Saikyou Yuusha wa Oharaibako→Maou ni Nattara Zutto Ore no Musou Turn  

Saikyou Yuusha wa Oharaibako kara no Maou ni Nattara Zutto Ore no Musou Turn, 最強勇者はお払い箱→魔王になったらずっと俺の無双ターン

In Midterria, Garrius has defeated the demon king and saved humanity from their threat. Although he may have felt uncertain after speaking with an old lizard, his deed was done and the demons were vanquished. However, there was a small hitch in his homecoming. When he finally met King Edgar, it was revealed that someone else would receive credit for all of Garrius' triumphs. The king also ordered him to be banished from the kingdom. Instead of fighting this unfair plot, Garrius decided to leave and find a new life for himself. While doing so, he hoped to clear up any doubts he had about the true nature of evil demonkind.

Saikyou Yuusha wa Oharaibako→Maou ni Nattara Zutto Ore no Musou Turn began as a web novel on Shousetsuka ni Narou on December 13, 2017. The first official volume was published on June 1, 2018 by Kodansha under the K Ranobe Books label.