The Demon King is shadowed in his first appearance, towering over Meliodas. In his first full appearance he is seen as an enormous armor-clad man whose height reaches the clouds. He wears a long partially torn cape and wields a massive sword. He also has horns and a full long curly beard.
Not much of his personality is known yet. He seems to put power and evil above all else, chastising Meliodas for throwing away his former life just for the sake of one woman. He also has no empathy for those who go against the laws of the Demon Clan.
3,000 years agoEdit
During the last few days of the Ancient War, he and the Supreme Deity having lost their patience in their shared anger and having had enough of their children's repeated defiance of the laws of their clan worked together and fought against Meliodas and Elizabeth, effortlessly killing them and cursing them for eternity. The Demon King cursed Meliodas with immortality as his punishment.
After Meliodas's fight with the Ten Commandments, the Demon King greets him in Purgatory. He admits to having been keeping an eye on the captain of the Seven Deadly Sins throughout and muses that even Meliodas was unable to do anything other than wait for death when caught by the Commandments of Piety and Love. When Meliodas counters that he is now free from the Commandments' bindings thanks to his curse, the Demon King agrees but mentions that he can feel Meliodas' quivering. Entertaining Meliodas' bluffs, he expresses anger towards the certain woman who had changed Meliodas and then informs him that though he was left in a greatly weakened state, the curse he casted on the Dragon's Sin of Wrath would allow him to feed on his emotions every time he dies, allowing the Demon King to regain his lost power and at the same time reverting his traitorous son back to the state he was three thousand years ago. He is then attacked by an outraged Meliodas.
Abilities and EquipmentEdit
As the ruler of the Demon Clan, he is the most powerful demon. The Demon King is extremely skilled with blessings and curses, having been the one who created the Commandments that the Ten Commandments wield. He is also responsible for the curse on Meliodas that has lasted for at least three thousand years that can only be broken with a power equivalent of his or the Supreme Deity.
He is strong enough to easily kill Meliodas in the Ancient War. All three of his sons inherited his strength, with their individual power levels amongst the highest of all known characters.
- Commandment「戒禁 Kaigon」: The Demon King is capable of bestowing a Commandment on those he deems suitable. These Commandments deliver a unique curse to whomever breaks a rule specific to each Commandment. This power is absolute; it cannot be opposed even by its wielder. The curses will only be lifted if the victim defeats its wielder or at the victim's death. Notably, these curses are not magical in origin, activating even when their holders are drained of magic, and are perceived differently than magic is as well.
信仰Shinkō」: Those who show faithlessness in the holder's presence will have their eyes set ablaze. It was held by Melascula.
慈 愛Jiai」: Those who stand before the Commandment holder with hatred in their hearts will be rendered powerless to harm or inflict damage on anyone else. It is held by Estarossa.
不殺Fusatsu」: Any who kills in the holder's presence will have their own time stolen from them, causing the victim to age rapidly and die. It is held by Grayroad.
忍耐Nintai」: The curse and its activation are unknown. It is held by Drole.
敬 神Keishin」: Any who turn their back to the Commandment's holder are treated as committing an act of treachery, and are cursed into serving the Demon King, and by extension the holder who is acting as the Demon King's representative. It was once held by Calmadios, and is currently held by Zeldris.
純 潔Junketsu」: The curse and its activation are unknown. It is held by Derieri.
安息Ansoku」: The curse and its activation are unknown. It is held by Gloxinia.
沈黙Chinmoku」: The curse and its activation are unknown. It is held by Monspeet.
無欲Muyoku」: Those harboring greed, avarice and desire will be inflicted by its curse will lose their memories, feelings, and entire sense of self. It was once held by Gowther, but was later passed on to Fraudrin upon Gowther's disappearance.
真実Shinjitsu」: This Commandment determines that any who tell a lie in the holder's presence will be turned to stone.  However, only those who are aware that they are lying will be affected. It is held by Galand.
- Immortality Curse: This curse revives the victim without fail regardless of the means of death, including suicide or getting killed, no matter how many times they die. It additionally prevents the victim from dying of old age. In exchange for the infinite number of revivals, the victim's emotions are slowly drained to nourish the King. The conditions to dispel it are to get a power equivalent to the King himself or the Supreme Deity. The only known victim of the curse is Meliodas.
He and Meliodas now have an antagonistic relationship, though how it was before Meliodas betrayed the Demon Clan is unknown. He lightly mocks his defeat and descent to Purgatory, yet he seems to revel at the idea of bringing his traitorous son back into the fold, with force, if necessary.