14 years have passed since the battle with the Demon Clan. In the now peaceful Kingdom of Liones, Prince Tristan struggles to control the two massive powers he has inherited: the power of the Demon Clan from his father, Meliodas, who was the captain of the Seven Deadly Sins as the Dragon's Sin, and the power of the Goddess Clan from his mother, Elizabeth.
Meanwhile, the threat of Deathpierce, who was once renowned as a Holy Knight and member of the Pleiades of the Azure Sky before abandoning the kingdom, creeps closer to Elizabeth. In order to save his mother, who has been cursed, Tristan leaves the Kingdom and heads toward Edinburgh, where Deathpierce resides in a castle. When Tristan faces a crisis on the way, he is saved by Lancelot, the son of Ban, who was his father Meliodas' best friend and rival. Possessing different personalities and fighting styles, how will Tristan and Lancelot face Deathpierce, who wields the Staff of Chaos?
