After the death of William, everything changed.Freddy had gone mad. His father pressured more, and he was knighted in the Angel court to protect heaven from demons. So the say William walks in the pizzeria, Freddy could smell the filthy sinner. 

" hello Fazbear~" he chuckles. Freddy turns. "Afton." He pulls his sword out, growling. But this time, Hunter was their. With a handgun. Pointed at the back of his head. "You're gonna kill me..like my mom..?" He snarls. 

William glares,"Fazbear...you …" Freddy cut him off by kicking the shadow back and stabbing the sword into williams chest. He pants backing up, as the demon shrieks.. standing. He rips the sword out, coughing. Freddy screams, but sees William tear his down chest open and tear his heart out. "You did this~" he chuckles, taking a bite out of his own heart. He spreads his wings and crushes his heart. 

Hunter stood slowly, but Bonnie tackles him, and the two battle silently, as Freddy and William circle each other

This was never going to end