This man - referred to only as The Commander - is the leader of the Guardian Units of Nations in the Sonic the Hedgehog game series. He makes his first appearance in Shadow the Hedgehog, leading the forces of GUN during the Black Arms invasion and answering only to the President of the United Federation. As well as coordinating GUN's troop movements, the Commander is also a capable pilot and rides the experimental Diablon mecha into battle against Shadow as one of three penultimate bosses.
The Commander also appears in the Archie Sonic the Hedgehog comics. The comics have given him a proper name: 'Abraham Tower'.