Decent Idea
You made a good choice by using the Japanese voices - I've personally only watched the series in dubbed format.
A few hitches, though: First off, the background was from Naruto - if you could somehow find a more "fitting" background, even be it woodland, it would help out the flash some.
Your sprite movements weren't smooth - Even if they are flash stepping it might be a good idea to find a vertical line fade out/in type so you know what is going on. Else it just looks like they are popping around the screen. A better "blood" decal/effect is also something you might want to consider.
All-in-all, a good idea and a nice attempt at executing it. Just work on finding some sprites to fill in jumpy/instant movements and clean it up a bit and you'll have a relatively nice flash submission.
Good luck to ya!