The Demon King Diablo is back as... God? A fateful encounter with the High Priest Lumachina Weselia finds Diablo and his party accompanying this mysterious stranger on a journey to cleanse the Church of its corruption. Believed to be God by Lumachina, Diablo eventually decides to protect her on her initial quest to find the head paladin, the virtuous Batutta.

Diablo, Rem, Shera and Lumachina are joined by the grasswalker, Horn and the Magmatic Maid, Rose. Will Diablo fulfil Lumachina's wish? And can the Demon Lord from Another World truly play the role of God?