The issue there is that at the end of that fic Itachi and Sasuke go their separate ways with the understanding that Sasuke will still go after Itachi to kill him at some point. And by that point he's already controlling his nekomata powers okayish, and then he ends up back in Konoha, and so the sequel would start in a place/mood/emotional resonance that has nothing to do with the first fic anymore. ^^;