A Jedi knight runs into a new technology on the planet Corellia during the Clone Wars. As he's escaping in his ship, the Shadow, a dimension shifting device transported him to a technologically advanced Equestria. He can't get back to his dimension because the device disintegrated after shifting him into Equestrian galaxy from hyperspace. He finds that their galaxy has no Jedi protectors, and vows to help the ponies defeat the Sith.

*Equestria is as advanced in technology as the Old Republic Star Wars galaxy, and only their version of Sith have lightsabers. The Equestrians don't have Jedi.