Long ago, when there wasn't much in Equestria, two watched over the land. Lux, a powerful alicorn mare, and Tenebris, a strong-willed alicorn stallion. These two established what would be known as the High Majesty, a group of individuals responsible for managing Equestria. This included the two you all presumably know, Celestia and Luna. After the earth ponies, unicorns, and pegasi populated Equestria, the Majesty realized there was much more to keep under control. The chaotic lives of many individuals pooled together and became Discord, so to keep him in check, the High Majesty sealed him in stone. Soon, more and more beings were created, Queen Chrysalis and King Sombra to name two, and the Majesty soon realized they needed protection. They enlisted the first Stargazer, Lumino Solari, to control the constellations and use them to defeat the forces of evil. However, there was one who was cunning enough to see through this stellar defense.That pony possessed Solari and used him to reek havoc over Equestria with the constellations. To stop this from happening again, Lux and Tenebris banished both Lumino Solari and the mysterious pony to the Dark Void, an empty realm in space. After 5 millennia, that evildoer is back...

And he seeks revenge.