REWRITE

Once upon a time, when Equestria was young and recently united under the Princesses, a tall, imposing creature bearing a crown of thorns and three weeping faces appeared from the depths of the Everfree seeking a master. When it was brought before the Princesses, they gladly accepted it into their ranks. But when one of the sisters rose up in rebellion, the creature refused to help either side. So when the elder sister sealed away her sibling and left the castle, it remained. Now the sisters are together again, and have set out to reclaim their lost friend.