The continent of Atlatan once again finds itself devoured by the flames of war after a horrific event known as the Great Hall Tragedy. What was supposed to be a joyful occasion that would establish peace between the Fantasia Union and the Factory Alliance, the marriage of Sir Alexis Douse and Lady Marrine Kreische, was instead a tragedy. As the bride and groom walked down the aisle, the ceremony was suddenly interrupted by a powerful convergence of "Chaos," a dark energy from another dimension that corrupts the land and brings forth monsters and demons into the world. From within that energy appeared the Demon Lord of Diabolos, an evil being who instantly murdered the archdukes of both factions, shattering any hope for peace between them.