Demons (Nanatsu no Taizai)

The Demons (or Demon Clan) is a race of generally humanoid beings that live in another dimension known as Purgatory. An evil race that wanted to subdue humanity and all the other races on Earth, however, they fail after being sealed by the Goddesses.

History
Thousands of years ago, the Chaos entity gave life to three beings the Demon King, the Supreme Divinity and the Sacred Tree, three beings equivalent in magnitude and strength, the Supreme Divinity created a race called Goddesses, where she would be the ruler while the Demon King created the demon race, which he would be the ruler of.

3,000 years before the recent events, the goddesses went to war against the demons, in that war it was created a group handpicked by the feared Demon King, the Ten Commandments, the King divided a part of his power in 10 parts and gave for each of them. At some point in this war, the vampires became subservient allies of the demons, but the demons lost one day, it was the fault of a traitorous demon, who left his people claiming that the motive was love for a goddess named Elizabeth, the legitimate daughter of Divinity Supreme, this demon was Meliodas, leader of the Ten Commandments, and son who would inherit the Demon King's throne, he then tried to escape with Elizabeth away, defeating most demonic armies. That was when the goddesses managed to seal the demons by joining the race of giants, fairies and humans. They were sealed in the Coffin of Eternal Darkness, where they would stay for another 3,000 years, however, three demons had managed to escape their prison, a Red Demon, a Gray Demon and Fraudrin a member of the Ten Commandments.

Nowadays, the human Hendrickson controlled by Fraudrin managed to break the seal, releasing the Ten Commandments, now the only one who could stop them would be Meliodas, who even after 3,000 years (a demon with a normal life would never pass that age) I live thanks to the curse that the Supreme Divinity has given you. Creating a “Battle festival”, they lured Meliodas into a trap and Estarossa, his younger foster brother killed him and with Meliodas out of it, they could restart their plan to dominate Britannia, only to have to retreat as they had to face The Seven Deadly Sins, the group formed to stop them together with Meliodas resurrected by the curse of Divinity. The remaining members of the Ten Commandments, Zeldris and Estarossa, Meliodas' two brothers, fled and hid in Camelot, and sacrificed human souls to finally break the seal and release all the demons at once, after a while Cusack and Chandler join Zeldris, Estarossa and Meliodas, who is there to become the new Demon King only to break the curse imposed on him and Elizabeth.

The Four Archangels revive and join Elizabeth, the Seven Deadly Sins and humans in a new Holy War against demons, during the struggle of Zeldris, Chandler, Estarossa and Cusack against the Seven Sins, it is revealed that Meliodas' younger brother, Estarossa is actually an angel whose memories were altered by the demon Gowther.

Finally with the defeat of the Demon King, the Holy War ends, however, he manages to revive and possesses the body of Zeldris to conquer Britannia and become the god of that place, after several events, Meliodas manages to convince Zeldris to fight against his father, making him being expelled from Zeldris's body. In a last-ditch effort to destroy his traitorous children, Elizabeth and sins, he uses his last strength to possess Britannia herself, however, he is driven out by Meliodas who, along with other sins, destroys all the Demon King's commandments, ending him once and for all and saving everyone from the demons.

Biology
The demons are beings externally practically equal to humans, but inside there are several differences, some demons have seven hearts, and can only be killed if all of these are destroyed, because demons have a monstrous resistance as well as a very accelerated regenerative fact, which can put one arm in place in seconds. Demons also have interesting racial abilities, including the power to control darkness, they can manipulate dark energy for a variety of purposes, such as turning them into blades to attack, creating an extension of their arms to capture or defend, making pieces of clothing, creating wings to fly, among others... They also have a skill known as Hellblaze, they can create black and purple flames and manipulate them at will to defend or attack, these blades also negen regeneration. Devouring souls is also in a demon's arsenal, when they want to absorb a soul they can open their mouths, and the being that he wants to devour the soul in his field of vision will have the soul absorbed and it will be drawn into the mouth of the devil. Demons who have seven hearts and pass the power level of 50,000 have access to Indura Transformation, a transformation that spreads some black spots over your body, your physique is more defined and some transformation occurs in some part of your body, like Derieri, who when he activated Indura Transformation, he developed a crab claw in his right hand. The blood of demons also has special properties, if a being with the same blood type as the demon drinks his blood, obtains the powers of the demon who thirsted for blood, a being can drink as many types of blood as he wants as long as it is compatible, if not that is, the body will begin to inflate until it explodes.

Appearance
In general, the demons have a humanoid appearance, if not completely human, the completely human demons on the outside are usually white skin and black eyes, with different hair colors. Those who are not completely the same look very different from each other, some examples are Atollah, which has a half white, half red glass, with the red side apparently falling, Baruja, which is a quadruped being with spines on its back, Derocchio, humanoid lion, among others… However, there are demons that are the same, like the demons called Albion, which has a gray color similar to statues, covered with mosses with “x” eyes, the red demons, which are extremely cobble and giant, with purple lips and big tongues, orange demons that look like fat humanoid bears, among others...