In a distant era, the legendary dragon Bahamut unleashed chaos upon Mistarcia, a realm where gods and demons coexist alongside humans. To avert catastrophe, divine foes united to seal Bahamut by splitting the key. With the world out of immediate danger, bounty hunter Favaro Leone relishes his carefree existence, evading his pursuer Kaisar Lidfard. However, Favaro's routine is disrupted when he crosses paths with Amira, in possession of half the key crucial to peace. Amidst this turmoil, Shingeki no Bahamut: Genesis follows an unlikely band of heroes navigating the turbulent clash between celestial and infernal forces, forging their destinies in the brewing tempest.