When William was young, his mother died of cancer, causing him to live alone with his father. Slowly, his father's substance abuse(due to depression) caused him to abuse William and his younger cousin. His father coerced him to kill his younger cousin, leading to a more traumatizing life for William. Eventually, he ran away from his father's house.

After spending a few years in an orphanage, William married Eleanor Schmidt and sired two children, Michael and Elizabeth. Their life was happy and William decided to open Fredbear's Family Diner to entertain the local children. An American named Henry Emily visited the establishment and offered him a way to open a new location in the US. After William's third son, Tristen, was born, he and Michael moved to the States to run the business with Henry.

William began to have anxious nightmares about the deaths of his family members, so he decided to take a page out of an old children's book that his father used to read him and began killing children to make his family immortal. Even to the point where Elizabeth and Tristen were both accidentally murdered by his makings. William injected Michael and himself with the "soul remnant", causing them to both become immortal and impervious to certain pains.

After Michael left due to anger, William began killing more children in secret because the police were on his trail. In 1992, William goes to dismantle all of the original animatronics(now possessed) and gets surprised by the ghosts of his victims. He jumps into the nearest springlock suit, and gets crushed due to "malfunctions". After that incident, he was sealed in a storage room by Fazbear employees.

30 years later, an amusement park builds on top of the old location and frees William, now Springtrap, from his prison. He escapes the electrical fire there and roams around causing minor mayhem until he happens upon a new Fazbear location that seems all too easy to invade and murder.

As it turns out, the new location was owned by Henry and was a trap to free all of William's victims and kill William himself. William dies in that fire.

***

William Afton isn't just some 2D killer. Maybe in the games, he is, but not in this story. Here he has depth, motivation, backstory, and is a relatable human being.

Being the person he is, doing what he did, makes the games feel less hollow. Less cliche.

William wasn't a very hard character to write due to all the framework laid out for him, but that didn't make it 100% easy either. It was very very fun as a result.

But this guy doesn't have a very in-depth character file because most of it is told out in the story.

For those of you wondering his whereabouts between the ending of FNAF: Insanity and the events of FNAF 3, look no further than the "biography" above. That's really all he was doing. The problem with post-FNAF: Insanity William is that he's gone off the edge. He's not a human being anymore, so writing about him in a narrative format would prove futile. That's why he was barely mentioned in FNAF: Redemption as well. He's not human anymore.