8 ponies must fight an enemy that cannot be defeated.
8 ponies must use a unique power to protect a town they love from a string of kidnappings.
8 ponies must save equestria before time runs out.

Nightshade. A pony who lost his home and now moved to the small town of Ponyville to live with his sister. However once he arrives, the kidnapping rate starts to rise. Ponies start to go missing and never return. However 8 ponies are given a power known as persona to stop the kidnappings and rescue the missing ponies from a different world.

(Best image I could find)