This unnamed man was a hunter.
In Who We Are, he is one of the hunters called to Jody Mills' house by Sam Winchester for help attacking the British Men of Letters. Along with all of the other hunters present, he agrees to join the attack.
During the attack on the British Men of Letters compound, one of the guards opens fire with a machine gun, severely damaging one of the hunters trucks and killing this hunter. His death is avenged moments later when the guard is shot by the unnamed female hunter.