Arifureta: From Commonplace to World's Strongest (Manga) Vol. 6

Hajime and his companions have returned to the town of Ur, where a horde of demons looms just over the horizon. The town might not mean anything to him, but after hearing a heartfelt plea from his old teacher, Hajime decides to try saving it. Bolstered by the overwhelming power of the dragonborn princess, Tio, Hajime's party stands against an entire army all by themselves!