The Greymen was a closed circle of nine businessmen and important people from various sectors of the economy of the post-Ulysses Disaster world.
The group was created following the Ulysses Disaster, possibly to assist in consolidating recovery efforts around the world. However, with living conditions worsening in areas such as Iyuli, many questioned the Greymen's ability to actually help.
In May 2019, all nine Greymen were kidnapped by the Sons of Troia, a terrorist organization working in the Iyuli region. The United Nations Forces immediately began Operation Fogbound to rescue them, utilizing their Ridgeback Squadron and Marine commandos as well as, under contract, Bone Arrow Squadron. The UNF's intel led them to believe that the Greymen were being held in a facility in Iyuli. However, the commando teams discovered the Greymen were not inside. Shortly after, all forces were ambushed by Stonehenge Type-3 and forced to retreat.
- Some of the Greymen resemble characters from Ace Combat: Assault Horizon, including Pierre La Pointe (top row, second), José Gutierrez (top row, third) and Andrei Markov (bottom row, last).
- One of the Greymen (top row, first) resembles Jack Tretton, former President and CEO of Sony Computer Entertainment of America.