Though seen multiple times in Fort Delta the mysterious 13th special forces is one of the most secretive special forces on Kepler 22b. The 13th has been used in the past to replace Spartans due to there experience in stealth. They have been spotted almost always disappearing seconds later. They have been used most recently in the civil war raging on Kepler 22b to counter the terrorists. It is most likely that the regiment was formed after the invasion but its likely this regiment is based from the UNSC, yet the regiment works on its own as there are few military files on them.