Long, confusing, and excellent.
This is the first episode of this series that I have seen - probably not a great way to start, considering that this is the final one. I often found the story and what was happening rather confusing, but I'll chalk that up to not watching the previous episodes and not downgrade you for it.
The sheer scope of this flash, however, is amazing. This thing is LONG. And I mean REALLY LONG - I thought it was going to end several times, but it just kept on going. It is also very well animated and choreagraphed.
I'll admit that your animation style isn't one of my favourites (it's a bit too angular for my liking), but you do an EXCELLENT job of animating your characters with a minimum number of frames in just the right places. I was very impressed by the graphics - the style, the colours, and how well you animated the fight scenes, camera pans, and all manner of other effects.
The music was also appropriately chosen. The one thing that brought this flash down was the quality of the voice-acting. The script isn't bad (although as a previous reviewer pointed out, the grammar is sketchy in places), but the delivery is cringe-worthy. If I were you I would've found people who could actually act somewhat well to record the voices. I could see that the voice-actors were trying to be good, but the majority of the time it ended up sounding unnatural and forced.
You should really consider a career in either directing or animation, because this flash was great. A tip for next time would be to maybe choose a more straightforward and easier-to-understand story line. I didn't mark you down for that, but I did have a (perhaps inaccurate) impression that this story might've been a little too complicated for its own good.