The Dheronians are a nocturnal humanoid species, having bleached hair and skin due to evolving on the near un-sunlit environment of their home planet. Their physiology and powers are similar to their Kryptonian counterparts, only except that their powers metabolize without light; a complete opposite to the Kryptonians's dependency on solar energy, which happens to be fatal for the Dheronians if they are completely exposed to sunlight. Because of their nocturnal physiology, Dheronians are very sensitive to bright lights.
The Dheronian race evolved on the planet Dheron, the seventh planet in the Ku'Raon System and lie at the very edges of the system; originally in the past, Dheron's orbit had been closer until it was changed due to a meteor-impact. Because of the planet's location, its environment was harsh that it's quite similar to the harsh conditions of ancient Krypton, with few resources beyond the basic essentials. However, life miraculously persevered which gave birth to the Dheronians.
History for the Dheronians began as simple farmers and eked out an existence of survival by trying to cultivate what little they could on their less abundant planet. Their life changed once their planet came within orbit of Krypton during the Age of Wars and attracted the attentions of Jax-Ur, who discovered Dheron was enriched with Raonite ore that was used in creating Nova Javelins, and then quickly established trade with Dheron, giving its people resources and technology in exchange for all the Raonite he needed. Immediately thereafter, Dheron went from an agrarian society to an industrialized civilization overnight. This trade went on for most of the duration of the Age of Wars. When the Age of Wars finally ended with Jax-Ur's defeat and banishment, Dheron's trade came to a complete stop that severely almost collapse the Dheronians' economy and its resources all but taxed beyond recovery. With their society on the verge of collapse, the Dheronians blamed their troubles on the Kryptonians at their apparent "abandonment" and began attacking Krypton every chance they have left by trying to raid their world for what they lacked.
The conflict was fairly matched as the Dheronians's technology are Kryptonian-based. As Krypton's scientific revolution went on, the Dheronians' raids became more and more of a nuisance. After several centuries, the Kryptonians invited a delegation from Dheron to take part in a peace-treaty in another attempt to end the feud. However, as the Dheronian delegates delayed the treaty, a Dheronian infiltration team broke into some of the Kryptonian laboratories and shipyards, trying to steal more technology, but was discovered and foiled by the Sapphire Guards. This incident became finally intolerable for the Kryptonians; after the Dheronian delegation was deported back to their planet, the Kryptonian Defence Force launched a missile, containing an energy-drill, at their world and bored into its crust, anchoring it and pushing Dheron out of the Ku'Raon System, and thereby banishing the Dheronians into deep space.
Without any warmth from Rao, Dheron became colder and unable to sustaining life that drove the Dheronians to abandoning their planet; but not without significant costs as only a sizable majority of the Dheronians were forced to be left behind in exchange for the survivors to escape on the available arkships with the meager supplies they possessed. The survivors were reduced to scavengers, finding whatever to sustain them and only landing on the darkened parts of planets that their bodies were unable to tolerate sunlight. Their plight forever cemented their resentment for the Kryptonians, and were even more outraged to learn that the majority of the universe lauded their hated enemies while the Dheronians were cast out and left to rot, simply for demanding what was "rightfully" theirs.
After aeons of wandering, the Dheronians were discovered by the New God Darkseid, who offered them resources and spaceships that replenished back into their full military strength with promises of enacting their revenge on the Kryptonian race in exchange for worshiping him as their god, which they eagerly obliged. Darkseid made a decree to the Dheronians to hold their revenge back until the time was right, which then that every Kryptonian man, woman, child, animal, or machine will not be allowed to live. Their revenge struck when the Krypton-Shi'ar War ended, with Krypton's Planet-Shield dropped in peacetime, allowing the Dheronians using Boom-Tube technology into teleporting a series of probes directly into Krypton's core, generating a force-field that prevented heat from dissipating to the surface and causing the chain of events that led to the destruction of Krypton and its people.
It wasn't until decades later that the Dheronians were broken from their rejoice that they heard news of the Kree and Skrulls that had been defeated by the Kryptonian Battlestation Sentrius and learned that only three Krypontians and one half-breed - Superman, Supergirl, Krypto, and Power Girl - were living on Earth. Realizing that their decree is left unfinished, the Dheronians, led by Tyr'ell, proceeded in eliminating the survivors along with Earth for harboring their hated enemies. However, their first attack, which was brought about by manipulating Maxima into trying to make Superman her husband and simulating Earth's destruction as Krypton's, ended in failure- particularly thanks to the light-manipulating members of the X-Men- with Tyr'ell committing suicide to prevent the Justice League, X-Men, and Avengers from learning about Darkseid. Following this failure, Tyr'ell's son became the Dheronian's new leader, upon Darkseid's command. Despite the failure, Darkseid was unconcerned, as he had anticipated it and had, in fact, planned it, though the exact reasons for this have yet to be revealed.
The Dheronians appeared in Superman: Earth One, written by J. Michael Straczynski. The Dheronians exist in the Earth-1 reality and were bitter enemies of Krypton that fought several wars, which ended when a Dheronian war machine, designed to destroy Krypton's core, was provided by General Zod.