Molded by his creed
Just like everything else about Altair, his backstory wasn’t all too complicated. His introduction into the Brotherhood didn’t originate from tragedy or necessity, but he was simply born into this cult. It wasn’t until he betrayed his corrupted mentor, Al Mualim, that his story grew infinitely more complex, with his actions shaping the future of the Assassins that followed him. He even went as far as to become lovers with a sworn enemy, a Templar by the name of Maria Thorpe.
Edward Kenway’s cockiness or Jacob Frye’s nonchalant flare are written into the character and don’t change too much throughout the course of the corresponding games, but Altair’s stubborn nature and arrogance developed and were shaped by the path he took. He is by no means a likable character, mind you, but he’s rather a person who sacrificed everything to ensure a future for his Brotherhood.
Dying peacefully in his tomb at the age of 92, Altair frequently regrets some of the actions he had to undertake or the choices he was forced to make. Regardless of how he feels about his past, he wouldn’t change it in a heartbeat, knowing his connection to the modern-day Assassins as well as the First Civilization would save Earth from a terrible fate. Initially, many will see a man that is stubborn and impulsive, but those who have stuck with the series and have seen glimpses of him know how he has suffered for his people.