The land of Equestria was always one filled with light and positivity, but the darkness has been amassing, the Sin, embodiments of the evil of ponies' hearts and souls, have struck, many ponies have died, and only 4 centers of civilization remain, Canterlot, Ponyville, Bearussia, and Neigh York, the last vestiges of hope for ponykind, and they are mere motes of substance waiting to be consumed.

Princess Luna, a powerful mare who has seen first-hoof into the abyss of darkness and evil, has used her and her sister Celestia's magic to summon warriors of light, heroes that will save the land of Equestria.

She was expecting 1, 2, maybe 3 tops, and if Lady Luck was on her side, 4, but she received, not 5 or even 6, but 15 fighters to help this task.

That's not what was surprising about them, what was surprising about them was that they were not even ponies.