William Afton I

"Young, strong, virile; everything I could want in a body. Yes. I'll control what's left of you." - William Afton I

About
Founder of Afton Robotics, William Afton I possessed a competitive streak when it came to developing and building animatronics and robots. This nature led him to view any other establishment with non-Afton animatronics as competitors to be destroyed if they didn't buy his creations instead.

His designs and programming were highly advanced for the time but he was never quite able to achieve self-aware artificial intelligence in his robots until he discovered a substance called Remnant.

1976: Fredbear's Family Diner Sabotage
Upon hearing of the beloved animatronics in Fredbear's Family Diner, Afton encouraged the rival diner he worked with to try and buy them out so he could get his hands on them for reverse engineering. When the plan fell through, he hired a local teen, Sydney, to force the diner to close permanently in whatever way possible. Sydney did so by killing several children in the diner in a single day. While the rival diner was horrified, Afton celebrated the slaughter and immediately created a shell company to purchase Fredbear's.

Upon creating Fazbear Entertainment and setting up a few Freddy Fazbear's restaurants to sustain the company, Afton was able to get his hands on the schematics for Fredbear and Spring Bonnie, shipping the animatronics to a nearby restaurant for storage while he expanded his developments for new animatronics.

Remnant
For several years after, he made many successful advancements in hardware and software, but his dream of creating truly self aware artificial intelligence still eluded him. Rumors reached him of how there seemed to be spiritual awareness in Fredbear's Family Diner and in the two animatronics shipped to a Freddy's restaurant. Afton investigated and discovered a substance in the animatronics that he deemed to be remnants of the original inventor. While he couldn't find traces of the substance in Fredbear's, he felt satisfied enough to try and replicate the 'remnants' in his facility.

His initial attempts to artificially recreate Remnant ended in failure, so he took to trying to extract it and memories from technicians, resulting in many of them dying to the process. With each failure to digitize memories and Remnant, Afton learned more about the substance and its limits and sources. As his staff dwindled, he hired on less qualified people to fill the slots and provide him with test subjects, leading to his crossing paths with Lucian Enfuego in 1983.

1984: Enfuego Experiment
In 1983, Afton set his sights on Lucian, a newly hired intern, for his next attempt at extracting Remnant. Surprisingly, Lucian not only survived the experimentation of having Remnant removed and processed into digital format, but was also instrumental in discovering the conditions for gathering Remnant. Afton learned that his prior subjects failed due to older age causing Remnant to become inactive and unable to be harvested. Younger subjects were more inclined to have active Remnant along with those who were previously exposed to large amounts of Remnant, such as himself. Assisted by his daughter-in-law, Elizabeth Afton, William set about creating animatronics capable of harvesting Remnant from children and using Remnant-based software to control their movements.

Over the course of a year, he repeatedly experimented on Lucian to obtain more Remnant, copy his memories, and build an A.I. with him as the base. During these experiments, Afton hit upon the idea of transferring Remnant, the essence of a human soul and life, from one person to another, and asked himself if this would allow for a copy of a human life to be made. William began extracting Remnant from himself and injecting it into Lucian during further experiments, taunting the man with the promise of being controlled.

Death
In Feburary 1984, William was nearing the conclusion of the download process of Lucian's memories when he removed the restraints that held the younger man in place. Months of extracting Remnant from himself without allowing it to replenish or be restored had caused the older man's sanity to degrade. While this meant he no longer was thinking clearly, William's actions allowed Lucian to disconnect from the machinery that was both copying his personality and memories as well as transfuse William's Remnant to him.

Afton was then killed by the enraged Lucian, stabbed multiple times and left to bleed out in the underground facility.

Hauntings
Afton's actions created two separate 'ghosts' of himself; his Remnant in Lucian took root and grew until it essentially overwrote the younger man's soul, allowing Afton to be in control as he had suspected would happen. While the process was slow and done over several years, enough of him was transferred to Lucian that he was able to guide and assert his influence over the serial killer. This allowed Afton to, by proxy, commit the murders of the 5 Missing Children and the Butterfly Child in Freddy's Pizza in 1987 as part of his attempts to gather more Remnant research material. Lucian was caught, however, and executed several years later, allowing Afton to be freed and return to the pizzeria as a spirit. Afton continues to use Lucian's appearance both to hide his true identity as well as enrage the ghost children so he can feed on the negative energy from their anger and sorrow.

Because of Afton's activated Remnant, he also lingered as a ghost in the facility, fragmented and dormant until Springtrap, controlled by the ghost of Router, wandered into the facility on a hunt for Lucian's own ghost after the events of the FNAF3 Arc. Afton awoke from the influx of negative energy and the lingering traces of his other self on the springlock suit, and enacted a plan to take control of the Springtrap suit himself.

FFPS Hunt
Once in control of Springtrap, Afton had the facility create a copy of the suit and picked up a message being sent to the facility from the old Freddy's Pizza location. Intrigued, Afton left the facility and followed the message to the pizzeria, finding it built up into a new restaurant run by Meera Corbett and an upgraded Circus Baby. The journey to the pizzeria caused additional damage to the already ruined Springtrap suit, degrading it to Scraptrap form.

Afton intended to find a way to do another Remnant transfer, this time into the pizzeria owner, but was thwarted several nights until it was revealed that the pizzeria itself had been a trap, set to incinerate itself and everything within it once all the intended victims were gathered in the location. Afton had just enough time to send an alert to the sister location facility of what was happening before he was consumed by the inferno, the lingering traces of his Remnant burned away.

Trivia

 * Elder Afton's Funtime designs were created first; the Fitzgerald Toy designs are actually copies, at least in appearance. Their software and A.I., however, were programmed radically differently.