Is it based on the video-game? (Excuse me, that's more of a question than a review.) However, your story is interesting, there's nothing that's really bad. (My only problem, and this is a personal opinion...I usually lose interest when it's an anime sort of thing. No offense, I know you like anime. (read your profile ^_^) It's good so far, I'm sure others will like it.

Oh yeah, maybe you should change the title. Assassin's Creed is a video-game and some users may get confused. That's just an opinion as well, you don't have to!