FNAF 1 GT: You are the killer and this is nightmares before death row
FNAF 2 GT: Phone guy is the killer and somehow kept his job
Fnaf 3 GT (Probably): The guy in the suit isn’t actually the killer but a child who didn’t actually die and grew in the suit until he died. And you are the killer, returned after 40 years.

mattpat actually doubled down on phone guy being the killer in fnaf 3 stating that he’s the only one who knew about the safe rooms and spring suits in the timeframe, sidestepping phone guy’s obvious death caught on tape, and his own new discovery that the tapes are ancient. What’s more, the killer was caught on video and captured with a solid date no less, something he’s yet to address in any video, and blows every theory wide open.

With purple guy being explicitly shown to be inside the spring bonnie suit, and the killer in the article being described as only having two victims before being immediately captured and later convicted, that means there is another killer that’s been completely unaccounted for, who definitely is in prison unless he escaped.