

The JLA and Avengers teamed up to stop him. Krona intended to cause a new Big Bang he would learn the secrets of. The Grandmaster had trapped Krona between the universes using the 12 items of power, but Krona began accelerating the process, threatening to destroy both universes. After he killed Galactus, Krona wrecked havoc with reality. Although Grandmaster won the game, Krona became furious and mortally wounded him, then proceeded to summon Galactus to learn the origin of the universe from him.

The two cosmic beings forced the Justice League and Avengers to gather many powerful relics across both worlds, competing against each other to gather the most. There he met the Grandmaster, who challenged him to a game for the fate of that universe. In his search for the origin of the universe he destroyed hundreds of realities until he came to the Marvel Universe. Krona was the main antagonist of the crossover comic event between the Justice League and Marvel's Avengers. The Oans severely punished Krona for his misdeeds, turning him into a bolt of energy and sending him to forever wander the cosmos. At this same moment, the Anti-Matter Universe was created, unleashing evil into the cosmos thus, the Monitor and the Anti-Monitor were born. The universe then infinitely replicated itself. At that instant, his machine exploded and the universe was shattered. As he watched time peel away, Krona caught a glimpse of the hand of creation depositing the speck that would become the entire cosmos. Krona constructed a machine capable of piercing the temporal barrier and viewing the beginnings of time itself. Ten billion years ago, Krona, one of the most brilliant of all the Maltusian scientists, decided to break the ancient edict and probe the origins of universe itself. Krona is responsible for the creation of the Anti-Monitor and the existence of evil itself, making him the overarching antagonist of the Pre-Crisis and Crisis era of the DC Universe. However, Krona swore revenge against the Maltusians and promised to return to wreck havoc against all they've created. Out of guilt for Krona's crimes, the Maltusians split into three groups, being The Guardians of the Universe, the Controllers, and the Zamarons. For committing the ultimate taboo of tampering with reality, his fellow Maltusians banished him from their ranks and transformed him into a formless energy meant to circle the entire multiverse. However, the machine malfunctioned and resulted in the creation of the multiverse and the Monitors. He was once a Maltusian Guardian that, in his endless curiosity to study and learn the secrets of the universe, created a machine which allowed one to travel back in time and witness the Big Bang. He is the arch-nemesis of the Guardians of Oa. He first appeared as a major antagonist in Green Lantern Vol.2 40, before returning as the main antagonist of the JLA/Avengers storyline, the main antagonist of War on the Green Lanterns, and the overarching antagonist of the Green Lantern franchise. Krona is one of the main antagonists in the DC Universe mythos, serving as the overarching antagonist of the entire Pre-Crisis continuity.
