In the wake of the Great Hall Tragedy, the continent of Atlatan descends into disorder after the collapse of peace between the Fantasia Union and the Factory Alliance. A surge of "Chaos," a malevolent dimensional force that spawns monsters and demons, disrupts the intended marriage of Sir Alexis Douse and Lady Marrine Kreische, resulting in the rise of the Demon Lord of Diabolos and the deaths of both archdukes, thereby extinguishing any prospect of harmony.
Siluca Meletes, a mage from the Factory Alliance, journeys across the ravaged land seeking instruction from a renowned magician. Along the way, she is rescued from Federation troops by Theo Cornaro, a young warrior armed with a mysterious "Crest" that can repel Chaos. Theo, unaffiliated with any territory, aspires to become a Lord to liberate his home, Sistina, from both a tyrannical ruler and the encroaching corruption. Inspired by Theo's noble ambitions, Siluca forms a magical pact with him, and together they set out to restore balance to their fractured world.