er saving Gladstone and dispatching the belligerent monsters in the Underground Labyrinth, Aria and her friends have cemented themselves as heroes. The weary crew has no time for a catnap, though. Upon their return from the labyrinth, the party is surprised with a summons from the Emperor of Aushura himself! But his invite isn't for a simple reception--it's a request to work with the empire and a band of legendary heroes to take down their most dangerous enemies yet: the Four Demon Beasts!