Demon King

The Demon King (魔神王, Majin-Ō) is the supreme ruler of the Demon Clan and the overarching antagonist in The Seven Deadly Sins anime (particularly prominent in the later seasons, including the Demon King arc and the final battles).

He is the father of Meliodas and Zeldris, viewing them primarily as tools or heirs to his power rather than with any genuine affection. He cursed Elizabeth with perpetual reincarnation and death (in collaboration with the Supreme Deity's curse on Meliodas) as punishment for his son's betrayal and to make him suffer eternally.

In terms of appearance in the anime, his primary form is that of a massive, imposing figure far larger than even giants — a robust, balding man with a long, curly white beard, clad in heavy greyish armor, a torn cape, and a horned helmet that shadows his eyes, bearing the Demon Clan symbol. He exudes an overwhelming, tyrannical presence. (He later takes on different forms through possession, such as a more youthful, muscular version with long black hair and goatee when fully inhabiting Zeldris's body.)

His personality is ruthless, tyrannical, and coldly authoritarian. He is fanatically devoted to the Demon Clan's supremacy and dominance, despising betrayal (even from his own sons), weakness, or "effeminate" emotions like love. He shows no mercy, punishes disloyalty with extreme cruelty, and prioritizes absolute control and power above all else.

As for his powers, he possesses god-like strength among demons — including "The Ruler" (which reverses or nullifies incoming attacks/magic directed at him), immense physical power, high-level summoning, darkness manipulation, curses (like those on Meliodas and Elizabeth), and the ability to grant Commandments (powerful cursed abilities) to the Ten Commandments. His sheer presence and magic are so immense that his full power risks destroying the world of Britannia if unleashed unchecked, which is why he remains tied to Purgatory for much of the story until possessing vessels.