First off, if you aren't watching True Detective then there is something wrong with you. The series is treated with the utmost care and depth that echoes great shows like Breaking Bad and The Wire. Not often do you come across such intelligent and powerful storytelling that you actually realize that the show is smarter than you are.
And thus with a show so steeped in its own mythology, theories have spun forth uncontrollably about who the series villain, The Yellow King, truly is. Tons of theories have pinned Marty, Rust, Governor Tuttle, Reggie Ledoux, even the Lawnmower guy that keeps the grounds of the closed school. The problem with nailing down who exactly to suspect is that the show has departed from every facet of conventional story telling for a more grounded and realistic take on the occult. It would be easy to say that we haven't seen The Yellow King yet, but it would be like True Detective to say we actually already have.
Digging through theories I came across The Four Horsemen Theory. The basic idea behind it is that instead of just one main baddy, we may actually have five men involved in this deep conspiracy. Even for those with a keen eye for detail would probably have missed these signs but that's what makes True Detective so special. The clues have been right under our noses.
