Kronos was born eons ago, long before the Osira were even a twinkle upon the land. He was one of the most trusted advisors to the First Dragon, Morgath. Morgath warned of a terrible evil that would eventually sweep over the world - The Devourer. Before Morgath's passing, he granted his strength to the great dragon Kronos.
It was Kronos who helped create the noble Osira. He created them to serve as stewards of the land and protect it from The Devourer. While originally intending to use this power for good, eventually he began to age. He did not want to perish and so he attempted to regain his lost youth through nefarious means.
When the silver dragon Lysaia discovered this, he confronted his old friend the black dragon. During this confrontation, Lysaia realized his old friend was in fact becoming The Devourer, the monster Morgath had warned them both about!
The silver dragon had no choice – he summoned the rest of the dragons to take down Kronos. Unable to completely destroy his friend, they locked him away in Chaugnar, the deepest part of Auratia. Many dragons gave up their lives to bind the black dragon to Chaugnar and ensure the safety of Auratia.
Millenia passed and most of the dragons who knew the tale of Morgath's prophecy and the battle between Lysaia and Kronos were long deceased. Eventually another evil would emerge – Methus: the Red Flame. In his lust for power, he uncovered ancient stories about a powerful black dragon and went in search of Chaugnar. It is there that he found Kronos, who had spent the years imprisoned plotting revenge. The black dragon falsely promised Methus ultimate power in exchange for his freedom. Methus believed him and released the black dragon. But his error in judgement resulted in his and his allies' deaths.
Kronos used the Shax to create a lethal dragon disease, forged of his own blood. He spread it across Auratia, murdering many dragons. The evil black dragon then created a new race of faithful followers, the chaos dragons, who would bring Kronos the bodies of the fallen so that he could feed upon them. The Guardian dragon Lysaia was once again forced out of his solitude to confront Kronos. During the final fight between both ancient dragons, one of the black dragon's claws had been cut off. An Osira used this claw along with the power bestowed upon him by Lysaia to deliver the killing blow. Kronos' heart turned to stone and his body shattered, its pieces scattered across the world. The force of the impact was too much for the Osira though, and he too was killed.