Meliodas and his companions finally freed Liones from the threat that was weighing on the capital. At the same time, a shadow hovering over the forest of the King of the Fairies... King and Diane fall into a strange sleep and, when they wake up, they meet their ancestors, now members of the Ten Commandments, who invite them to pass a test to become more powerful! The young King of the Fairies and the giant will then witness the Holy War that took place three thousand years earlier!