Marvin Mobuto

"I didn't know you, Sarge, but I sure as hell wish I had. You must have been one hard-core son of a bitch."

- SPARTAN-117, upon finding Mobuto's body

Staff Sergeant Marvin Mobuto was a UNSC Marine non-commissioned officer and the first Reclaimer during the Flood infestation on Installation 04.

Biography
Staff Sergeant Mobuto participated in the Battle of Reach, and was on the Pillar of Autumn when it made a blind jump to escape from Reach. Since the Pillar of Autumn traveled directly from Reach to Halo, it can be assumed Mobuto was involved in the battle itself. However, his involvement during the conflict is unclear and unaccounted for. He participated in the defense of the Autumn and was evacuated before the craft crash landed onto the Halo.

A Reclaimer
While on the ring, Mobuto was somehow detached from his squad and was contacted by 343 Guilty Spark, who used Halo's teleportation grid to transport him to the Library, much like he did with the Master Chief. Instructed to retrieve the Index, Mobuto fought valiantly through hordes of Flood, Combat Forms, Carrier Forms, and Infection Forms. With little experience against the enemy and standard, UNSC-issued ballistic body armor as protection (which 343 Guilty Spark referred to as "Insufficient armor,"), Mobuto eventually succumbed to the Flood's might. His body was completely thrashed and mangled to the point where the Flood Infection Forms could not make use of his body. It is suggested he could be a SPARTAN I due to the great battle (seeing as the Master Chief, even with his MJOLNIR armor and energy shields, could barely make it that far) he must have fought against countless Flood numbers.

Master Chief found Mobuto's body in the Library during his mission to collect the Index. John discovered Mobuto's identity through his dog tag and paid his respects to the Marine. Master Chief was surprised at how far Mobuto had managed to get, as he himself had been pushed to the limit to get as far as he had even with his augmentations and MJOLNIR body armor. Mobuto's determination inspired the Spartan to continue through the Flood-infested halls and complete his mission.

Trivia

 * It is unknown exactly where Mobuto's body is in the complex in-game.