Demon Clan

The Demon Clan is one of the most powerful races in the Multiverse, and resides in the Demon Realm, where they are currently in peace with the Goddess Clan under their king, Meliodas.

Overview
Three thousand years ago, the Demon Clan constantly clashed with the Goddess Clan. Their elite group of warriors are the Ten Commandments, who were handpicked by the Demon King due to their power. Many demons consider themselves above those of other races for their great power, especially humans. However, the two legendary clans were largely evenly matched and thus a tentative balance was created. At some point in time, the Goddess Clan broke a treaty with them, and even slaughtered many women and children they were holding as prisoners of war.

At some point, the Vampires became allies yet subservients to the Demon Clan. When the leader of the Commandments, Meliodas, betrayed his own people for his alliance and relationship with the powerful goddess, Elizabeth, and severely crippled their strength by killing two members of the Ten Commandments when escaping, it indirectly caused two events: The rest of the ​​​​goddesses seized the opportunity to defeat the Demon Clan, who waged a great war against the Goddess Clan, who had allied with the Giant Clan, Fairy Clan and humans. The Vampire Clan decided to rebel during this time as the Demon Clan got weaker, but still got single-handedly defeated.

As a result, the Demon Clan was ultimately defeated by the Goddess Clan and their allied clans, being sealed away in the Coffin of Eternal Darkness for many years. In spite of their fate though, a few demons managed to escape from or avoid the seal completely, namely the Red Demon, Gray Demon and Fraudrin. The latter would spend sixteen years trying to find a way to break the seal and to resurrect his clan, so they could take over the land of Britannia. The other nine members of the Commandments were eventually resurrected when Hendrickson manages to break the seal in present day. Their biggest threat on their way to conquer the country once more turns out to be a member of their own race; Meliodas, their previous leader and the oldest son and heir of the Demon King, who was still alive thanks to his father's Immortality Curse.​ After organizing a fighting festival to lure Meliodas into a trap, they managed to kill him and begin the conquest of Britannia in the following month, taking the soul of every human they come across in order to regain their strength. However, when the Ten Commandments try to conquer the kingdom of Liones, they are eventually stopped by the group formed with the goal of destroying them, the Seven Deadly Sins, as well as Meliodas, who has revived thanks to the curse that the Demon King put on him.

The remaining members of the Ten Commandments, Zeldris and Estarossa, took refuge in their established base in the kingdom of Camelot, where they sacrificed human souls in order to completely break the seal and liberate the entire Demon Clan. Eventually, the fearsome Cusack] and [[Chandler joins them, as did Meliodas, who had decided to become the new Demon King to break the curse on him and Elizabeth. When the Four Archangels of the Goddess Clan revive to join Elizabeth, the Seven Deadly Sins and the humans against them, the Demon Clan faces a new Holy War.

Appearance
There is no set appearance for members of the Demon Clan - some are monstrous in appearance, such as the Red Demons, Gray Demons, and other members such as Fraudrin and Dahaaka.

Other demons resemble other creatures, like Dorocchio, who is essentially a walking and talking lion, and Melascula, whose true form is that of a giant serpent.

Many high-ranked demons, including the majority of the Ten Commandments are humanoid in appearance - the only tell-tale sign that they are of the Demon Clan are their pitch-black eyes, and, in some cases, the black Demon marks on their bodies and their Darkness. Examples of Demons with this appearance include Meliodas, Zeldris, Gowther, Bellion and Derieri.

There are also other members of the Demon Clan who were originally of other races, namely Drole, who was formerly of the Giant Clan, Gloxinia, who was formerly of the Fairy Clan and Estarossa, who was in fact one of the Four Archangels, Mael. In the case of the former two, they retained their appearance from their original species, plus the pitch-black eyes and Demon marks, whilst Estarossa lost features of the Goddess Clan, including his wings, taking on the appearance of a natural-born demon.