It sounds very good and has some strong provokative vocals, but I am not entirely sure what it means, the images have very little to do with Halo and I can't really tell if it's pro the game or not or if it's trying to make some kind of message.
Still, I did like the line:
"You are the Halo."
Because for some reason I can't help but feel there is poetry in that line in particular, even if I am not entirely sure what that is.