Exo-Force was a theme inspired by stories from Japanese manga and anime such as Mobile Suit Gundam and Robotech. The theme and its sets were based around enormous combat mechs known as battle machines piloted by humans against the robots, consisting of the Devastators, Iron Drones and their leader Meca One, who themselves possess combat machinery of their own, with the intent of complete dominance of the mountain they live on, Sentai Mountain. What lay at the bottom of the mountain was never revealed. The theme lasted two and a half years, as it was introduced in spring 2006 and later discontinued in the summer of 2008. The working title for the series was Battlepeak. There was a book series based off of the sets.