Meet Auraera the eldest sister. She maintained the stars in the sky. ~ "...the stars will aid in her escape and she will bring about nighttime eternal."
Who were the stars? >.> ~ 1000 years ago Auraera turned Luna and Celestia against each other. In doing so, she hoped that they would kill each other and leave her as the only ruler in Equestria.
But she didnt count on Celestia being unwilling to kill Luna. Since Celestia lacked the power to stop Luna's violent rage, she used the Elements of Harmony to imprison Luna in the moon.
Celestia knew Auraera was behind this, and she wasn't about to let her sister get away with it.
Auraera couldnt fight Celestia while she wielded the elements, so she fled Equestria.
When Celestia reached Auraera's castle, all she found was a child. Celestia had no idea Auraera had a son. There was no signs of Auraera or the childs father anywhere.
Celestia was to busy restoring order too take care off her nephew, so she found him a home among the nobles.
1000 years later Auraera freed Luna in hopes of finishing what she started... ~ This is my entry for the contest at
And if anyone is wondering its pronounced (or-rare-ah)
My theory does include a sister of Celestia and Luna (who is, of course, a princess and ruler of her own kingdom), except she's not evil and that Blueblood's her son by law not by blood (as in he was adopted.).
It's part of a larger work-in-progress.