Altaïr’s mentor and the main antagonist in the first Assassin’s Creed is Al Mualim.
Al Mualim leads the Assassin bureau at Masyaf and serves as Altaïr Ibn-La’Ahad’s teacher. After Altaïr’s failed mission at the beginning of the game, Al Mualim reduces his rank and sends him to eliminate targets across the Holy Land.
The missions eventually reveal that Al Mualim has his own ambitions and has been manipulating events. His role changes from trusted mentor to central opponent as the story approaches its conclusion.
The name “Al Mualim” is an honorific meaning “the teacher” or “the instructor.” The character is loosely associated with Rashid ad-Din Sinan, a historical leader of the Nizari Ismailis, but the game’s version is fictionalized.