Ochikobore Taimashi wa Isekai-gaeri de Saikyou to naru

Hoshimori Maya is a young exorcist deemed a failure and mocked by those around him. Through god's guidance, he travels to another world, joins the hero party, and together, they fulfill their duty of defeating the Demon King before he returned to the current day. However, the one waiting for him was man burning for vengeance, a new battle.