Brotherhood of Gix
The Brotherhood of Gix was a group of black mages, led by Jarsyl, that was seeking artifacts in Phyrexia in protection against the atrocities of Urza and Mishra during the Brothers' War on Dominaria.
The mebers of the Brotherhood believed in a afterlife for mechanical artifacts and were influenced by an Yawgmoth Demon who lusted after the Powerstones of Urza and Mishra. Finally they were enslaved by Gix as priests of Yawgmoth. They were instrumental in alienating Mishra from his closest suporters and advisors, like Ashnod, and his subsequent compleation. Unknowing of their affiliation, the Archmandrite of the Ivory Tower invited the Brotherhood of Gix to join the Council of Mages.
There are lots of similarities between the Brotherhood of Gix and The Order of the Ebon Hand, such as cutting of limbs as an honorable thing, which suggests the Tourach might have been a survivor of the Brother's War that fled to Sarpadia.