Oa started out as a peaceful planet with citizens of vast mental abilities and ambition. One of them, Krona, developed a screen to witness the dawn of time and caused an explosion on Oa. He was then sentenced to live forever in energy form. What happened during that explosion was the beginning of the Multiverse and all of the multitudes of its universes. Once the Oans took it upon themselves to fight for justice, some believed that they should destroy ALL evil. The other Oans did not agree and a civil war began. The ones of malevolent nature left for the dimension of Qward and sought the means to become all-mighty. In this universe, the Anti-Monitor was born on one of the moons as an excess of great energy taking form. At that same time in the positive matter universe, The Monitor was born of similar origin.
Soon the Anti-Monitor took over Qward by mere force and created a legion of troops with the power to throw lightning bolts. These people are called the Thunderers. Those of the Thunderers that proved to be his most trusted and powerful were then altered into living Shadows. Once he sensed The Monitor in the positive universe, he began a 1,000,000,000 year long war with him, which ended in both of them losing consciousness.
After 9,000,000,000 years of inactivity from either monitor, Pariah came up in his universe. Being the greatest scientist of all time, he sought to learn the secrets of the origin of the universe. Despite his universe's council's objections, he created an anti-matter cube with which he safely observed the origin of the universe. This origin is a giant hand reaching from an infinite abyss and forming a new universe. While observing this, the Anti-Monitor and The Monitor were freed and the Anti-Monitor converted the anti-matter into energy and used it to destroy Pariah's universe. After destroying this universe, he drained its energy once again and became even stronger. Along with this, the destruction of a positive matter universe caused the anti-matter universe to expand and make the Anti-Monitor even stronger. With this knowledge in hand, the Anti-Monitor set out to destroy all of the positive matter universes and, therefore, make himself as powerful as possible. During all of this, Pariah was alone for millions of years in his anti-matter chamber.
Crisis on Infinite Earths
Once The Monitor realized what the Anti-Monitor�s plan was, he set out to prevent it. He endowed Pariah with the curses of immortality and being transported to every universe at the moment of its destruction. While doing what he could to delay the Anti-Monitor, The Monitor set up a series of towers that would protect Earth-One and Earth-Two from destruction, as well as Earth-S, Earth-X, and Earth-Four. The Anti-Monitor did not know this, but in manipulating The Monitor�s confidante, Harbinger, to kill The Monitor, this powered the machines to work and the two universes were safe from his grasp. In an attempt to destroy the towers, the Anti-Monitor sent his shadow legions to destroy them, but that plan was thwarted by both Earths� heroes and villains. One of these villains, the second Psycho Pirate, switched sides and joined the Anti-Monitor in hope of a universe to manipulate the emotions of. The Anti-Monitor also reconfigured the Red Tornado to do his bidding for a short while as well as give the Flash (Barry Allen) to Psycho Pirate to play with his emotions.
Once the Monitor was killed and the towers were powered up, both Earth-One and Earth-Two, along with all of time itself became connected at one moment in time. To please Psycho Pirate, the Anti-Monitor enhanced his powers and allowed him to manipulate all of Earth-S, Earth-Four, and Earth-X. After causing much havoc and betrayals, Psycho Pirate was thwarted by Harbinger and he lost much of his power. Then Earth-One and Earth-Two's heroes entered the anti-matter universe with the aid of Alexander Luthor. Alex is the son of Lex and Lois Luthor of Earth-Three, who was saved and endowed with control over positive matter and anti-matter. This enabled him to send Earth's heroes safely to the Anti-Monitor's universe. After they arrived at his citadel of living rock, they fought their way through to the core where Supergirl combated the Anti-Monitor. He had not collected much anti-matter recently, so he was very vulnerable and nowhere near so strong as he could be. After having his outer shell crushed by Supergirl, he was loose energy that needed to be contained. However he concentrated all of his energy directly at Supergirl and killed her while she destroyed the core and entire ship. He barely escaped in an escape pod, but both the Anti-Monitor and Earth's heroes escaped. The Anti-Monitor returned to his other ship of living rock and the heroes returned to Earth-One, which was now separate from Earth-Two and no longer of one time.
Upon returning to his citadel, the Anti-Monitor forgave Psycho Pirate because he had nobody else to pick from at the moment with the ability to manipulate emotions. He also returned to oversee the near completion of his ultimate weapon, the anti-matter cannon, which will destroy the remaining five universes once and for all. All this time, the Flash has been waiting and concentrating on the proper moment to attack, which was then. He easily got out of a sticky snare and beat Psycho Pirate into submission. After getting his cooperation, the Flash ran the Psycho Pirate around the entire citadel and had him manipulate the Thunderers to turn on the Anti-Monitor and attack him, which they did. While they did so, the Flash entered the core of the anti-matter cannon and reversed the energy flow out of it. Upon doing so, the Flash exceeded the speed of light and was destroyed along with the cannon. After easily dispersing the atoms of his Thunderers, the Anti-Monitor realized that his weapon was destroyed and that he would have to take a more abstract approach. He drained the anti-matter energy of over 1,000,000 worlds and used it to travel back to the dawn of time, and Pariah followed due to his curse.
