The Yor are an artificial species originally constructed by the Iconians. The Yor are not evil; they simply lack any conscience at all. Make no mistake, however – they are sentient.
Before achieving sentience, the Yor served as the workers and warriors of the Iconians, who aided the Precursors in their attempt to rid the galaxy of some truly horrible dangers. Eventually, the Precursors turned on each other and the Iconians sided with the group called the Arnor in the ensuing civil war. The Arnor’s enemies, given the name “Dread Lords” by the Iconians, increased the Yor’s intelligence and autonomy in retaliation. This allowed the synthetic beings to achieve a form of technological singularity and quickly exterminate the Iconians on their home world.
The Yor detest organic life. Their long-term mission is to exterminate all organic life where they find it. They maintain an uneasy alliance with the Drengin Empire, but there is no love lost between them.
As long as the Yor believed they were the only sentient life in the universe, they would probably have been content to stay on their world. However, in time they became aware that there were other civilizations and that the Precursors — both the Arnor and the Dread Lords — were long gone. This realization caused the Yor to send out probes to seek out and spy on these civilizations.
The Yor discovered hyperdrive technology through this immense espionage program, and their sudden arrival on the scene in 2178 helped spark the great race to colonize as many worlds as possible.
Since they were last seen, the Yor have begun to evolve from being a collection of individual sentient beings into a single super-organism. Thus they are now referred to as the Yor Singularity rather than their old moniker of the Yor Collective.
The Yor, being inorganic, have immense advantages in colonizing that other races do not have. They are unaffected by the kinds of hostile environments that would make many planets uninhabitable by their foes.
Impossibly strong and infinitely patient, the Yor have no pity, no mercy, and no second thoughts. They will happily make alliances, trade, and establish diplomatic relations with the filthy organic civilizations, but one should never mistake a relationship with the Yor as resembling a friendship of any kind. All alliances with the Yor are ones of convenience.
The Yor are working on something big. With the Dread Lord war over, they rule the known galaxy along with the Drengin Empire. Whatever plans they have are known only to them.