I can't even begin to comprehend the amount of work that went into this. >__>
It's stunningly beautiful. The composition of each scene, from the mask to the background scene selection to the colouring then the additional glow and particle effects, just wow.
It really brings out the story in the video, just gorgeous.
Also looking at your making of picture....did you animate 2 of the scenes in the AMV from scratch yourself? If so, you did an excellent job.
When I first saw the AMV (without looking at the making of picture) I knew you did a lot of composing for the heads/bodies with the one I could recognize the most easily being the kimono from Kara no Kyoukai but after a while I was convinced some were from the show and was like "....since when did Ao no Exorcist have these scenes?!"
Very impressive technical work indeed.
Only minor complaint I have, like others have already mentioned is the mood. Sometimes it's there but sometimes it isn't, so it kinda felt like it was flickering back and forward at a few points. But since it's not really a major issue I wouldn't take this to heart too much. XD Anyway the AMV was beautiful. I really enjoyed it.