In the MetalStorm: Online Campaign, you can chose to add a wingman to fight alongside you, in order to add some extra firepower to your squad. There are three wingmen you can choose, besides Vargas and Copperhead. These three are Quicksilver, who flies the F-12 Talon, and acts as the Agility wingman, Obsidian, who flies the T-18 Cyclone and acts as the Weapons wingman, and Cobalt, who flies the M-11 Raven, and acts as the Defense wingman. The wingmen do not speak at all when they are playing alongside you, nor do they participate in the events of the story. In addition to Legion pilots, the player may invite a Gamecenter friend to be a wingman. Like all Gamecenter-related options, this requires a Gamecenter sign-in.
In Survival Mode, you can invite a Gamecenter friend to help you. Unlike Campaign, this means you play in a Co-op mode. Once both planes are destroyed, both of you get the earnings.