In my opinion William Afton could be the protagonist from Five Night's At Freddy's 3 since the protagonist is completely anomynous nothing is know of the protagonist other than he got a job at Fazbear's Fright and lit it on fire perhaps the spirits were still out for vengenance and William decidede to go to Fazbear's Fright applied for the job and wanted to destroy the evidence but on the second night he found Springtrap Springtrap might have recognized William and tried to kill him for everything he had done on the fifth night William took gas cans to Fazbear's Fright and prepared to burn everything to the ground knowing that the spirits still was linked and wouldnt stop haunting him until he freed them of their link to the suits like his daughter and the other animatronics from sister location.