Nersei Proyas is the Crown Prince of Conriya.
As a Conriyan, Proyas has a dark complexion. He is not tall, but has a noble, impressive bearing nonetheless. Female characters call him "the handsome prince".
What Came Before
Proyas was a student of Drusas Achamian in his youth. The two shared a close bond, and Achamian loved him, but Proyas turned away from Achamian after becoming a devout follower of Inrithism. Xinemus was his swordsmanship tutor.
The Darkness That Comes Before
Proyas is a devoted follower of Maithanet, and he is present beside Maithanet as the Shriah announces the target of the Holy War.
He recognizes Achamian when the Mandate sorcerer is crowd-surfed to Maithanet's side. He is outraged by the blasphemy in spite of his former devotion to Achamian. Afterwards, Maithanet brings him to witness the Tusk for the first time.
Proyas joins the Holy War as one of its Great Names. leading his contingent of Conriyans. Upon first meeting Ikurei Conphas, the two men develop an instant rivalry and hatred for each other.
Proyas marches with the Holy War leading his Conriyans. When Kellhus convinces Coithus Saubon to separate from the rest of the Holy War and take his Galeoth host to attack Gedea , Proyas angrily confronts Kellhus at Xinemus's fire. Onlookers are shocked by Proyas's disrespectful treatment of Kellhus. Before leaving in a huff, Proyas accuses Kellhus of dooming the Holy War.
The Thousandfold Thought
The Judging Eye
Proyas is King of Conriya and one of the Exalt-Generals of the Great Ordeal.
The Great Ordeal
He is deeply hurt and puzzled when Kellhus confesses he is not a true prophet but is just a mad man. While he is experiencing emotional turmoil from this revelation, Kellhus drugs both their wine with chanv and has brutal sex with Proyas.
Later he seeks out Coithus Saubon and in tears confesses the forced sodomy and shares Kellhus's confession. Proyas realizes his buggering may be a test as much for Saubon as for himself. Saubon convinces him that Kellhus is testing them but states they must continue to act even in they lose faith as Kellhus will lead them to victory at Golgotterath. 
After the explosion of the mountain, Kellhus comes to Proyas and takes him to a mountain top and explains the great and tragic victory that has polluted the land. Kellhus explains that Saubon is dead and as lone Exalt General Proyas must rally the remaining Ordeal host and go North. He charged him with keeping everyone away from the polluted land and he must cull the sick suffering from seeming radiation poisoning. Kellhus prepares him that he is the only one who can lead and make decisions that no Believer can saying "Something must eaten."