It is unknown how long Neron has been a power in Hell, nor just how much power he wields there. It is said his name was the numerological source for 666, the "number of the Beast." Neron's greatest strength and joy is his ability to know exactly what someone wants the most. He cannot resist a deal, and it is this which first brought him to the attention of Earth's superhero community.
Setting himself the goal of corrupting the most pure soul of any super-being, Neron began his plan by approaching five high-caliber villains to act as his "lieutenants:" Abra Kadabra, Lex Luthor, Circe, Polaris, and the Joker. He then sent Kadabra to contact five members of the Flash's Rogues' Gallery: Captain Boomerang, Captain Cold, Heat Wave, Mirror Master, and Weather Wizard. Promising a chance to be remembered "as the most infamous villains of their age," Neron sent them on an errand of destruction that claimed their lives as they set in motion a plan in which Neron obtained the souls of many villains—and heroes as well—before he was ultimately defeated by the Trickster, who had somehow managed not to owe Neron a thing.
Later, in a plot to steal Wally West and Linda Park's love, thereby removing the Flash's anchor to reality and opening a door to excessive power, Neron sent the five Rogues back to Earth without their souls, making them ruthless killers—the only way the Flash could defeat them to bargain for their souls with what he had himself. Fortunately for Wally, Linda, and the world, their love corrupted Neron, turning him "nice," and he was forced to return it.
Neron has since battled various heroes, stormed Heaven, killed Wonder Woman, and continues to seek revenge on the Trickster. An attempt to manipulate events so that he could simply reach out and take souls, rather than dealing for them, caused him to be stripped of his status, demoted to a rhyming demon. At present, Neron is trapped in Dr. Fate's tower, tricked there and bound by Ralph Dibny.
Neron makes his live action debut in the CW TV series DC's Legends of Tomorrow, and appears as the main antagonist in Season 4. He is a mysterious and powerful demon who is pursuing John Constantine and has an interest in the magical "fugitives".on. At present, Neron is trapped in Dr. Fate's tower, tricked there and bound by Ralph Dibny.
Neron offered great things to the heroes and villains of DC such as new powers, the chance to see deceased loved ones again, usually in exchange for their souls, some accepted his offer, others rejected it.
Heroes Who Accepted
Blue Devil: Made a deal for fame and fortune in exchange for destroying an unmanned power station, indirectly causing the death of his agent Marla Bloomberg.
Guy Gardner: Offered the resurrection of his loved ones and the return of Coast in exchange for killing John Stewart. He agreed because Neron lied to him, telling him Stewart should already be dead but a rift in time had prevented it, and this had caused Guy's tragic history to occur. Guy then changed his mind.
Harlequin: Had her youth restored, but her soul was won back and the deal undone by the original Green Lantern Alan Scott.
Hawkman: One of his "Hawk-Avatar" spirits sold its soul to gain ascendance over the other avatars also resident in his body, but failed.
Madame Xanadu: Offered power over demons in exchange for her soul on her death, which she accepted - to trick Neron because she was immortal. Neron offered a deal just to prove that he could tempt those with 'gray souls' as well as those who were evil.
The Ray: Thought Neron was a beautiful woman, Kathy Noren, who worked in his office. Neron makes a deal with Vandal Savage not to go after Ray's soul in exchange for Vandal guiding Neron to Atomic Skull instead. Ray then approaches Kathy/Neron,who avoids the conditions of the deal with Vandal Savage by letting Ray make the offer to take flowers to a hospital in exchange for Death Masque no longer having existed - and thus Ray's father would not die. Did not fulfill the terms of his deal.
The Spectre: The essence of The Spectre (not his host, Jim Corrigan) agreed not to oppose Neron in order to be free of Corrigan. The deal did not include not fighting other demons, so Spectre became involved in the supernatural heroes attack on Hell.
Vril Drox II: Sold somebody's soul for information on how to regain control of L.E.G.I.O.N. by killing his son Lyrl Dox. Also had Iceman killed (actually he asked for him to no longer be a problem, but was happy with the result).
Heroes Who Rejected
Batman: Offered the resurrection of the Jason Todd.
Captain Atom: Unknown offer.
Flash (Wally West): Offered the resurrection of Barry Allen.
Green Lantern (Kyle Reiner): The resurrection of Alex DeWitt.
Knockout: Offered "power, prestige, anything you could dream of".
Mystek: Unknown offer.
Oracle: Offered the use of her legs again, invulnerability and powers to rival Superman's if she would become his librarian, while her soul was hers to keep. She declined, fearing she would lose her soul anyway.
Silver Swan: Unknown offer.
Superboy: offered the chance to become Superman.
