The Damia

The Damia or Gene-witches are a remnant of the ancient Selenite gene-cults of Luna. Sometime in the Dark Age of Technology the Selenar travelled across the galaxy and established a settlement on the planet that would be later-known as Zion. Isolated during the Age of Strife, this settlement survived the mother-cult's conquest during the First Pacification of Luna and its eventual destruction following the end of the Horus Heresy. Over the millennia the gene-cult pursued its obsession in secret, its science becoming more corrupt and debased until it was a twisted shadow of its former glory.
The Damia and their gene-wrought monsters (later-called Gryphs by the Outremarin) were deemed antak'ya ("non compliant", lit. "resisting") by T'au Water Caste diplomats during the later stages of the Second Sphere Expansion and marked for pacification by the Fire Caste. Before this could be achieved the Damocles Gulf Crusade began and the T'au military had to repel the Imperial invaders. At the conclusion of the Crusade Imperial forces withdrew and the Damocles Gult was declared off-limits for the T'au by the Ethereals, leaving Zion under the control of the fledging post-Imperial realm of Outremer. Ostensibly destroyed by Les Chevaliers d'Outremer and other Outremarin forces, the Damia nevertheless remain on Zion in secret caverns beneath the capital city of Montréal.