When a colt named "Bad Dude" storms into Celestia's personal study and declares himself as her latest arch enemy, the Princess can't help but nearly gush from the sight. But is there more to "Bad Dude" than his cute exterior would suggest?
The princesses gave their magic to Twilight to prevent Tirek from stealing it. As a result, they end up stuck in Tartarus. The fact that things manage to go downhill here says a lot about the wonders of family.