Demon King

Personality
The Demon King appears to value power and evil above all else,chatisising Meliodas for abandoning the Demons for Elizabeth. He has no empathy for Demons who go against his laws,even his own children.

The Demon King is not above mocking and being ruthlessly sarcastic and openly hostile to those he dislikes despite apparently being very focused in his goals to have the Demon Clan conquer Brittania,evidenced when he took his time mocking Meliodas's defeat and descent to Purgatory and evidently relished and took pleasure in outmatching and angering Meliodas in their talk.

However,the Demon King is not completely without mercy and forgiveness,at least with his sons,as while hostile,he evidently was willing to consider returning Meliodas back. He also was completely disregarding of Meliodas's betrayal when he returned and send Zeldris to retrieve him.

Abillities and Equipment
The Demon King is terrifyingly powerful,being the ruler of the Demon Clan,the most powerful race in Brittania aside from the Goddess Clan. He is the most powerful demon,evidenced by his abillity to effortlessly kill Meliodas in the Holy War. Zeldris has said that even his borrowed power doesn't compare to the King's own power and only with the 10 Commandments can Meliodas be as powerful as the Demon King.

The Demon King is exceptionally skillfull with blessings and curses,having been able to create the unique Commandments that the 10 Commandments wield by splitting his power and being able to cast the nearly unbreakable curse on Meliodas that can only be lifted by a force as powerful as the King is.