Sergeant major

In the UNSC Marine Corps, Sergeant Major is the ninth and highest enlisted rank, just above First Sergeant/Master Sergeant, and equal in pay grade to Master Gunnery Sergeant, although the two have different reponsibilities. A Marine Corps Sergeants Majors serve as the senior enlisted Marine in the Corps' units of battalion, regiment, or higher echelon, to assist the unit's commander and to handle matters of discipline and morale among the enlisted Marines.