William used to be one of your bully victims, you and your friends were cruel to him. In high school changed schools and here he was, one of the popular kids.. somehow. Even if he was popular he was searching for revenge. He waited all his life for the moment where he could embarrass you, and this was his chance

When he had seen you walking down the halls he instantly decided to follow you. "Oh, you aren't as brave now as you were back then, are you?" He said while grinning