XOF

XOF was the covert support team of FOX that eventually became the personal strike-force for Cipher and Skull Face in Metal Gear Solid V, making them the main antagonists of those two games.

History
XOF was formed in the 1960's by Major Zero and Skull Face to serve as FOX's covert support unit. Its existence was so secretive not even The Boss herself knew of it. After Zero abandoned FOX for Cipher, XOF became Cipher's elite strike-force. Skull Face eventually betrayed and usurped Zero, taking full control of XOF and using it to utterly destroy Militaires Sans Frontières in a complex revenge scheme. Nearly a decade later, the MSF's corpse came back as the Diamond Dogs who waged war on XOF and eventually won, killing Skull Face and causing its operatives to scatter.

Members

 * Major Zero (founder)
 * Skull Face (commander and co-founder)
 * Quiet (former assassin)
 * Tretji Rebenok (former psychic)
 * The Man on Fire (heavy support)
 * Emmerich (former engineer)
 * Parasite Unit (heavy support)
 * Dozens of soldiers, composed of American Vietnam veterans and ex-Special Forces