Old Maou Faction

The Old Maou Faction (旧魔王派 KyūmaŌ-ha) was the largest faction of the Chaos Insurgency, comprised of pure blooded Demons that fanatically supported the world domination ideals of the original Satans, Lucifer, Beelzebub, Leviathan, Asmodeus, Mammon, Belial, and Belphegor, had allied themselves with their descendants.

Summary
The Old Maou Faction was indirectly formed when a group of Demons decided to continue the Great Mythology War in order to fufill the Original Satans's ambition of world domination, while another group of Demons and Imps were against it, resulting in a Civil War among Demons, with the victor being the new Government of the Demon and Imp side of Hell, while the losers where forced to go into hiding and the original Seven Great Satans became known as the Old Satans.

Even after being defeated by the new Demon government, the Old Maou Faction remained active and continued to cause trouble on the Demon side.

The Old Maou Faction was the only group of Demons who resisted using the Master-Servant Contract and Evil Pieces, as they believe them to be a disgrace to Demons because they reincarnate Humans and other races into Demons. They were also against the Demons' current political system of peace and pacifism and seeked to change it by overthrowing the current Satans as their ultimate goal was to destroy the current world by creating and spreading chaos and recreating it into a world under the dictatorial rule of the descendants of the original Satans.

Sometimes prior to the main story, the Old Maou Faction pledged allegiance to Satanael and Wagyl in order to borrow Wagyl's snakes and Satanael's father, Marius' power, for the sake of world domination, thus, becoming the largest faction amongst the many factions of the Chaos Insurgency. They eventually reemerged as part of Chaos Insurgency, as one of its leaders, Tsufaame Leviathan, led the attack at the peace conference of the Five Factions, attempting to kill the leaders of the Five Factions in order to spread chaos throughout the Factions as a beginning to realize their plans for world domination, but was killed by the combined of Azazel and Galahad.

The Old Maou Faction eventually launched another large-scale attack on Hell with the help of Dioddora Astaroth. However, like their previous attempt, it was thwarted by the leaders of the Five Factions along with the allied forces from other myths, resulting in the loss of another of their leaders, Olba Beelzebub and Creuserey Asmodeus, while another, Zachan Mammon, was heavily injured.

Following the failed attempt during the Rating Game tournament, the Old Maou Faction formed a truce with the Hero Faction and New Olympus Faction. After the Hero Faction betrayed Wagyl and Satanael, Zachan, who had gone insane by then, forced Alice into a Overdrive state in an attempt to destroy Hell by generating powerful anti-monsters. He was then killed by Arthur and Glaceon.

The remaining top members of the Old Maou Faction, Charlemagne of the Hero Faction, and the last surviving leader of the Old Maou Faction, Zolgear Belphegor then approached Myrddin Beelzebub during the crisis of Hell, offering him a place in the Chaos Insurgency, while other members participated in riots in Hell, taking advantage of the chaos. However their offer was rejected by Myrddin and they were swiftly terminated, with a great deal of their members being defeated. With the third defeat, the Old Maou Faction lost the majority of its forces and was forced into hiding, unable to take any further action being disbanded as a result.

Members
All the sub-leaders of the Old Maou Faction were killed and the majority of its forces were terminated by Myrddin Beelzebub in Volume 12, further weakening their faction to the point of them being incapable of taking any further actions.