https://www.pcgamer.com/metal-gear-solid-5-update-makes-quiet-playable-in-fob-missions/

An unexpected update to Metal Gear Solid 5 enables players to take on FOB missions as Quiet, the steady-handed sniper who wears a skimpy bikini into battle not for reasons of jiggly titillation, but because she breathes through her skin. 

Quiet is a master sniper who can take long shots with minimal shake, and she also moves very quickly and can jump over objects that other characters would require a ladder to traverse. Standing still "will make her stealthy," and she has a dash ability that enables her to close and engage with enemies very quickly.