After saving the world, the most powerful hero, Leo, has become unwelcome in the tranquil human world. He was far too powerful. He's been exiled and is looking for work with the Demon King's Army, which he vanquished and now has to be rebuilt. The Army faced a number of issues, including too much work, budgetary difficulties, and so on. Leo begins to use his abilities to improve things. Leo runs across Echidna again and inquires about her invasion of the human realm. There was an unexpected twist in the narrative...