Leo travels to another world, a sacrifice for a Dragon. At crisis, a System malfunctions, causing him to swap bodies with Princess Eve, the Black Dragon. Bound to the Soul King System, he learns an Apocalypse-Level Soul Tide arrives in one year; he must sign Soul Contracts with five powerful individuals. His contract with the Black Dragon Princess triggers a Ten-Thousandfold Return, turning Fireball into a Heavenly Inferno! Leo, in a Dragon's body, stages a 'hero versus dragon' spectacle.