Kor ra Ath, Fury of the People, stands apart from among all the great heroes who appeared among the Kaaradi for two reasons: was born an Ath, and he led his people to the Kaarad, thus becoming the First Kaaradi.
Kor ra Ath was born during the Age of Myths, if the Kaaradi's legends are to be believed (and after some corrections thanks to the Kun'dra and their great knowledge of this era) roughly a thousand years before the end of this mythical Age. At this time, the numerous tribes of the Ath were waging a war of survival against the human tribes on the continent which would be known as Täjara. The reasons behind this war are all but lost in time, but it is probable that the humans were disgusted by the Ath physical features, which where a combination of both humans and non-humans (such as their eight canines, almost fangs, sharp ears and smaller size). Anyway, the various human tribes where fighting to destroy the Ath, repelling them near the mountains in the east of the continent.
When Kor was born, it is said that his cries weren't of pain, as other newborns, but of fury, hence his surname (Kor meant Fury in atha). Since he quickly demonstrated a far greater strength and stamina than any other child among the Ath, he was given the full name of Kor ra Ath (Fury of the People) and at the age of ten, he was leading his tribe against the humans, killing their warriors and enslaving their children. He also wrestled against the leaders of the other tribes of Ath, and at the age of sixteen, two third of the tribes were under his command.
Then, while the earth was shaking and the world changed, Kor ra Ath was plagued by dreams and nightmare where the Dragon God (today called Dura'Turakas by the Kaaradi) warned him of an incoming danger from below the earth. He then prepared his people, even if the tribes who escaped his authority believed that he was insane when he talked about Those from Below and their will to consume the world. Sadly, Kor ra Ath was proven right when the aberrations launched a massive invasion of the surface after their birth during the Corruption of the Ashendants.
Kor ra Ath, following the urging of the Dragon God then led his people into the Underworld, in the newly formed Kaarad, where he discovered the four Monster-Gods which are older than the Kaaradi and the Records of the Ashendants. He then pledged loyalty to the Gods and swore that he and his people would endure the Eternal Vigil to defeat Those from Below and their Gods.
By doing so, he and his people where transformed by the Monster-Gods, their skins turning to grey tones as a proof of their pact. It was how Kor ra Ath became the first of the Kaaradi.