Savage Cyan who is close to death managed to escape. He took the Withered Toys with him, with his condition he walked for months, which leads to 2038. When he finally finds the bodies of his old friends, he wants his friends back. He goes to the first Cyan's Hero Pizza Palace from 2025, which was abandoned and in bad condition. The cloning machines were there, with there, with the bodies of old friends and their spirts following him, he had plan. Using the bodies along with the machines, he manages to change their code with the help of Cube, creates new bodies which is how the Nightmare clones were born. He builds with part of the Toy animatronic The Toymare. A hybrid made form Toy Cyan, Toy Drac, Toy Katya and Cubgle (or Toy Cube), who he probably took his (her*) parts by going to the second Cyan's Hero Pizza Palace from 2027. If you don't see where there is a part from Toy Drac, this here is his lower body. Cyan with his Nightmare pals and The Toymare head out away from the place, to hopefully find a new area to restart and make everyone better for themselves. He found a paper from a phone book. Four Guardians, who was presumed dead is still here around. Cyan realises that Four Guardians, who also knew about the clones could easily get authorities after the clones if he sees them again. The light blue square, wanting his friends to be safe, didn't want that. He doesn't know where he is, he's actually hiding in first Cyan's Hero Pizza Palace where Cyan just went who realises that. So tells his friends to the place as soon as possible with The Toymare, to kill him.
Just a note about the office in FNaC4: we can now see a pirate cove behind us. You'll say it also presents in FNaC1 since we can't see behind us. But I'll say no to that, in the cutscenes of FNaC5 where we see each game office in point of view of each respective Golden Cyan, the FNaC4 one has of course the pirate cove, but in the FNaC1, there's no cove! So my opinion is, it's possible it could be an unused cove or Cube's cove which has been moved here after at least the events of FNaC1, after all, it has been shut down as mentioned the FNaC4 extras, like an unused prop. I say it's possible because we can only see the office and the halls in the restaurant during FNaC4. Anyway. Soon after Salvage Cyan told his friends to go, he comes across Golden Cyan (or Blixer). Half of his body has completely melted, called "Nightmare Golden Cyan" in the game. Who stab him as a payback, as revenge. The events between Salvage Cyan finding his friends once again and Nightmare Golden Cyan Killing him Happened in 5 days, which were before night 1. The 1st day, he finds his friends. Next day, he arrived at the restaurant from FNaC1, in front of the cloning machines. Next one, he has the Toy animatronics' parts with him, and is about to build the Toymare. Day four, outside again, with the phone paper with him, looking for Four Guardians. Final day. He came across Golden (or Blixer), who kills him. So after, to make sure to finish him off, Golden takes his body and stuff it in his own creative, The Toymare. When he was at the restaurant, where the Nightmare went, who saw him stuffing Cyan, they did what Cyan did. Using his spirit, which we can see as an easter egg in the game and who's here to haunt Four Guardians since he wanted to get him. To create Nightmare Cyan, who gave him a phone call before sending his after them.
Nightmare Cyan "6 days"
Golden Cyan attacks Four Guardians too. So that right we're playing Four Guardians in FNaC4, lots of people thought they was dead in FNaC1, and became of FNaC2 being a sequel they thought they was the Fourinette. That would have been so SCARY. They survived the week and escapes after, Nightmare Cyan and the others are pretty mad about it and find his helmets. Four Guardians reports the clones to the authorities, they send them far front civilization, and destroy The Toymare completely. Golden Cyan is once again hiding to not be sent too. Yeah... The poor clone Cyan, who was made to entertain people, ended up by not excited anymore. All of this tragedy was because of Blixer, who is still haunting Golden Cyan. Who were also supposed to be a Cyan clone, just to... entertain people... He's still here, and has become Shadow Cyan. The cloning material has melted and covered all of his body.