Darius Slade would be an old friend of Henry and William who would help in the creation of Animatronics, and this are the creator of Nightmares, Rat and UnWithered Cat and even Vinnie, that would have been proposed but declined

Some time later he would have joined the army, and then been sent away for being a general obsessed with victory.

He would seek to show what he is capable of and create an invincible weapon for the army squad.

He would go to Sister Location, which was not difficult to access due to his closeness with William Afton, he would look for the projects there to create a robot for his use and discover William new projects with agony element

But, unlike a normal reaction of denouncing him for causing deaths, he likes his idea and tries to replicate his projects.

He would create a non-functional project that would try to copy the Funtime Freddy model, which would later become the Molten Freddy costume.

Then his restaurant would be created to attract people for testing, he would kill souls that would become Chester, Penguin and Old Candy, but they did not obey him.

So he had the idea of using Candy and Cindy with the souls of their children, who were always obedient, and could manipulate the rest of the group.

Candy was possessed conventionally, killed manually and the agony trapped him in the candy

Cindy was quickly possessed in a similar way to Baby.

And Darius would send the security guard to test what happens to an adult soul in the Animatronics, So he would send the animatronics to find him and without success he disguises himself as The Rat so that if it doesn't work he won't know his identity, and tries to kill the security guard to possess The Rat himself.

This is basically the story of FNaC 1 and a little before everything

Fnac 3 would be trauma after 1 and fnac 2 something similar to the original sequence of them returning to the factory