Ultimate Custom Night
It is most likely that the one you should not have killed is the likely leader who is commanding the anmatronics in the dimension that William Afton is trapped in and has the inability to die.
|“||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!||„|
|“||He's here, and always watching, the one you shouldn't have killed.||„|
|“||I̷̡͢͡ ̡͝͏̕h̷̷́͘͞à̶̡̕͝v̡̨e̕͝͏̀ ̷̶҉s̴̸͡͡e̶̷͡͠é͝n̴̢̨͞ ͘͟h̷̶i̧͜҉m̶̢͟͠,҉̕ ̴͡t̡͝h̷͡͝e̴̕͞͡ ̧o̸̧̧̧͝n͏̷̡͞e̵͢͏̨͘ ͟y̷̡͢o̴̷̡̕͠ù̷͜ ̀͜͜͞s̷̡̀͘͠h̸͡o̷̵̢͞͝u̶̕͡l̀͝d͢͏̢́͘ņ̸͡'̷́̕͞͡t̀͟ ̸̢͘͟͡h̡͞͠a̛͢͞v̴̸e̴̡͏̢͜ ̛͝͝k̡̡̡̡͡í̵͝͞l͘҉̶ļ̷̕ę̀d̕͡!̨́̕͟͟||„|
|~ Withered Chica|
- It is most likely that the one you should not have killed is some sort of leader.