Six

Lieutenant SPARTAN-B312 was a Spartan-III supersoldier attached to Special Warfare Group Three of the UNSC Army. During the Fall of Reach in summer 2552, B312 served as a member of NOBLE Team under the call sign "Noble Six". Although unknown to most of the UNSC military and humanity in general due to the classified nature of their operations, Dr. Catherine Halsey stated that B312 shared a "hyper-lethal" rating with only one other Spartan and served just as essential a role in securing humanity's victory in the Human-Covenant War.

Since his file was heavily redacted by the Office of Naval Intelligence, much of SPARTAN-B312's early life is unknown. The Spartan was originally a Beta Company candidate whose performance so impressed his superiors that B312 (along with a small number of their peers, designated "cat 2") was reassigned immediately after training before the inevitable bloodbath of Operation: TORPEDO. As one of the few remaining contemporary Spartan-IIIs, B312 was repurposed as a counter-terrorist operator, performing black operations. After several years of being fielded against Insurrectionists, B312 was transferred from his ONI handlers to Spartan NOBLE Team, where B312 took the deceased Thom-A293's place as "Noble Six". B312's transfer to NOBLE came immediately at the start of the Fall of Reach, placing the Spartan in a new territory of teamwork against the Covenant.

SPARTAN-B312 was regarded as a skilled assassin and "... more of a hyper-lethal vector than a soldier," evidenced by his heavily redacted personnel file. Noble Six had a tendency to "go solo" during missions, much to the dismay of his superiors. Despite having an obscure past, highly potent skills, and a reserved, "lone wolf" personality, B312 showed care and compassion for his fellow humans; the Spartan often undertook life-threatening actions to assist soldiers, civilians, and the other members of NOBLE Team. Although Six became fairly close to the other members of NOBLE Team, he shared a great deal of camaraderie with Jorge, and the two soon became friends. He uses a MA37 and M6G.

Noble team members: Noble One - Carter, Noble Two - Kat, Noble Three - Jun, Noble Four - Emile, Noble Five - Jorge, Noble Six - Six

The SPARTAN-III program was a secret project initiated by the Beta-5 Division of the Office of Naval Intelligence's Section-III in order to produce cheap and expendable super soldiers to fight for the survival of humanity and the United Nations Space Command's colonies. The SPARTAN-III program was both the successor and supplement to the SPARTAN-II program. Created and engineered by Colonel James Ackerson of the Office of Naval Intelligence, the SPARTAN-III soldiers were to be the next generation of supersoldiers. Composed primarily of vengeful orphans from fallen colonies, they would be cheaper to arm, train, and produce; being chosen from a wider pool of candidates, they would also be more numerous than their SPARTAN-II predecessors. They would rely on superior battle tactics, and teamwork rather than advanced technology and equipment to achieve their combat effectiveness.

Reach is a human colony world in the Epsilon Eridani system, located within the Inner colonies. The UH-144 Falcon is a troop transport tilt-and-transverse-rotor helicopter in primary use by the UNSC Army.

The Charon-class light frigate is a type of escort ship manufactured by SinoViet Heavy Machinery and formerly in service with the CMA Navy and UNSC Navy. Ships of this class are used primarily in fleet escort duties, planetary defense, and the landing & deployment of mobile troops. The Paris-class heavy frigate is a classification of fleet escort ship in service with the UNSC Navy.

The Sh'wada-pattern supercarrier , is a powerful supermassive capital ship and one of the largest vessel classes formerly used by the Covenant, primarily designed for command and control duties for fleets, as well as support for occupation forces. Ket-pattern battlecruiser is an intermediary warship. It is frequently used, surpassing all other Covenant vessels numerically.

The MA37 assault rifle is a standard-issue automatic rifle utilized widely by the United Nations Space Command.

The M6G Personal Defense Weapon System (PDWS) or magnum, is a handgun in Misriah Armory's M6 series.

The M392 Designated Marksman Rifle (DMR), formally Designated Marksman Rifle, Caliber 7.62mm, M392, is a gas-operated bullpup rifle used by the United Nations Space Command.

The United Nations Space Command (UNSC) is the military, exploratory, and scientific agency of the Unified Earth Government (UEG) and has acted as the emergency governing body of the human race.

The Covenant is a massive religious hegemony of multiple alien species that completely controlled a large portion of the Orion Arm in the Milky Way Galaxy for thousands of years. The Type-25 plasma rifle, used by Convenant infantry, is a battery-powered directed-energy weapon that is capable of fully automatic fire. The Type-25 Directed Energy Pistol, the plasma pistol, is a Covenant infantry weapon

The Sangheili, or "Elites" as they are known by humans, served as the military leaders of the Covenant. The Sangheili are the only race within the Covenant permitted to build and command starships within the Covenant, though the crews are always composed of a mix of races. The Jiralhanae, or "Brutes" as they are known by humans, were the most recent addition to the Covenant, and served as soldiers and bodyguards within the Covenant military. The Lekgolo are a race of worm-like creatures that can combine to form large, intelligent assemblages called Mgalekgolo, known by humans as "Hunters". Clad in nearly impenetrable armor and armed with their trademark Assault Cannon, they served as the Covenant's heaviest ground troops. Hailing from Balaho, the Unggoy, or "Grunts" as they are known by humans, were the most common and low-ranking caste of the Covenant. They breathe methane gas, and thus must wear a large tank on their back full of methane to survive on other planets. The Kig-Yar, or "Jackals" or "Skirmishers" as they are known by humans, were the scouts and marksmen of the Covenant military due to their superior senses.

The Human-Covenant War was instigated by the High Prophets of the Covenant following a discovery which led them to believe that humans were directly related to the Forerunners, contradicting their ancient religion. Seeking to keep various political and religious orders intact, the High Prophets declared a holy war of genocide against the human species, and the discovery of their relation to the Forerunners was kept a secret. With superior firepower, numbers and technology, the Covenant would repeatedly overpower the UNSC across hundreds of human-inhabited worlds, including the heavily defended strongholds of Reach and Earth. Humanity would win only scattered and costly victories.