Sunset Shimmer tries to build her life back with her new friends. After what she has done to the student body of Canterlot High. But as a new group of villains called the Dazzlings come to the school during the Musical Showcase, the Dazzlings hyptnotize the student into making the showcase into a battle of the bands.
As Sunset tries to figure out what's going on, CoverGirl, ShipWreck, and LifeLine from G.I.Joe are watching over the school after what happened after the Fall Formal. Sunset Decides to get the aid of Twilight Sparkle. She tells them the Dazzlings are Sirens from Equestrian, banished to Earth by StarSwirl the Bearded over a thousand years ago. And have been hiding from people all that time. While also causing many of the world's problems, like wars.
Twilight decides their band, the Rainbooms, need to create a musical counter-spell against the Dazzlings to stop them for good, before the student body rips themselves apart.
Mid-Credit Scene Shows Human Twilight Sparkle figuring out the strangeness going on at the School.
2nd Mid-Credit Scene has the Dazzlings in G.I. Joe prison.
After Credit Scene has LifeLine do the G.I. Joe PSA.
