Krona Kruneeghol belonged to the ancient Maltusian race and, as a scientist, sought to create intergalactic order, believing the only logical way was through knowledge. His thirst for understanding consumed him as he implemented perverse experiments to the detriment of the cosmos. Krona's ideas often clashed with those of his fellow Maltusians, including his protest over his brethren's contempt for emotions during their progress into becoming the Guardians of the Universe.
At some point, Krona was attacked by the ManHunters, the emotionless, robotic force created by the Guardians of the Universe, and he was able to fend them off. Afterward, Krona believed that the Manhunters are flawed, as an emotionless police force, and decided to prove his theory by discreetly reprogramming them to commit a massive genocide of Sector 666; specifically the planet Ryut, where only five individuals, known as the Five Inversions, survived the massacre, and founded the Empire of Tears. Among those five was Atrocitus, who would later found the Red-Lantern Corps, swearing vengeance on the Guardians, as he mistakenly believed them responsible for the devastation of his world. The massacre also caused the Guardians to abandon the Manhunters and form the Green-Lantern Corps.
Krona continued his forbidden experiments that involved witnessing the beginning of time itself, which was considered by the Maltusians a great taboo. He succeeded in his experiment and managed to glimpsed the hand of creation depositing the speck that would become the entire cosmos. His machine exploded at that instant, and the universe was shattered, causing the creation of the Multiverse as the universe replicated into an infinite number of parallel universes. At this same moment, the Antimatter Universe was created, unleashing evil into the cosmos, and giving birth to the Monitor and the Anti-Monitor. Krona's actions finally caught the attention of his fellow Maltusians, who expelled him from their ranks and punished him for his crimes by converting him to a state of energy, which was sent to circle all the universe for eternity. It was the actions of Krona that caused the Maltusians, who felt guilty for not having stopped Krona early on, to split into various groups (the Guardians of the Universe, the Controllers, and the Zamarons). Though banished, Krona vowed revenge and could only wait an opportunity to escape.
Following Krona's banishment, a map belonging to him was left behind on Maltus which highlighted a great of source of power on the world of Okaara. This map was discovered by Larfleeze and his band of thieves which led them to uncovering the Orange Lantern Power Battery.
Krona would eventually escape his fate, and he later tried to start his experiment all over again, since the original machine had exploded before he could finish watching the universe being created. He was stopped by the Green-Lanterns of Earth, Hal Jordan and Alan Scott, and banished into his energy form again.
Eventually however, Krona's energy form somehow reached the dimension where the souls of the dead in the universe await their passage into their final residences. This realm was ruled by a being called Nekron, Lord of the Unliving. Because of the paradox of an immortal now being in the Realm of the Dead, a rift opened between the dimensions, which allowed Nekron to see the universe of the living. Desiring it, but being too large to pass through the gap, Nekron instead recreated Krona as an undead being of enormous power.
Given an army of similarly-restored spirits, Nekron sent Krona to kill the Guardians, so the rift would open more. Krona accepted Nekron's commission, because part of Nekron's plan involved collapsing the universe so as to recreate it according to his own desires; this would give Krona the chance to see a universe being born. Krona and his minions succeeded in killing some Guardians as well as several Green Lanterns while destroying the Central Power Battery to preclude the Lanterns recharging their power rings.
Although Krona's subsequent attack was powerful enough to shatter the morale of the Corps, Hal Jordan managed to inspire and rally his fellows to attack Krona with the remaining time of their rings' charge. Krona was defeated when Jordan entered the realm of the dead and incited the spirits of the recently-killed Lanterns to rebel against Nekron. This gave the Guardians enough time to banish Krona into the dead realm and close the rift while the spirit of Jordan's predecessor, Abin Sur, helped his successor escape the realm.
While still an entropy-being, still trying to discover the secret of universal creation, Krona used his probes to destroy several dimensional universes. Arriving in the Marvel Universe, Krona agreed to a cosmic game with En Dwi Gast, the Grandmaster], who stopped his probes, after the Grandmaster stated that there is a being in his universe who had survived the Big Bang. In exchange for not destroying universes, the Grandmaster offered Krona to play a new game; in which involved two teams from each universe, the Justice League and the Avengers, to seek out twelve items of great power scattered throughout both universes. The Justice League represent the Grandmaster, and the Avengers represent Krona. Should Krona's team win, the Grandmaster would give Krona the knowledge he sought, in return for not destroying his universe.
But the game resulted in a victory for the Justice League, due to the heroes having figured out the nature of the game. Krona attacked the Grandmaster out of anger and absorbed his knowledge, which resulted in his finally obtaining the secret he sought from the cosmic entity Galactus, whom he killed. In spite of Krona's success, he fell into a trap engineered by the Grandmaster, which imprisoned Krona between the Universes, by using the items of power to merge the universes together. However, Krona gained control of the items and continued his onslaught, seeking to destroy both of the two Universes, in order to create a new one the creation of which he could watch at first-hand. The Justice League and Avengers heroes made an assault on Krona's base, (which was built from the remains of Galactus), and Krona responded by summoning an army of brainwashed villains against the heroes. Even with Superman wielding Captain America's shield and Thor's uru hammer Mjolnir, it was Hawkeye and the Flash who finally stopped Krona, imprisoning him into a "cosmic egg" from which a universe will be born in about a trillion years. The cosmic egg was kept and studied in the JLA's Watchtower.
