"Shift Complete" comes from the soundtrack of Five Nights at Freddy's: Sister Location, the 2016 FNaF game. Fans recognize it as the short completion cue tied to finishing a night or section, which made it easy to reuse in edits about survival and payoff. Online, it spread through gaming clips, FNaF compilations, and meme edits where a tense sequence suddenly resolves. It stays popular because it is short, instantly readable, and connected to the series' familiar mix of dread and relief, much like a FNAF Jumpscare Scream works for the opposite moment.