It's one thing to create/throw already-established characters in a story of some kind. It's another thing to develop those characters, regardless of the situation they're in.
Before Celestia and Luna, Equestria was a barren landscape. When two celestial beings descend from upon high, they bring with them two fillies that will bring Equestria to glory.
The two puppets, Vivi and Kuja, had just learned what it meant to live when their lives ended. Blessed with second chances, they find themselves in the relatively peaceful world of Equestria.
After Princess Twilight's second coronation, word has come from the south that a great evil has returned. Will the Elements of Harmony be able to stop it in time, or is Equestria doomed?
Once upon a time, in a faraway land, there was a young Empire by the name of Crytsallus. Legend tells of a horrible beast that threatened the residents. It also tells of the pony that risked it all to protect them.