The World Bows Down Before My Flames Vol 4 novel

Homura and the girls cross the arid wastes with strict orders to bring the neighboring country of Zhorguan to its knees. If they succeed in their mission, Proto and Tsutsumi will finally be recognized as official Phalanx soldiers, so they have to see it through! The squad goes undercover, donning cursed collars to trick their foes and infiltrate the enemy town. However, unable to use magic, they soon find themselves in hot water. Proto steps up to protect those “feeble carbon lifeforms,” but disaster befalls her at every turn. A legendary earth serpent appears, beastmen invade, and her mechanical body shuts down! Will her warhammer of justice ever fall again?!