Just a normal day traveling through the 'verse on Serenity, then Mal finds that his ship has been invaded by talking technicolor ponies, and the crew didn't tell him until 10 minutes after.
Sunset Shimmer inherits the power of 'One for All' to attend Beacon Academy. Secrets of Headmaster Ozpin rise making every students' lives more interesting.
An alternate universe where Twilight and the rest of the main six have younger, nearly identical, twin brothers. All of whom are preparing for the Summer Sun celebration before Nightmare Moon oh-so-rudely interrupts.