Let's look deeper into how the Mane Six would act if they were the villains. Examples might be: Twilight and a desire to have all the intelligence from all the ponies, Rarity and a wish to be the only fashion designer that everypony knew, Rainbow and a wish to be the only Wonderbolt, Fluttershy and an animal army, Pinkie Pie being the party pooper, and AppleJack making sure that everyone ate only apples?? Just be creative! There doesn't have to be a happy ending. Happy Writing!