Naga Clan

The Naga Clan are a clan of extra devils who have been active since ancient times. A isolated clan who at some point were at rival with the Adramelech Clan in a attempt to steal their large assortment of treasure. Because of their unnatural talent for stealth and stealing and their former relationship with Hades, they are generally not trusted by other devils and as a result live as a very isolated lives, generally only working as spies or assassins. After the minor collapse of the Old-Satan Faction, this clan numbers have grown exponentially due to dozens of old Satan faction devils, not wanting to accept the New Satan Faction rules joining the Naga Clan. Members of this clan are generally noted for the snake scales either on their necks or hands.

Summary
The Naga Clan were once a clan used by Hades in his attempt to "tame" devils, by using a powerful curse on the Naga Clan, they were gifted with the power to turn into snake or human at will and as a result were used by Hades as his spies. The Naga Clan however betrayed him and after making off with a bunch of his treasures returned to the Underworld, causing them to add to Hades resentment towards devils. The Naga Clan however never allied with either faction during the Great War or during the Devil Civil War and instead were content to steal or work for whoever had what they wanted and as a result they were generally despised or hated by all sides, with even members of the Naga clan stating this is the reason they don't live very long. However because the Naga clan is willing to take on any devil, even devils from other factions, especially traitors and criminals, is the reason they continue to grow despite their general short lives among devils.

After the conclusion of the Devil Civil War, they generally tend to not mess with the New Satan Faction out of fear of Nicholas Satan destroying them but continue to cause trouble as thieves, generally stealing from anyone they come across. They also generally live isolated lives, typically taking residence in cities made up of the materials they stolen from Hades.

Trivia

 * While the Adramelech Clan were based off birds, the Naga clan were based off snakes, hence their name. This rivalry also forms the snake vs. birds trope and the Naga trying to steal their treasures is a reference to snakes generally stealing bird's eggs.
 * Their clan head's name is also a reference to King Cobra.
 * Their name can also be a reference to Nagisa from Assasination Classroom, who is often depicted as a snake-like assassin.