Giving a weapon the Shuriken animation

I'll say up front, I haven't done that edit personally, but normally issues such as that are caused because the game has one set of pointers for items, then a whole other table/list for graphics. In other words, one adress is being changed, the other is still set to default. Did you edit any hex? Probably an issue in C2, maybe even C1.

Also a slim possibilty that the type of item is still being read as knife, instead of graphic spell. I've read something on it but don't recall exactly, or if it said how.

Have you, or are you using, Draken's MDE? It might help if you haven't tried it yet.

Might be something useful on the thread where they added a crossbow and arrows to the game. Might search for it, google FF6hacking crossbow it'll show.

Sorry can't be of more use.