Well, we all know what happened all those years ago, don't we? Luna became Nightmare Moon and fought Celestia, which killed her, but not before she sent Nightmare Moon TO the moon. Celestia was replaced by Crystalia, her best friend who also happened to be a Changeling, and she was Celestia until recent events caused her to be revealed. But recent events also revealed another thing, one that had supposedly been evil, and destroyed on the Day of the Summer Sun one thousand years after she'd been banished.

Recent events revealed Nightmare Moon, herald of the Eternal Night, was still alive and kicking, but not kicking the rumps of the Princesses, no. She was fighting in the name of the Princesses. What could cause such a change in such a cruel alicorn and, on another note, how was she still alive?

Read on, friend, and all shall be revealed.