The magus realm's underworld as the home base of the Conclave was home to many factions, some minor factions were ruled by powerful mages or a minor god, some major factions were ruled by a magister or a powerful mid-level god, one of these factions was the cult of the immortals, this faction was an ancient faction ruled by the ageless one, a god so old most had forgotten his name.
The ageless one was a god of aging, resilience, conspiracy and betrayal this god had built around him a solid faction of minor gods and Arcane masters to serve him, the cult of the immortals promised the powerful mages that the ageless one would stop the aging process of the mages so that they could slowly study magic without the fear of a short lifespan.