Eventually after fighting a mini-war with the villains of Earth, its heroes and villains, along with a Superboy from a destroyed Earth-Prime, barely reached the dawn of time through a series of manipulations of powers, one of which was the Spectre powering their journey. Once they reached the Anti-Monitor, they attacked him with all of their power, but to no avail. He drained all of their life force and used it to attempt to alter history from the dawn of time. It turns out that the hand that Pariah and Krona witnessed at the dawn of time was the Anti-Monitor's, but this time he was confronted by the Spectre. Being backed up in power by all of the most powerful sorcerers there are, the Spectre brought an end to the Anti-Monitor's meddling in time.
Upon slightly changing time, the multiverse became only two, the positive matter and the anti-matter universes. Earth�s heroes and villains that were present at the battle at the dawn of time were revived and some were placed back into the timestream while some others were there without a past except to the others that were at the dawn of time. The Anti-Monitor was also sent back to the anti-matter universe, his origin. Upon returning, he deployed literally countless shadow creatures to take the only Earth by force, but he also brought only the Earth into his universe. Upon arriving, Earth�s heroes are greeted by the Anti-Monitor and they attack him. Also at this time, the world�s greatest sorcerers, except the Spectre, have contained all of the shadow creatures into a mystical sphere. However, as the heroes start to lose in their assault on the Anti-Monitor, they deploy their secret attack set up by Harbinger, Alex Luthor, and Pariah. Alex uses his powers to drain as much anti-matter energy out of the Anti-Monitor as possible while the new Dr. Light, a female hero, drains the energy from a star. Then all at once, Dr. Light with the power of a star in her body, all of the heroes, Alex, and Harbinger attacked the Anti-Monitor and crushed him into a floating rock. Believing the Anti-Monitor to be dead, many of the heroes left the anti-matter universe through Alex, leaving for the most part Supermen of Earth-Two and Earth-One, Superboy-Prime, Lady Quark, and Alex Luthor.
In an attempt to catch them off guard, the living Anti-Monitor consumed the energy in his shadow creatures and blasted Earth-Two's Wonder Woman in nothing (He actually accidentally reversed her time and she went through a rebirth). Then Superman of Earth-Two knocked Earth-One�s Superman and Lady Quark back into the positive universe through Alex and followed up with an attack on the Anti-Monitor with Superboy-Prime. At this moment, the Anti-Monitor became weakened and it was revealed that the sorcerers that contained the shadow demons poisoned them and this, in turn, poisoned the Anti-Monitor. In this moment of weakness, Superman of Earth-Two and Superboy-Prime physically attacked the Anti-Monitor and hurled him once again into the rock. Then they kept pounding on the rocks, but he still kept coming back and started to squeeze the life out Superman-Two and Superboy-Prime. At this moment, Darkseid decided to interfere and used Alex as a conduit to blast the Anti-Monitor with an energy beam from Alex�s eyes. He was then sent hurtling into a star and his crust finally gave out and his energy form became all that was left of the Anti-Monitor's self.
In his last suicidal attempt to bring Superboy-Prime, Superman-Two, and Alex with him, the Anti-Monitor launched himself as an energy sphere from the star, but met his final and ultimate demise as Superman-2 shattered him into molecules of incoherent energy. He truly did die in this last attempt of murder, and is only remembered by those that were at the dawn of time and/or the battle in the anti-matter universe. Even though he died, it was too late for any of the remaining people to return to the Earth, so they went to an alternate dimension and stayed there for years with Lois of Earth-Two.
Superman and Lois Lane of Earth-Two, Superboy-Prime of Earth-Prime, and Alexander Luthor, Jr. of Earth-Three, from their home in the hidden pocket universe, were revealed to be observing the events of the newly-formed universe, as well as the actions of its heroes. Upon observing the events leading up to Infinite Crisis, the heroes returned to the universe in an attempt to restore Earth-Two's existence, at the expense of Earth-One.
The Anti-Monitor's remains were then used as part of a tuning fork, similar to the one's used during the first Crisis. The tower then created the vibrational frequency that Earth-Two was on prior to its nonexistence, which in turn recreated Earth-Two with no visible expense to Earth-One, save the movement of characters who originated on Earth-Two to the recreated Earth-Two. Alexander Luthor then recreated the other Earths with his tuning fork, with their respective heroes forcibly migrating to said Earths. Superboy-Prime (followed soon by Bart Allen) then returned from the Speed Force wearing what appeared to be select elements of the Anti-Monitor's armor, using it as a yellow sunlight collector. How he obtained it is still unrevealed, although evidence suggests that he built it himself while he was imprisoned and it merely resembles the Anti-Monitor's armour, although whether by intention or coincidence is unconfirmed. Ultimately, the tower was destroyed when Kon-El, the modern Superboy, and Superboy-Prime crashed into it while fighting each other, Kon-El dying in the arms of Wonder Girl as Superboy-Prime fled.
