This is my favorite DoD song! Love it! I often skip forward to this song because I can't wait to hear it. As far as the "why does this war song sound cheerful" complaint, I see it as the warriors trying to keep their spirits up high as they move on to a bloody war. 
this was one of my favourites of the past ten years, this needed to be in the tour setlist in place of something!!!! Apprently Nicko fought hard for it but Harris shot it down. Janick shows off his great songwriting skills on this one.