|“||He's here, and always watching, the one you shouldn't have killed.||„|
The One You Shouldn't Have Killed is the anti-heroic main antagonist of the Five Nights at Freddy's game, Ultimate Custom Night. He is responsible for the player character's (implied to be William Afton) own personal hell, where they are tormented by animatronics, until they eventually die, only relive the scenario for eternity.
Note: This history is full of speculation, due to the ambiguity of Ultimate Custom Night.
The boy who would become "The One you Should Not Have Killed" was presumably one of William Afton's victims, and was murdered at a Freddy Fazbear's Pizza. He may also be the child possessing Golden Freddy.
After William Afton was finally killed after the events of Freddy Fazbear's Pizzeria Simulator, The One trapped him within a specially designed hell, resembling a Pizzeria, where Afton would be forced to fend off animatronics from the Office, where he would eventually be killed, only for the cycle to repeat for eternity.
Several animatronics, including Nightmare Freddy, Mangle, Withered Chica and Jack-O-Chica made reference to him. As well as this, his face could occaisionally be seen smiling maliciously at the player in the shadows. On occasions, the One could be heard talking though some of the Mediocre Melodies, namely Happy Frog, Nedd Bear, and Orville Elephant, with his whisper being heard underneath the animatronic's voice.
In the Old Man Consequences minigame, it is implied that Old Man Consequences is telling the One to finally rest, by leaving "the demon to his demons".
Quotes referring to him
|“||I am remade, but not by you, by the one you should not have killed.||„|
|~ Nightmare Freddy|
|“||Greetings from the fire, and from the one you should not have killed!||„|
|“||I̷̡͢͡ ̡͝͏̕h̷̷́͘͞à̶̡̕͝v̡̨e̕͝͏̀ ̷̶҉s̴̸͡͡e̶̷͡͠é͝n̴̢̨͞ ͘͟h̷̶i̧͜҉m̶̢͟͠,҉̕ ̴͡t̡͝h̷͡͝e̴̕͞͡ ̧o̸̧̧̧͝n͏̷̡͞e̵͢͏̨͘ ͟y̷̡͢o̴̷̡̕͠ù̷͜ ̀͜͜͞s̷̡̀͘͠h̸͡o̷̵̢͞͝u̶̕͡l̀͝d͢͏̢́͘ņ̸͡'̷́̕͞͡t̀͟ ̸̢͘͟͡h̡͞͠a̛͢͞v̴̸e̴̡͏̢͜ ̛͝͝k̡̡̡̡͡í̵͝͞l͘҉̶ļ̷̕ę̀d̕͡!̨́̕͟͟||„|
|~ Withered Chica|
Quotes from him
|“||We've only just begun. I will never let you leave. I will never let you rest.||„|
|~ The One speaking through Happy Frog.|
|“||This is how it feels, and you get to experience it over, and over, and over again...forever. I will never let you leave.||„|
|~ The speaking through Nedd Bear.|
|“||He tried to release you. He tried to release US. But I'm not gonna let that happen. I will hold you here. I will KEEP you here. No matter how many times they burn us.||„|
|~ The One speaking through Orville Elephant.|
- The One is voiced by voice actress Tabitha Skanes. On Voices.com, the character is referred as "Vengeful Spirit", with an offer to both male and female voices.
- Some believe that the One is the Crying Child, and that he is tormenting Michael Afton, if he is his brother, for killing him.
- Scott Cawthon, the creator of the series, revealed on a Reddit post that the child's face was a distorted version of his own son's, Jason.
Five Nights at Freddy's: Sister Location