Triumph: Was offered his lost 10 years back, and thus the opportunity to become a major hero and lead the Justice League America if he opened a box containing one of Neron's candles.
Villains Who Accepted
Abra Kadabra: Neron's Lieutenant, was given real magic powers instead of his technological based magical powers and become part of Neron's Inner Council. It is not said whether he sold his soul.
Atomic Skull: Offered greater power and the life of his love, Zelda.
Azrael: One of the Azrael characters who fell to his death after battling the real Azrael,was offered his life. As a result he was saved during his death fall, given the Azrael/Batman costume and offered the chance to kill Batman, to distract Batman from Neron's plans.
Blackguard: Offered enhanced intelligence, strength, and equipment.
Black Manta: Gains a manta-like body with superhuman powers.
Blaze: Initially became one of Neron's Lieutenants and assigned to keep the DC Universe's mystical heroes occupied. Sold to Neron by her demon brother Satanus in return for his own soul back.
Blockbuster: Asked to be smarter, but later realized he should have asked for more.
Brimstone: Techno-seed and the Brimstone personality possess a S.T.A.R. Labs scientist who deals with Neron for power; he was killed.
Captain Boomerang: He was given healed, cybernetic hands and the promise he would be one of the greatest villains ever. Killed carrying out his task.
Captain Cold: Promised he would be one of the greatest villains ever. Killed carrying out his task.
Cheetah: Initially it seemed that the Cheetah had been given a more bestial form, and becomes more animal as she gets angrier; later, it was explained that she had sold her soul to resurrect a friend, resulting in the aforementioned reversion to a more feral state.
Chiller: Given a chance to carry out his dream assassination...the murder of a well-protected pop star.
Chronos: In exchange for attempting to kill Atom, he was given time-travel, time manipulation, and phasing powers, but these caused accelerated aging. He then devised a glove that allowed him to age others instead, thus partly negating the deal.
Circe: She was given greater power to avenge her defeats by Wonder Woman; became part of Neron's Inner Council.
Copperhead: He became a snake-man hybrid, with enhanced reflexes and agility, venomous fangs, a forked tongue, venomous claws, and a prehensile tail; but now susceptible to cold.
Deadline: He was given the chance to carry out his dream assassination...the murder of a Texas District Attorney.
Deadshot: He was given the chance to carry out his dream assassination,...the destruction of an entire kindergarten.
Doctor Polaris: Sold his soul to be rid of his benevolent personality, Neal Emerson. Became part of Neron's Inner Circle.
Enforcer: He was given enhanced equipment, superhuman strength, durability, and flight powers.
Evil Star: He becomes able to create dozens of his "Starling" spawn, though they are no longer indestructible as were the original five "Starlings".
Gorilla Grodd: He gained restored intelligence and psionic powers. Told the whereabouts of The Talisman of Arok to legitimize his reign over Gorilla City, but Catwoman keeps it from him.
Heat Wave: He was promised he would be one of the greatest villains ever. Killed carrying out his task.
Hellgrammite: He was given enhanced powers, and his "Drone" offspring can no longer be converted back to human by exposure to x-rays.
The Joker: He sold his soul for a box of Cuban cigars. Became part of Neron's Inner Council, but double-crossed him.
Lex Luthor: He was restored completely to health after his cloned body fell victim to a clone plague' in exchange for his soul and giving 'consultancy' to Neron. Became one of Neron's Inner Council but double-crossed him.
Lobo: He has Neron rid him of a radio that had been implanted in his brain for 20 years by wishing it to Neron after Neron refused to grant the first deal - Neron's own soul - as he didn't have one.
Major Disaster: He was given the magical ability to perceive probability and locate weak points in objects and people in exchange for killing Aquaman. Mistakenly kills Thanatos, who has usurped Aquaman's place in Atlantis, instead.
Merlyn: He was given the chance to carry out his dream assassination... the murder of Batman.
Metallo: He gained the ability to morph into any mechanical shape he could imagine and project his consciousness into any technological or metallic device, as well as absorbing any machinery he came in contact with to enhance his body.
Mirror Master: He was promised he would be one of the greatest villains ever. Died carrying out his task.
Mr. Freeze: He was given natural cryokinetic powers.
Ocean Master: He was given a staff that granted him magical powers, but it caused him excruciating pain when he was not actually holding it.
Ragdoll: Youth restored and flexibility enhanced by Neron in exchange for destroying Opal City and harming the Shade. Satanus - He became a Lieutenant of Neron and was assigned to kill the Leymen of Primal Force publicly. When he failed, he traded information on the whereabouts of his sister for his soul back, but was killed after threatening Neron when it was returned.
Shadow Thief: He was given a more powerful costume possessing the ability to bring shadows to life and change other people and objects to evil shadows under his control.