Death March to the Parallel World Rhapsody, Vol. 20 (light novel)

"After a tip-off from a blue-haired goddess of a girl, it's off to Parion Province for Satou and the party! There, they run into Hayato the Hero, who appears to be suffering the virulent effects of a curse from a demon lord! Defeating the demon lord and curing Hayato's affliction will be no easy task, however. This foe possesses the ability to manipulate their domain at will. But a few armor and weapon upgrades later, Satou and the girls as well as soldiers from both the Saga Empire and Parion Province are ready to take this demon to task!"--