From Halopedia, the Halo wiki
While Unggoy Storm were specialized shock units under the original Covenant, post-war Storm troops serve a more generalized infantry role similar to the Unggoy Minor. They are essentially cannon fodder for the various Covenant factions, with the Sangheili using the Storm Unggoy's large numbers to their advantage.
In a effort to increase field of view, the Unggoy Storm helmet includes a nose-placed rebreather somewhat resembling the diving apparatuses used on the Unggoy homeworld of Balaho. The harness has a pressurized methane tank, with a filter actuator to help keep the tank working. The harness also allows for the Unggoy to use the methane tank as a makeshift thruster pack, allowing for easy access in various terrains.
During the Battle of Requiem and the Requiem Campaign, Unggoy Storm of Jul 'Mdama's Covenant commonly fielded Type-25 plasma pistols and Type-33 Needlers. Occasionally they wielded the Type-33 fuel rod gun as an explosive weapon. During the Covenant's final days in October 2558, Unggoy Storm began to make heavy use of the Type-54D plasma pistol and Type-56D Needler. The Type-58 fuel rod cannon had since become the main explosive weapon for Unggoy Storm. During the Battle of Sunaion some shock troops made use of Type-57B carbines.
Storm Unggoy are armed with plasma pistols and Needlers, and will occasionally use an overcharged plasma pistol shot against shielded enemies. Like Minors, Storm Unggoy will very commonly flee from battle when the Sangheili leading them is killed. Storm Unggoy will sometimes prime two plasma grenades and charge their enemies in a kamikaze attack.
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