Primate Artorius

Primate Artorius Ponticus is the leader of the Akatosh-revering Order of the Hour situated in Kvatch. With The Black Dragon, he serves as a main antagonist against the Dark Brotherhood, systematically killing off the group's members.

A Ghost from the Past
With the fumes of Green-Venom-Tongue's resin, apparitions of Artorius and Lyra Viria's from the past are seen, depicting Lyra's transformation into the Black Dragon:

Primate Artorius: "Put away your weapon, child. We have much to discuss. You feel lost, without purpose. But the opposite is true. Everything has led you to me."

Lyra Viria: "Oh really? I just see another witness that needs to be silenced."

Artorius: "I performed the Sacrament that brought you here. Not because Primate Jonas needed to die, but because the Dragon God wanted us to join forces."

Lyra: "Join forces? I don't understand..."

Artorius: "You need to turn away from the Void and step into the light. Join me and together we'll walk the path to redemption."

Lyra: "Redemption? I'm a murderer! There's no redemption for someone like me."

Artorius: "Nonsense, child. Akatosh performs more impressive miracles than that all the time. We just need to turn your talents to the holy work of the Dragon God. Become my champion, a sword of Akatosh―my Black Dragon that burns away evil's darkness."

Lyra: "I... yes. I see it now. I pledge my blade and my life to you and to Akatosh. Show me the way."

Following this, their visions shall disappear.

Filling the Void
After infiltrating the catacombs and entering the cathedral, Artorius will be at the very back, near the stained glass of Akatosh. When you are spotted, he will initiate the following conversation:

Primate Artorius: "And so, the assassins finally arrive."

Astara Caerellius: "Time to die, Artorius."

Artorius: "Time? Time is my domain, murderer, not yours."

Once Artorius is defeated, he will neal towards the stained glass. Astara commands you to finish him off, to which you pick up his staff and impale him.

Combat
During Combat, Artorius has a very unique advantage in that he can stop time at will by freezing his minions and dark brotherhood members in place at will. When you are frozen, you must use crowd control to break free and attack him. The periods of time freezing are the only times in which Artorius can be done damage and the only time he moves around the cathedral. The periods of frozen time only last for about 20 seconds, after which he will return to the podium. Once all of Artorius' health is depleted, he will be kneeling in defeat at the stained glass of Akatosh, in which you must then activate his staff and impale him.

Trivia

 * Primate Artorius was the subject of a Loremaster's Archive in May 15, 2015, a year prior to the release of . However, he was originally known as a bishop instead of a primate in the archive. It can be assumed his title changed some point during development.