Metal Gear lives in a world between realistic world and fantasy. Characters like Snake, Otacon, and many other characters follow law of the real world. Then there are characters that have super powers from Nano machines, parasites, or …. just because.
Character like Vamp, FROG soldiers, and Screaming Mantis has stated that their powers come from nano machines. Nano machines and small robots inside people’s body increasing their performances.
Most of the super powers from MGSV: Phantom Pain comes from parasites. Quiet and many other characters have them. They are like pre-MGS1 nano machines.
And there are characters whose powers’ origins are not discussed. Because there is no reason to. The End can use photosynthesis because he can.
Psycho Mantis can use telekinesis and read people’s mind because he can.
Volgin has shoot electricity from his body because he can.
The Sorrow’s ghost comes from the afterlife to guide Naked Snake, becaus of regret…..?
Not everything needs explanations, and I have no problem with that. I hope you enjoyed this!