Definitely an interesting prequel. The idea surprised me at first (mainly because I'm so used to Kishi's canon and after not reading anything of yours for a while it was kind of strange to get into the "not post timeskip" mindset of Teamwork\)... but I really do like it. (wow i'm rambly). I also liked the "my dear" at the beinning, it's just so Orochimaru. Itachi's emotions, analysis, and actions based on the situation are entirely appropriate. I like how much he manipulates Sasuke, even in a way such as this. And his indignation at getting injured is so appropriate. Sugietsu's cameo was a nice touch... and I love your description of Kisame.

~Sara