There was a reason that monsters were powered more from laughs than screams.
AN: I do not own Monsters Inc; all profits would go to Disney if I were making money off of this.
Long before James (Sully) Sullivan and Mike Wazowski rediscovered that the laughs of children powered their city better that the frightened screams of the same, it was widely acknowledged by all of their kind. You see, monsters weren't always the villians- they were once the warriors, the protectors of innocence, the heroes of their stories. They would go to war for a noble cause, grim smiles on their faces.
You see, the monsters weren't there to scare the children. They were there to protect them from a far more sinister force: their parents. Their sinful, horrible parents, the tainters of innocence, the destroyers of innocence and joy. They kept the predator of sin from their charges until they rejected the monsters. They waged wars against human demons, loving their children. It was instinct, ingrained in their very being.
"You're fully human, completely and absolutely? I've heard some awful things about humans. Are you really sure?"
Humans are awful creatures- truly, wholly awful, absorbed in our short, petty lives and squabbles and hate. They don't need a weapon; they are born weapons. That is what the monsters tried to protect us from, once upon a time. They protected you from the nightmares, the hate, the violence and war, for as long as you let them.
Oh, but how the mighty fall. Stories spread, vilifying the monsters. 'They ate children, naughty children who disobey their parents,' the adults claimed, and the children believed them, wide eyed innocence perishing ever so slowly that the monsters never noticed.
'Demons of the night,' the noble protectors were called. 'Witches, Wendigos, child killers, evil spirits. You must not listen to them, child, for they will consume you.' So said the parents, and the 'monsters' lost their war before it ever began.
The monsters became outcasts, rejected, thrown from the lives of their charges. Monster became a vile, hateful word, used only in disgust, in loathing and fear.
Because to you, I am an atrocity. And that is all I ever was. It's okay that you don't love me. I still love you enough for the both of us.
But now, Sully and Wazowski relearned the ancient teachings. Today, the monsters have learnt their past, even in their ignorance, and shall soon resume their post as guardians of humans. That is, if only the parents are felled, one by one.
Boo was the first to recognize that the monsters were not bad.
"Why do they all fear you Sully? You're not bad."
Rejection is the worst form of torture. Especially from a loved one. And the monsters were rejected for being the heroes of the stories. Eventually, they became the villains. After all, everyone known that humans create monsters- not the other way around.