Zero is the main antagonist of Abandoned and Zero Regrets and made his appearance late in the story. His intentions are very specific being he still wants to destroy but has a light heart still inside of him.
Zero was originally the old model of FredBear before 1978. In 1978 the first model of FredBear was scrapped and was replaced with a different model. The old model was sent to the Fred's Dining productions factory to be kept in a parts & service room to be used for anything else. Over the years the model was decaying and turning yellow and started to spark. Then during a night hour (about 9:27 PM)in 1980 a man in a purple coat came up to zero and gave him a new circuit part and also a magic substance causing the old FredBear model to get his own mind! After the man disappeared, FredBear found a worker and killed him. FredBear then re-named himself Zero The Destroyer as he thought that Fred Bearins (FredBears family diners owner) wasn't appreciative of him and saw that people were only going to be in danger more and only would be trouble for him, along with that Zero knew he had a new power and he could use it for good. Later that night a fire started in an apartment building close to the factory zero saved the people but they didn't accept him as a hero. They called him "Terrifying", "A monstrosity" and even calling him "Useless." to the point Zero left and found the purple coated man again. The coated man told Zero "That if they don't accept you NO ONE will! You'll be hated on by them because they can't see you're full potential! You must show them what you feel and do what they did to you..." Later Zero tried to figure out how he could do that without truly hurting anyone harshly. But the coated man said only one thing could be done. Zero was given more of the strange substance making him stronger and turning him purple and smogy. The main nodded his head and said "Get 'em, pal!" and simply vanished. Zero's dark side took his upper mind and made Zero go insane and mad. Zero then began planning a way of conquering the world and seeking vengeance upon every human alive. He planned and planned and used humans and transformed them into demons with a machine he created in his newly found base. Zero soon had an army of 352,489 to lead and they all helped him further in his plan for world domination.