If co-op mode is enabled, Knight accompanies Bishop on missions, whose appearance also varies depending on how the player desires him/her to look. His/her role, however, is limited as merely a co-op player, and unlike some games, such as "Gears of War" and "Halo 3", Knight is not critical to the single player campaign's story, as elaborated on the Eurogamer review. Playing as Knight also allows the player to unlock co-op achievements.