In the depths of the DC Universe are some great though largely unknown cosmic entities. Not relying on the space-wandering Kyle Rayner and his Guardians to run into him, let’s take a gander ourselves at … Nebiros!
Nebiros first appeared in Swamp Thing #15 (January 1975), and was created by David Michelinie and Nestor Redondo.
Nebiros is a ten thousand-year-old demon god who escaped from Hell through sacrificial offerings. The Nebiros empire grew and threatened other great powers of the day like Lemuria, Mu and Atlantis. The great sorcerers of Earth banded together to destroy Nebiros, and banished him to a dark dimension.
Six thousand years later, Nebiros possesses the body of Swamp Thing with the aid of deluded priest Jonathan Bliss. When Abigail Arcane and Matthew Cable destroy its globe vessel, the spirit is exorcised from the Swamp Thing's body and takes over the priest's body, which withers under the power of the spirit, sending it back to the netherworld.
Nebiros is freed again years later by Dan Cassidy and is defeated in Mexico by Cassidy's own demonic alter-ego Blue Devil and the magician Zatanna. Nebiros is again forced to return to his own Dark Realm.
Nebiros later appears in Books of Magic (the monthly series) and in the limited series Day Of Judgement. There he is the last demon to remain in Hell. The combined efforts of Etrigan the Demon and Asmodel had caused the Spectre to merge with the fallen angel.
As one of the side effects, the fires of Hell had gone out, Hell had frozen over and all the demons had invaded Earth. All except Nebiros. He stays behind in the City of Dis, armed with what he claims to be the trident of the King of Lies himself. A small team of heroes ventures into Dis in order to restart the fires. Sebastian Faust is part of the team. Faust has gained powers from Nebiros himself in a deal gone wrong, powers intended for his father.
Faust, using bones bought in Paris, recreates the demonic Blue Devil. In short order, Blue Devil steals Nebiros' trident and kicks the demon high into the air. A blast from Firestorm turns the water in the demon's body into cement, seemingly killing him.
Readers would like to see more of Nebiros in the New 52, I think.