Author of letter unknown. Letter was found in Princess Celestia's bedroom one day before the Equestria Games:

Dear Princess Celestia,

This peace has gone on for far too long, don't you agree?

Now I'm sure that you must be thinking about all the times our kingdom has been threatened recently. Your sister's return, Discord's return, our unfortunate neighbors, Sombra's return. I'm sure that everypony must have thought that each was the doom that would bring us to our ruin, but the way I see it, each was just another failure failing again.

These so called villains, what have they accomplished? Our world has forgotten what a real villain is, and I think it's about time that changed. So, my princess, if you and your team are ready, then so am I.

See you tomorrow.

Takes place in an AU season 4. The episodes of season 4 and Equestria Girls never happened.