Oa

Oa is the home of the self-proclaimed Guardians of the Universe. It is also the source of power for the Green Lantern Corps and the origin of the Martian Manhunters.

The Oans are technologically substantially advanced, cunning manipulators and far-seeing strategists. Oa has no culture except what their armies bring back to them. Oans are cold and merciless, almost universally obsessed with the concept of law and order in the universe.

Oa is one of the five oldest races in the universe. Locked in an endless and eternal war with the Celestials, Oa has been an instigator of many proxy wars and cultural shifts across the galaxy for the last billion years.

The first major play of their endless detente came when they armed a race called the Aspirants with weapons to combat the Celestials. Though the Aspirants were annihilated, it was a provable concept to outfit other races from Oa's advanced knowledge of technology. In response, the Celestials seeded their DNA in lifeforms all across the universe, attempting to 'grow' a new generation of Celestials.

For a time, Oans had begun to analyze and even control magic, in the earliest days of their ascendency. One of their earliest battles was against the forces of entropic necromancy itself, battling the Empire of Tears, an early offshoot of Celestial engineering. Seeing the immensely powerful potential of magic and struggling against such a biased and powerful force, Oa began searching for ways to destroy all magic, forever. They began inventing powerful machines to harness and control magical forces, redirecting those powers or destroying the structure of magic in the universe completely. They successfully destroyed the weft of magic in dozens of sectors-- condensing all that power into a meteor that would become the Starheart. 

One Oan scientist, blending magic and technology, dared to look at the moment when the hand of the Creator deposited the Cosmic Egg from which all reality would flow-- and tried to stifle it, thinking this would stop magic from ever forming. Creation shattered and reformed in an eternity and an eyeblink, and all of Oa found herself forever cut off from the flow of magic called The Source. Mighty though their technology was, Oa was unable to recover from this blow.

Much of understanding magic was more instinct than reason, more art than science, and in this rare instance Oa found they could advance their understanding of a topic no further. This later inspired the creation of the Green Lantern Corps as a power ‘indistinguishable from magic’ and utterly unique in the universe.

The Krypton Detente

The most significant event of the last fifty milennia was the rise of planet Krypton and the Kryptonian Hegemony. The military might of Oa was strained to the breaking point trying to contain them, depleting the entire reserve of their Martian Manhunters. Oa enlisted allies such as the Kree in the battle, and helped the mad god Darkseid tap into the power of the Omega Force.

Oa attempted multiple strategies, but their most far-reaching one was the creation of the Demiurge. A sentient magical presence, the Demiurge was guided into producing armies to fight Krypton. The most prominent of these New Gods was Buri of Asgard, who led the armies of Asgard to crushing victories over Krypton.

The military rout was launched along with genetic plagues, radioactive bombardment, and even dimming Krypton's main sequence star. Sabotaged from within and without, Krypton passed into history when the last of the Kryptonians saw their sun go nova as the Oans implemented their final sanction.