Alfred, I caught sight of what looks like a heavily armed ninja. Looks like he's got some firearms, explosives, and he's wearing a stealth suit.

Solid Snake. He's called the legendary mercinary. Well, ever since the Shadow Moses Incident back in 2005. He was the biproduct of the (french accent) Les Infants Terribles (normal accent) project, cloned from the remains of the original Snake, now called Big Boss.

I figured out how he's doing it. He's got nano-machines inside his body that enhance and regulate his abilities. Pain reliever, anti-anxiety, PTSD control... Any scenario he can think of, he's got the thing he needs for it.