Having saved the Grenflare Empire from the threat of the Infernal Demonic Beast, Eugene returns to the Lykeion Magic Academy just in time for the school festival. It’s time to tour the food stalls with Sumire and Sara and participate in the widely anticipated Unity Tournament. However, the festivities come to a screeching halt when reports of massive hordes of monsters going berserk within Babel start pouring in. To make matters worse, the mysterious Dungeon Master announces a new Deus Discipline! The only way for Eugene to survive these new dangers is to accept a new power from Demon Queen Eri.