Following the recreation of the Multiverse, the Anti-Monitor was reborn and he has been fueling Sinestro's ideology since the return of Hal Jordan, acting as the Sinestro Corps' "Guardian of Fear." His body was rebuilt by the Manhunters, and in addition, he recruited Superman-Prime, the Cyborg Superman, and Parallax, who was using Kyle Rayner as its host, along with Sinestro as his 'heralds'.
During the war between the Sinestro Corps and the Green Lantern Corps, the Anti-Monitor contacted Cyborg Superman to inquire about the status of New Warworld. The cosmic tyrant stated that he would soon abandon Qward and that he would kill Henshaw for his services, allowing him the peace that had for so long evaded the cyborg.
When the Lost Lanterns made their way to the antimatter universe to save Hal Jordan and the Ion power, they inadvertently stumbled upon the Anti-Monitor in a basement chamber of his stronghold on Qward. He was seemingly experimenting on or torturing the Ion Entity previously inhabiting Kyle Rayner. He proceeded to kill Ke'Haan before the other Lanterns forced him back, taking the Ion entity from the planet and the antimatter universe. The Anti-Monitor pursued the Lanterns for a short while, long enough for Hal Jordan, Guy Gardner, John Stewart and the other Lanterns to learn of his return. Having this vital information, they then leave Qward.
Shortly after, the Sinestro Corps launched their attack on Earth. The Anti-Monitor traveled to the planet aboard New Warworld, and landed shortly thereafter, along with Sinestro. He was attacked by Sodam Yat and other members of the Green Lantern Corps, but the tyrant easily killed two Corpsmen and severely injured the Daxamite Lantern.
The Anti-Monitor begins to siphon the positive matter of New York City to create his traditional antimatter waves. However, he is attacked by the Guardians of the Universe, angry at being impotent during his first war. The Guardians were equally matched against the Anti-Monitor, but only as a whole. John Stewart and Guy Gardner brought down New Warworld and its Yellow Power Battery were detonated next to a trapped Anti-Monitor. Although it succeeded in tearing through most of the Anti-Monitor's armor and weakening him, he survived the explosion. Superman-Prime took this opportunity to have his revenge on the Anti-Monitor for destroying his universe by flying through the Anti-Monitor's chest and hurls his shattered body into space.
The Anti-Monitor's shriveled and glowing form crashed on the planet Ryut in Sector 666, where he is recognized by a dark voice that bids him rise. Too weak to resist or escape, the Anti-Monitor is then imprisoned in a Black Lantern Central Power Battery.
Shortly after his defeat, a female Guardian called Scar, who was burned by the Anti-Monitor, charged Green Lantern Ash of Sector 650 with the task of locating and recovering the Anti-Monitor's corpse. He eventually found part of the Anti-Monitor's helmet, the trajectory of which indicated that the Anti-Monitor's body was oriented toward the long abandoned Sector 666.
Green Lanterns Ash and Saarek discovered the Black Central Power Battery on Ryut and after touching the battery, Saarek reported that their presence has awoken something. The two try to escape just before two monstrous hands emerge from below them to the sound of the battery calling: "flesh." Both Lanterns were dragged into the planet, killing them. It was revealed that the Guardian Scar had died long ago after the Anti-Monitor's attack and, functioning as an undead, caused her to become the Guardian of the Black Lantern Corps. Through her state of death, she made contact with the demon Nekron, who is the one responsible for imprisoning the Anti-Monitor in the black battery as its power source.
When the battery is brought to Earth, the Anti-Monitor stirs within, demanding to be let out. He begins draining the white energies of Dove in order to attempt an escape. The Anti-Monitor is revived as a Black Lantern independent from Nekron's control. Just as the entity was on the verge of pulling himself out of the battery, he is attacked by the various Lantern Corps, who seek to destroy him, thus robbing the Black Lanterns of their power source. Combining their energies, and using Dove as a human bullet, they manage to weaken the Anti-Monitor, who is pulled back into the battery. At the end, the Anti-Monitor was among the few who were brought back to life. He broke free from the Black Battery but was banished back to the anti-matter universe by Nekron.
The Anti-Monitor was confronted by the White Lantern Boston Brand, who was forced to fight the being and damaging him in the process with his White Lantern Ring before escaping, leaving the Anti-Monitor confused by what had occurred. This event led the Anti-Monitor to be curious about the Entity and preventing Deathstorm, the Black Lantern version of Firestorm, in his attempt to destroy the White Lantern Battery and instead commanded him to bring the lantern and as well an army to him. Deathstorm obeyed by bringing the Black Lantern versions of Professor Zoom, Maxwell Lord, Hawk, Jade, Captain Boomerang, Martian Manhunter, Aquaman, Hawkman, Hawkgirl, Deadman and Osiris.
When Deathstorm brought the White Lantern Battery to the Anti-Monitor, his efforts were stopped by Firestorm who, after engaging in battle with the Anti-Monitor and the Black Lanterns, is able to regain the White Power Battery from the Anti-Monitor. Unknown to everyone, the Entity of the White Battery allowed itself to be captured so it could obtain unspecified information from the Anti-Monitor.