My retainers are my strength. With a massive number of monsters appearing in a "Demon Wave," the group of small to medium-sized countries known as the Union of Eastern Nations faces a crisis. During a conference with Empress Maria of the Gran Chaos Empire, Souma is asked to dispatch reinforcements to the union. The place Souma sends those troops to is the Kingdom of Lastania. Which is where a former foe, the crown prince Souma once drove from the Principality of Amidonia, Julius, is putting up a hard fight as a visiting general . . . ?! And so, standing shoulder-to-shoulder with Julius, Souma uses his retainers' strength in an operation to save Lastania!