The Faded is a new gameplay modification for Natural Selection 2 based on The Hidden: Source.
In The Faded you have the Marine team and the Fade. The Fade escaped the research facility of TSA where they made experiments with it. Unfortunately those experiments gave the Fade permanent upgrades which make him the perfect killer: fast (Celerity), stronger (Carapace and Adrenalin), silent, invisible (Cloak) and enhanced abilities (Shadowstep, Blink, Vortex). The Marines need to kill the Fade within a given time, otherwise they loose and the Fade will escape. The Fade will be chosen randomly among all players, that's why you are only allowed to join the Marines team.
It's not done yet. If it is done, just type in 'faded' as game in your Natural Selection 2 server browser and if there are any servers which run The Faded you should see them.