I thought the guy who killed sef blamed it on Malik (MASSIVE SPOILERS) and locked him him up Altair saved him and nursed him back to health but sadly the guy who killed sef sneaked in a decapitated Malik he then showed it to both Altair and Maria (NOT Ezio's mother)
I know it's not Ezio's mom lol and well it has been forever since I last played but according to my research it says (SPOILERS!!!) that Abbas told his apprentice/spy, Swami to stab Sef to death so that he could take control of the Order for himself. In the moments just before killing him, Swami told Sef that it was his father Altair who ordered the execution.
(SPOILERS!!!) After killing Sef the murder weapon was placed in Malik's bed and had on elf his spies say that he had overheard Sef and Malik arguing over who would regain control when Altair returned. Long story short Malik was framed for Sef's death and thrown into prison in the dungeon's beneath Masyaf.
I think I know why his face changed.Remember in AC2 Lucy said Desmond can learn Ezio's ability by using the 'Blood System' which means Desmond's blood is in Ezio so that Desmond can learn Ezio's moves,also Desmond is aging at the same time.
That's my biggest complaint about the game. You can't just change the face recognition actor all the sudden. The first thing I thought as I got into the game was "Who's that? What do you mean that's Desmond, that can't be desmond! Why the hell did you change his face?
Altair and that beard drive me nuts <3 I love that older mature look, it's just.... hmmm.
As for Desmond's face, it went back to the first Assassin's Creed look, if slightly altered. They changed it with AC2 to make him look more like Ezio and stuck with it until Brotherhood. In ACR it looks like they mixed him the "Ezio" look and the original look from the first game... which looks a look more like Francisco Randez, which is not a bad thing at all <3
they look always diffenent. if you don't see it, your eyes are not open enough. just have closer views to them. and Alta´r in ACR has the same voice as ezio in II and brotherhood (at least in german version)