The cosmic egg containing Krona was later stolen by Despero and used as a power source by Enigma of the Antimatter Universe and Morgaine le Fey to reshape reality as the Dark Trinity, using the egg as a conduit to warp the world with magic. When the spell failed, Krona was freed. Following a lead he found during his confrontation with the Grandmaster (stating that all universes have awareness and thoughts of their own), he contacted the Controllers to help him contact the New Earth universe's consciousness. The Controllers were skeptical, and instead attempted to restrain Krona and study his energies. Enraged, Krona destroyed the laboratory planet of the Controllers and found the planet's consciousness, "freed" from its prison of matter. Krona then set out to do this to as many planets as he could so as to ultimately bring war upon the Universe's consciousness itself.
Krona was then approached by the Dark Trinity seeking his power to fend off the returned Trinity (Superman, Batman, and Wonder Woman). Morgaine offered the planet Earth's consciousness in return, intending to replace it with the soul of Enigma's daughter. Krona accepted and this resulted in a battle between him, the JLA, Justice Society of America, Titans, Teen Titans, the God-like trinity consisting of Superman, Wonder Woman and Batman, and other various heroes, aliens, and villains. During the height of the battle, Krona was imprisoned, but was set free by Morgaine, who had finally snapped, claiming that if she could not have the world, then nobody would. Following that, Krona unleashed his powers and destroyed the Earth.
Moments after Earth's destruction Krona encountered its essence, the Worldsoul. Krona inquired about the law of universes, wishing to know how the Worldsoul and other entities like it function and exist, hoping to learn of some higher plan or design. However, he was horrified to learn that the Worldsoul has no actual function other than to simply exist, resonate and, most importantly, to feel, to share in the positive emotions of every life form that dwells upon its surface, at one with the Universe in a Great Dance with the other souls of worlds. This explanation, such as it is, defied all logic and science Krona had studied, and he believed this rendered himself and his entire life, in effect, pointless. In a fit of rage, he attempted to destroy the Worldsoul, but was stopped by the Trinity, who had survived the destruction of Earth. Combining their powers with that of the Worldsoul, they imprisoned Krona and re-formed the Earth, restoring everything and everyone to the way it was prior to its destruction. Krona's ultimate fate was to be remade as the Worldsoul of an alternate Earth, this time imprisoned for all eternity.
In the wake of Nekron's defeat during Blackest Night, Krona escaped his imprisonment and returned to his universe. He went to work again, now collecting all of the Emotional Entities and taking control of the Green-Lantern Corps. The first act of Krona's plan occurred with his abduction of the fear entity Parallax and the imprisoning of the creature within the confines of an ancient temple, marked with the symbols of the Emotional Spectrum.
Krona then proceeded to remove Ion from Sodam Yat, effectively turning Daxam's sun from yellow back to red and killing hundreds of Daxamites in the process. Krona also worked with the suicidally insane Hank Henshaw, telling him that enslaving and altering the qualities of the Alpha-Lanterns would restore his mortality and would also lead to the destruction of the Green-Lantern Corps, and of the telepathic Zardor, in Henshaw's own plot to brainwash rookie members of the Green-Lantern Corps for his own purposes.
Krona ultimately made his appearance before Hal Jordan, Nicole Morrison, Larfleeze, Saint Walker and the Indigo Tribe, seeking to obtain both Adara and Proselyte for his entity collection. When confronting Jordan and the others, Krona revealed that, prior to his banishment by the Guardians of the Universe, he was the caretaker responsible for protecting the entities, and that is why he now could control them and the abilities they possessed Despite the efforts of the New-Guardians, Krona was able to captured all the Emotional Entities, and took them into the lost sector.
War of the Green-LanternsEdit
With the powers of the entities, Krona returned to Oa and used all the entities but Parallax to possess the Guardians. Krona placed Parallax into the Central Power Battery and in doing so, restored the impurity throughout the Green Lantern Corps, and caused any Green Lantern to lose their free will and become slaves to Krona. Those who had been under Parallax's control in the past, however, were immune to Parallax taking over them again: specifically Hal Jordan, Guy Gardner, John Stewart, Kyle Rayner, Ganthet and Kilowog.
The remaining Green Lanterns, sans Ganthet and Kilowog, were able to fight back by using the rings of the other Lantern Corps and freed the Green Lantern Corps, at the cost of killing Mogo. While the Green Lantern Corps were battling the possessed Guardians, Krona battled Hal Jordan and Thaal Sinestro. Despite Krona's greater power, Hal Jordan has a sudden burst of will that he unleashed on Krona, which killed him and removed the Emotional Entities from the Guardians. Afterward, in spite of Krona's heinous actions, the Guardians decided to honor their former brethren, along with the other fallen Green Lanterns. However, Guardian Ganthet turned over Krona's corpse to the Red Lantern Atrocitus as part of a promise they had previously arranged.