Kryptonian (Earth-149)

Kryptonians are a naturally powerful scientific and warrior sentient species who were nearly all obliterated by Darkseid in the distant past during the Pangenic Wars. Earth's greatest defenders, Superman and Batman are Kryptonians, being the planet were the race will rise again, by means of the two heroes' sons.

Origins
The Kryptonians are a both scientific and warrior race who, since ancient times, have lived a violent lifestyle, where they attack numerous planets to build up wealth and goods. The Primordial Kryptonian appeared approximately 3,000,000 years prior to the current events, approximately 238 Before Age, and is described by Batman as a Kryptonian who could only retain his status in the transformed state. He appears to have lost control and gave in to his destructive primitive desires and destroyed himself with his own power.

Asari-Kryptonian War
A small group of Kryptonians eventually found their way to the planet who would be named Krypton in Age 550, and the history of the Kryptonians predating their conflict with the Asari was revealed and discussed by Batman.

Shujinko describes the Kryptonians as a group of barbaric aliens who shared Krypton with the Asari. The Kryptonians lived in great cities, while the Asari were forced to live in underground fortresses, employing advanced technology to the Kryptonians' bidding. One day however, the Kryptonians attacked, vowing to conquer the Asari's underground cities, and to extinguish the race. This sparked a ten year long war.

It is later revealed that when the Kryptonians arrived on Krypton, they were welcomed by the Asari. The Asari survivor, Liara, then described the horrors of the war in a similar fashion to the one Shujinko tells. However whilst explaining, Batman stated the Asari used the Kryptonians as slaves, making unclear the real conditions of the war.