Noble 6
SPARTAN-B312 was a SPARTAN-III commando of the UNSC Naval Special Warfare Command, attached to Special Warfare Group Three. B312 served during the Fall of Reach as a member of Noble Team under the call sign "Noble Six"
SPARTAN-B312 was taken out of Beta Company immediately after training, according to a communiqué from Kurt Ambrose to Franklin Mendez that was sent in May 2545, two months before Operation: TORPEDO.
Over the course of B312's career, the SPARTAN gained a reputation as an efficient lone-wolf assassin, having single-handedly broken organizations and made entire militia groups disappear. B312 was also a test pilot in a top-secret UNSC project, the Sabre Program, which resulted in the development of the YSS-1000 "Sabre"-class starfighter. B312 used these skills to great effect in a counter-insurgency operation on Mamore on May 10, 2552.
At one point, B312's superior allegedly used the SPARTAN as "his own private grim reaper", and because of this, he was reluctant to have the Spartan assigned to Noble Team. On July 24, 2552, SPARTAN-B312 was assigned to Noble Team as a replacement for its previous sixth member, Thom-293. Six, having recently arrived on Reach, joined the team just in time to participate in an operation to investigate a communications blackout at the Visegrád Relay, a mission which led to the first confrontation with Covenant forces on Reach.
During the final weeks before Reach's eventual glassing, Noble Six partook in multiple operations against Covenant forces on Reach along with the rest of Noble Team, including a counter-offensive operation to retake an ONI base, a night-time reconnaissance mission with Jun-A266 (where the two Spartans forged a temporary alliance with some local militia), and a large-scale UNSC assault on a Covenant-occupied site and the neutralization of a Covenant tower.
With the Covenant successfully disabling Reach's defenses, and proceeding to glass the remainder of the planet, Six was among the last surviving UNSC soldiers left fighting the Covenant forces on the ground. Six continued fighting, and held off an entire army of Covenant single-handedly, including Wraith tanks and air support.
But the Covenant were relentless, and after countless hours of battle, an exhausted Six was eventually injured by plasma fire and after triumphantly taking on multiple Ultra and Zealot-class Sangheili in hand to hand combat, was finally overwhelmed, disarmed and forced to the ground. Here, though mortally wounded, Six subdued a further four attackers, succumbing to death amongst a pile of slain enemies, at the hands of an Energy Dagger wielded by a Zealot. Six's helmet remained on Reach, even after the planet was glassed by the Covenant and after the planet was terraformed.