The Greatest Movie Ever Made (2001)

The U.S. Marines are a band of brothers, until one day there is a split in the union because of Cowles's dead sister. After Nevitt kills everyone in the barracks, three heroes join forces to stop him, only to realize that there are many other obstacles in the way. Will they be able to stop Nevitt's evil rampage? Or will Nevitt and his mattresses triumph and destroy the world?