The Grey Heads

Run a number of schools and research teams as a scam. Forgers, con men and snake-oil salespeople. Leader known as 'The Scribe', a warlock or wizard, possibly Dragonborn. Based in Naugor, Pilaan.
The deeper, darker bit of it is that the Grey Heads aren't entirely a con, but what research is being done is of the profane, necromantic variety. That the Grey Heads sometimes procure fresh corpses from the workhouse graveyards is a common secret.
Vaguely conforms to the soiety of Brilliance, but not limited to the underdark and are a bigger group obviously. Certainly more amoral than evil, but strives to not pass judgement except in the most extreme of circumstances.

Structure

Unknown, but thought to be organized loosely around a university or school structure.

Public Agenda

The general scam is to purport to notice magical ability in the victim, to coddle and stroke his ego and then offer a class at the university - but not the actual Arcane University of Khazigur; once payments are procured, the recruiter disappears with the money.

Type

Illicit, Front