Phoenix Logs/UNSC Units/Green Machine
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Lean, mean, killing machine.
When Sergeant Johnson joined the Corps they didn't have any fancy-schmanzy power armor, but he's a quick learner. He drops onto the Ark in the "Green Machine," a bipedal weapon system custom-fitted with an array of miniguns, phased-plasma fusils, sonic blindwolf repellers, repair beacon pods, and fast-regen energy shields. He keeps a sharp stick handy as a backup weapon. The energy shielding rapidly regenerates after it hasn't been hit for a few seconds, which plays well with Sergeant Johnson's preferred tactics of hit-and-run raids and well-timed combined-arms strikes. The suit's repair beacon ability heals up to ten nearby allies with constructor beams tuned to a pleasing Marine Corps-approved green color.
The suit can be upgraded in the field, further enhancing the Green Machine's killing power. The Gauss Chaingun upgrade upgrade adds specialized high-power ammunition while the Beacon Shield pairs the repair beacon with a bubble shield, reducing incoming damage for those inside the repair radius. And last—but certainly not least—the suit can be upgraded with a Smart Missile pod for dealing with pesky nuisances at long range. Why doesn't he wear a helmet? Well, would YOU hide behind an armored faceplate if you had Sergeant Johnson's rugged good looks?