How did the Beast become the beast, was he just an older brother with responsibilities? (Sets way before the show)

Nothing is every normal at Freddy Fazbear's Pizza. Especially for the night guards. Jeremy, is only doing this to pay for himself, and Mike, the former night guard that helps him along the way. They don't get along too well but if you have anyone that's close to a friend, they may save your life.

This takes place the same year Callaghan/Yokai is defeated. Hiro decides to visit a couple people since today's Christmas. Which just means he stops by the police station and the cemetery. This isn't related to my other stories. But is based off the movie in which Tadashi is dead. Enjoy!

What if Baymax followed Hiro's orders and killed Callaghan? (Spoilers)