Krypton

Place

Planet Krypton

Destroyed home of the race known as Kryptonians, and formerly the seat of the Kryptonian Hegemony.

A produce of Celestial engineering, Kryptonians were as a species astonishingly powerful. A rare genetic divergence allowed them to absorb radiation and use it as mitochondrial fuel. Tougher and sturdier than many races, Krypton began expanding outwards from their home mere decades after inventing space travel.

Beyond the dim reach of their sun, Kryptonians discovered they were virtually invulnerable. Little could kill them, or meaningfully hurt them. They turned from an exploratory force to an invasion force overnight. In the space of fifty years, Kryptonians had conquered a dozen neighboring sectors and were engaged in full-scale war with Oa, effortlessly crushing legions of their Manhunter robots. A single Kryptonian was an army. Ten of them in one sector was a war crime. Needing neither materiel nor rare earths, the Kryptonians could fly across the stars without even needing spaceships.

Oa, their chief rivals, attempted three gambits to stop the Kryptonians. The first was the formation of the Green Lanterns, more flexible and cunning than their Manhunter robots. The second was to dim Krypton's main star, turning it from a small but mighty blue star into a dull, weak red star. The third was to create an army of warriors, physical equals with Kryptonians but armed with magical weaponry. For this, they turned to the Demiurge, a proto-sapient mass of energy in deep space, and the refugee First Gods living there. Together, Oa and the First Gods pushed the Demiurge into true self-awareness, and from that evolution came the hawkish, proud warrior kingdom of Asgard.

Finally, their long-term gambit: a genetic plague, slow incubating and difficult to detect. Krypton did not know it was poisoned until fertility rates abruptly reached 0%. In the space of a decade, no new Kryptonians were born, to a species with an already low birth rate. In the space of a century, the Kryptonian population dropped by 99% due to war and attrition. Tey huddled on their home world of Krypton to try and find a solution. Oa seeded their asteroid belt with irradiated rocks formed from chunks of a neighbor planet, creating a web of Kryptonite that prevented independent space flight.

Krypton turned to science, and the few survivors rapidly made up for centuries of their intellectual dark ages. Though they were unable to repair the damage to their main star, they built domes that mitigated the worst of the lethal Kryptonite and used cloning techniques to manufacture new Kryptonians. For thousands of years they limped along, frequently subverted and sabotaged by Oa. Even their attempts at technology were stymied-- their Brainiac AI was corrupted and sabotaged.

In the end, one Kryptonian scientist make a desperate gamble. Jor-El boarded the last of their hyperspace ships and made a desperate quest to locate the ancient cousins of the Kryptonians: the lost colony of Kherubim.

He found their descendants. Not on the planet Khereb: but on Earth, in the Royal Family of Wakanda. From their ancient Kherim DNA he was able to engineer a cure for the Oan sterility plague, and raced home in time to discover the Oans had implemented their last failsafe. With their sun on the verge of exploding, Jor-El and his brother were able to use the gene therapies and help their wives conceive one child each. The children were born as gravitational waves pounding Krypton, and the children were placed into bio-suspension pods and they were sent to Earth, the last Son and Daughter of Krypton.

With the children vanishing into distant space, Krypton's main star exploded and the entirety of the Kryptonian race passed into history.