Dungeon Builder: The Demon King's Labyrinth is a Modern City! (Manga) Vol. 5

Procel's dungeon utopia is threatened by the greed of their neighbors, but it's up to Wight to defend them. Whether he's up against a human or a demon lord, he must use all of his tactical skills to defend the peace of their dungeon. But fierce battles bring with them bitter losses--will the price of this dungeon war be worth it in the end?