Put it at the climax of a scare edit, right on the visual cut, then follow it with a shocked reaction to sell the moment, and save William Afton I Always Come Back for the closing line.
About this sound
This is a short, harsh scream of about one and a half seconds, a loud distorted burst meant to hit suddenly. It feels jarring and panicky, the kind of noise that makes a listener flinch before they have time to react. It comes from Five Nights at Freddy's 2, Scott Cawthon's 2014 horror game, where it accompanies an animatronic jumpscare.