Xiomorn

Xiomorns are a race of primeval elemental outsiders from the Plane of Earth, best known in modern Golarion as the Vault Keepers. Among the oldest known life forms, Xiomorns travel to young planets in the Material Plane to conduct experiments into the nature of life and evolution, though they have little interest in the indigenous lifeforms of these worlds aside from their roles in the Xiomorns' experiments. Planets visited by Xiomorns feature strange ruins and great vaults that hold strange ecosystems, such as the vaults of Orv within Golarion's Darklands.

History
While much of the history of the Xiomorns has been lost, it is known their expansion and experimentation brought them into conflict with an even older race: the Aboleths. Though Aboleths and Xiomorns shared similar interests, they differed in ideologies, and their primordial empires turned to war. The Xiomorns lost this war, and faced with extinction, most of their race fled Golarion.

Society
Xiomorns were divided into two castes: the Vault Builders and the Vault Keepers. The mythic Vault Builder were masters of crystalline magic, able to create and shape both life and terrain with their minds. They ruled over their lesser kin, the Vault Keepers, who were tasked with maintaining and protecting Xiomorn experiments.

Only the Vault Builders could use the power of the vault seeds to create new vaults. Vault Keepers who tried to tap into the seeds' power were unable to control the magic, creating spectacular backfires such as the one that created the Emerald Spire in the northwestern River Kingdoms.

Religion
Xiomorns considered the demigod Ayrzul to be their race's patron, and the Fossilized King in turn sees the race as his favoured children.