Meliodas, Ban & Wild vs. Demon King

Meliodas, Ban & Wild vs. Demon King is a battle between Meliodas, Ban and Wild against and Demon King in Purgatory.

Prologue
After meeting Wild, the pig-like creature agrees to take them to find the Demon King on the condition that he can escape alongside them before taking them to his home to avoid a hot sandstorm.

Inside, Meliodas and Ban tell Wild about Hawk, much to his surprise but is nonetheless relieved to know his younger brother is doing alright, making Meliodas remember Zeldris and he tells Wild and Ban about how their relationship soured, but upon trying to remember Estarossa, Meliodas begins to notice how his memories of his second brother seem to be fluctuating.

A voice begins to agree with him stating that it doesn't remember anything about Estarossa either and the three are shocked to realize that the Demon King himself has appeared before them.

Battle
The three are surprised to see the Demon King himself has found them, to Meliodas reacting in anger and shock, Ban surprised by his size, and Wild explaining that he continues to absorb the life energy of the creatures of Purgatory to maintain his power within the realm.

The Demon King himself tells that he is surprised that Meliodas has regained his sanity and understands that Wild, whom he refers to as a "rare beast" has told them of the door out of Purgatory which led them to him, but Wild takes the initiative and charges directly at the Demon King but is effortlessly deflected before he attacks Meliodas and Ban, claiming he won't let any of them return to the living world.

Due to Meliodas not having his body, Ban is forced to carry him out of trouble and attempts to steal the Demon King's strength using Physical Hunt but instead ends up having his strength stolen for some reason, making them both easy prey for their opponent and despite their continous attacks and Wild's own techniques, the Demon King easily overpowers them all, annoyed by their continous persistance and reminds them that he is the only one who allows anyone to escape from Purgatory, despite Meliodas' claim that he doesn't get to decide that.

He then summons a lightning storm at them and Meliodas sends it back with Full Counter (to Wild's surprise) but the Demon King merely absorbs the magic energy instead and Meliodas reveals his father's power to be "The Ruler" which makes him immune to all magic powers. The Demon King himself becomes bored with their resistance and claims they can continue to struggle in vain or simply vanish from sight; yet he asks Meliodas about why he can't remember anything about Estarossa and says he too shares this problem as he remembers the other Commandments vividly despite being struck within Purgatory for over a billion years yet remembers nothing about Estarossa and realizes the one responsible is none other than the original Gowther.

Aftermath
Ban and Meliodas decide to tell Hawk about his brother when they see him again.