Impressive from an artistic standpoint.
I guess I'm not as harsh as some of the other people on here are, but I'm also not a Flash expert so the only credibility I have is as your average Flash movie watcher. Thus, "eye candy" is something that intrigues me, though I truly appreciate beauty when I see it.
First of all, I'd like to say that artistically speaking, this is highly impressive. The character artwork and backdrops are stunning. The colors are vibrant and the textures have a soft, mellow feel to them. I can definitely appreciate your hard work there. Though a tiny gripe of mine is that the religious references were a bit overbearing. In the church there must be dozens of crosses in view, not to mention the ones hanging from the white-haired character's cloak. Just cut back a tad on all the religious images, because it felt a little forced. I'm an atheist, but I don't think churches even have that many crosses hung up.
I agree with what Lesbian-Waffles said about the "Z-effects," but I'm more of a drawing artist than an animator. However, to a non-animator (especially if they're anime fans) it wouldn't be too big a deal since it's fairly commonplace and widely accepted. The animation with the vector graphics (correct me if I'm wrong since, like I said, I'm not an animator), did seem to be a tad choppy at some points but worked for the most part. For example, the part with the girl swinging her sword was well done.
I don't have much to say about the music, but it seemed fitting to the overall calm and mysterious demeanor. It was a good choice.
My biggest complaint would be the assumed plot. Three heroes...some cryptic guy standing in a church...and then what? It sort of reminds me of your typical JRPG. I don't like to judge before there's a final product, but it does have a little bit of a generic vibe. However, I shall leave that bit alone until I see the plot for myself.
Overall, I was enamored by the flair it held. It felt very authentic and could pass for an intro. I'm giving you the full 10 because while it has its downsides, it's still entertaining and attractive to those who aren't fluent enough in Flash to nitpick. Though you should take into account what Lesbian-Waffles said, because they're the other end of the spectrum; they have the knowledge and wisdom to help you. You have a lot of potential, so make sure to use it!