Simas has white hair and a snow-white beard.
With his mild personality, Simas is described as "water to Nautzera's fire." During the Quorum meeting at which Achamian is sent on his mission to discover the target of Maithanet's Holy War, Simas reveals that he has told the Quorum about Achamian's former student Paro Inrau, which Achamian feels is a great betrayal.
After the Quorum meeting, Simas meets with Nautzera and discusses how they already know that the Fanim will be the true targets the Holy War. They lied to Achamian because they feel that he is weak and needed the motivation. During a private conversation, Nautzera expresses doubts about the strategy, but Simas assures him that it was necessary. Nautzera becomes annoyed by Simas's mild personalty, believing that it is an act.
At some unknown point, Simas is killed and replaced by a skin-spy. Its identity is exposed by Maithanet during a visit to Atyersus. The skin-spy who impersonates him is the only skin-spy ever known to be capable of sorcery.