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 a woman. He is also not above mocking and being ruthlessly sarcastic to the ones he dislikes. He has no empathy for those who go against the laws of the Demon Clan, even if it is his own son. However, the Demon King is not completely unforgiving and without mercy, at least when it came to Meliodas, his first, strongest and seemingly favored child, as while he was hostile towards his traitorous son when he was in Purgatoy, The Demon King was fully willing to crown Meliodas as the New Demon King when he had returned to his old self. Cusack even said The Demon king was being far too compassionate with Meliodas and even noted he did this because he still consideres Meliodas as his son despite their currently mutually antagonistic relationship. It is also noted that The Demon King is extremely unpredictable, even to his sons, as Zeldris, who is his representative, noted he can never know what his father is thinking.
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.
Current arc Edit
After Meliodas fight with Escanor, the Demon King senses that his son has starting to return to his former self, much to his delight. He contacts his youngest son and representative, Zeldris, and shows no interest when Zeldris expresses he will find the one who killed the demons guarding Camelot, instead telling Zeldris that while his seal is not yet broken, Meliodas will now replace him as the rightful heir to the throne of the demon king. Despite Zeldris obvious shock and visible anger and discontent, the Demon King casually orders Zeldris to retrieve Meliodas and crown him as the new demon king.
Abilities and EquipmentEdit
As the ruler of the Demon Clan, he is extraordinarily powerful and strong, as he is certainly the most powerful and strongest demon alive as he was able to easily kill Meliodas in the Ancient War.
The Demon King is also exceptionally skillfull with curses and blessings, having been the one that created the Commandments that the 10 Commandments wield. He is also the one responsible for the curse on Meliodas that can only be lifted by the King himself and the Supreme Deity, or someone as powerful as both gods.
- 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 is 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 is curse that 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 condition to dispel it is to get a power equivalent to the King himself or the Supreme Deity and aside from the Demon King and the Supreme Deity themselves, only Zeldris, the one who has been lent the demon king power, is known to hold the power to be capable of such feat. The only known victim of the curse is Meliodas.
He and Meliodas now have an extremely antagonistic relationship. Though how it was before Meliodas betrayed the Demon Clan is unknown, except he is seemingly favored above his younger brothers as he was considered to be the most worthy heir to the throne, but currently Meliodas holds nothing but hatred and anger for his father due to him being the one who cursed Meliodas with immortality which thanks to the Supreme Deity curse, effectively keeps him apart from Elizabeth. The Demon King also holds visible anger and resentment for his son betraying him as evidenced when he lightly mocks his defeat and descent to Purgatory and also showed visible mockery at the sin of wrath. However, it appears the Demon King still considers Meliodas to be his son and the rightful heir to his mantle and throne, as evidenced when he openly revels in the idea of bringing his oldest son back to the fold and after Meliodas fell back into his former self, the Demon King was delighted and immediately ordered Zeldris to retrieve his elder son and crown him the new king of the demons, apparently disregarding his son's betrayal despite Zeldris' visible discontent and shock.
He and Zeldris have a fairly good relationship. The Demon King gave Zeldris his power to use and Zeldris appears to respect his father greatly, immediately apologizing for having The Demon Clan embarassed at his command and promising to find and kill the one who humiliated them. The Demon king is also not afraid to be firm to Zeldris, as he was able to silence his youngest son quite casually when he questioned his order to rescue Meliodas, and it appears Zeldris is fully loyal to his father, as he, albeit very begrudgingly, obeyed when The Demon King ordered him to crown Meliodas as the next King of Demons.
Memories of the Holy War arcEdit
- Meliodas and Elizabeth vs. Demon King and Supreme Deity: Win