Since Twilight helped Luna in Nightmare Night, Luna has started to develop feelings of love for the unicorn, and she wants to confess what she feels. But first, she must eliminate anypony that is close to Twilight.
Luna feels sorrow, pain, deapir, and is lonely. She feels fear and pain, and slowly watch as this eventually turns her into a Nightmare Version of herself. This is the stroy of the transformation and change of Luna into Nightmare Moon.
A short story based on "MLP: The Light of Equestria" by https://www.fimfiction.net/user/Courageous-of-Light, which can be found on Deviantart. This explains what happened after the unicorn, Firm Hoof, was banished from EInhorn, and went to find Tirek
So, it appears the rumors are true...DJ Pon-3 and even Rarity have been bitten by bat-ponies...vampire ones! Vampire bat ponies are now common in Equestria, but who would have thought that two heroes would have been affected by them?!
Nightmare Moon and Nightmare Rarity return to Earth. Nightmare Moon aims to cause eternal night and Nightmare Rarity as well, but she also intends to try again to conquer Nightmare Moon. Will she succeed in winning Nightmare Moon's heart this time?
What else can your destiny be, if the circumstances of your birth are so dark? This is the story of Nightmare Moon's origin, the very first Nightmare Force.
How blessed are the lives of the dead. They exist solely to present the blissful peace of rest eternal. Rest is my most prized commodity, now. For, when in Reba, there is no rest. I am Princess Luna, lord of the night sky, for me, there is no rest
Tiffany "Twilight" Sparkle always thought of friends as a waste of time, at least until she was forced to team up with five strangers in order to stop Nightmare Moon.
With the defeat of Malgus and his empire, Charming Thunder along with Starswirl the Bearded brought back the Crystal Knights. Now the essence of Nightmare Moon returns and posseses Charming Thunder and plots her revenge.