Arthur's battle with Cath comes to an epic conclusion. The Seven Deadly Sins go their separate ways as peace returns to the world once again.
A vicious beast in his true form, Cath attacks the reawakened Arthur. Now separated from the Sins, Merlin attempts to take on the monster herself.
The Sins are shocked by Merlin's longtime deception. Meanwhile, Merlin declares that Arthur has been recognized as the King of Chaos.
The long-fought Holy War comes to a dramatic end. Peace returns to the Kingdom of Britannia once again, but a new threat looms on the horizon.
Zeldris and the Sins corner the Demon King in both realms, but the King separates from his son's body and possesses Britannia itself as his new vessel.
Escanor converts all of his life energy into magic to defeat the Demon King. Meliodas pleads with his comrade to stop, but Escanor refuses to listen.
Diane destroys the source of the Demon King's magic. Meanwhile, Escanor continues fighting the Demon King at full power, exceeding his limits.
With Escanor's aid, Meliodas and Gowther reach the spirit world, where they aim to split the Demon King and Zeldris back into their own bodies.
Elizabeth and Meliodas face the Demon King, who now possesses the body of Zeldris. Meanwhile, the Sins clash with a beast summoned by the Demon King.
Merlin rescues Elizabeth, who barely evades a falling boulder on her way to the Demon Realm with Meliodas. The Sins realise the Demon King is alive.
Now that Meliodas is the Demon King, he cannot remain on earth. Though his friends acknowledge his fate, they are unable to accept it.
Peace returns to the Kingdom of Liones. Although Elizabeth is still under a curse, Meliodas assures her there is a way to break it.
Escaping purgatory, Ban faces the Demon King, who now possesses Meliodas’ body. Elizabeth and the others make their way into the spirit world.
Merlin's spell thwarts Meliodas' transformation. The Holy War seems to be over, but Elizabeth senses something is still terribly wrong.
As Meliodas absorbs every last one of the Ten Commandments, Merlin attempts a forbidden spell to stop the birth of a new Demon King.
Chandler and Cusack merge to form the all-powerful Original Demon. Merlin gives up any hope of victory, but Mael and King soon come to her aid.
Meliodas and the others have to defeat the Demon King before they can escape Purgatory and make their way to the world of the living.
Mael changes form after absorbing four of the Commandments. King soon overwhelms him with his Spirit Spear, but Gowther tries to save the Archangel.
Gowther takes on Mael to protect his friends. Diane also joins the battle, but the Archangel's power level continues to rise as he nears his final form.
Gowther reveals that his creator, the real Gowther, cast a forbidden spell on Mael and all those who knew him to end the Holy War 3,000 years ago.
Meliodas grapples with suddenly losing his memories of Estarossa. Zeldris, Chandler and Cusack threaten to overpower Merlin and the others.
With Wild now an ally, Meliodas brings Zeldris' tragic past to light as the newly formed trio make their way towards the Demon King.
Reunited once again, Ban and Meliodas prepare to face the Demon King, who they suspect holds the key to their escape from purgatory.
Ban searches purgatory for Meliodas. King, Deriri and the others head to Heaven's Theater to rescue Elizabeth, who's been abducted by Estarossa.
