Armand Bouchart's agent

The unnamed agent employed by Armand Bouchart, Grand Master of the Templar Order, was Bouchart's best man and a covert agent that specialized in espionage and assassination.

Biography
His mission was to infiltrate and sabotage the Cypriot resistance, which he achieved by killing Barnabas and impersonating him. Under this disguise, he misled Altaïr, whom he manipulated to kill Jonas, a popular merchant in Kyrenia.

Later, he met Altaïr again and killed an important person that the Assassin had intended to interrogate. It was only after seeing the severed head of the real Barnabas that Altair confirmed the true identity of the man he had met in Kyrenia: a Templar mercenary.

Finally, Armand Bouchart's agent killed Alexander, the leader of the resistance, and prepared a trap Altaïr near the entrance to the Templar Archive.

There, he revealed himself as the one posing as Barnabas, and had no doupt that he could and would kill Altaïr, partly in order to take the Apple from him. However, he ended up bein stabbed from behind by Maria Thorpe, even before the fight began.

Skills and Appearence
He was stealthy, an incredibly fast killer, and a spy who was able to easily escape from Altaïr Ibn-La'Ahad not only once, but twice. He wore his Order uniform most of the time, and usually hid his face. Altair was uneasy of his casual and almost eager attitude towards death, as seen when he laughingly stated the death of Jonas.

Trivia

 * Armand Bouchart's agent was the only major enemy that isn't killed by Altaïr, but by an ally instead, being Maria.
 * His true name remained unknown throughout Bloodlines.

Reference

 * Assassin's Creed: Bloodlines