After the Holy Knights of Liones struggled to subdue the powerful Mela-galland, Tristan saved the day by unleashing his vicious Demon power. But just as they breathe a sigh of relief, an even greater enemy appears: And it's none other than the evil mastermind, King Arthur! Wielding his fearsome power, Arthur seems unbeatable. That is, until he's stopped in his tracks by Tristan's father, the king and legend known as Meliodas! Who will prevail in this epic battle of kings?!