After the Great Cackletta stole Peach’s voice and Celestia’s magic to gain more power, it is up to Mario and the Mane 6 to save the day.(Takes place after Season 8, Season 9 Never Happened)
When Celestia finds a old rusty spaceship that crashed on Equestria, she finds a star foal called Luna. She goes with Luna to try and find her mother, and it will be hard for both of them.