Seekers of Carmot
The Seekers of Carmot were a sect of mages in Esper that sought the mythical ingredient needed to create etherium: carmot. They were one of the various factions on Alara that were manipulated by Nicol Bolas.
The leader of the seekers is known as the Hieresiarch and the inner circle as the Fellows of the Arcane Council.
Silas Renn and Tezzeret were both members of the organization.