I was just going to review the film but I may as well cover everything, this is Clamp's X.

The world is coming to an end and Kamui arrives into Tokyo as the one prophecy that will decide the fate of humanity and to which side he favours, the Dragons of Heaven or the Dragons of Earth, but he sides with the Dragons of Heaven as their outcome sides with Humanity and he likes his friends alive; not happy that Kamui has chosen their enemy, the Dragons of Earth create their own Kamui in Kamui's best friend Fuuma by baiting him with his sister Kotori. Fuuma's personality change sets the scene for the final battle as both factions go all out to decide how Armageddon plays out and all the angsty melodrama that goes with it.
I admit the animation is something to behold especially in the movie where the visuals are right up there with Akira but the story and characters are crap, made worst by the movie because no one is on screen long enough to make an impact because they die as quickly as Yamcha against a Saibaman.
The endings are pretty pointless as the story has been on hiatus for 16 years as of today with no plans to continue.
Then we come to Kamui, the best way to describe him is an early 2000s pretty boy with problems protagonist created by a yaoi fangirl who learned all her angsty writing from Twilight, he does nothing but burst into tears instead of I don't know actually using his powers to actually save someone and is only really there to be thrown into homo-erotic fanficton of himself being a play thing to every other male character from the series, now this is not me having a problem with Yaoi, in fact I criticised Fake for not having enough but if I had to watch the whole series with Kamui as a lead I'd lose my mind. I think Kira Yamato put it best in Gundam Seed, "what can you protect if feelings are the only weapons you have?" Clamp built a scenario with grand set pieces and enough creative freedom to go crazy and it completely wastes it on the wrong protagonist, this is why you are artists, not writers Clamp, you can make grand worlds with your beautiful art but all your stories are total and utter trash.
Dubs aren't really any better, the movie especially lacks decent acting as many under sell their performance.
I need pain killers after that.
Final Verdict: Setup like a grand master piece, performed by someone who thinks Twilight is literature.