Antecedent
Next was nightmare moon, and the six young ponies who took up the elements of harmony to defeat her, and return her to normal.
MLP: Believing in the Impossible - Chapter Nine
Yes, nightmare moon took princess luna away for the same amount of time. yes, celestia has her reasons to question our, destiny's, motives."
The Prince and the Gunslinger - Chapter 1
(after nightmare moon), you would see the otherwise fertile plains become hot and dry, the grass eventually wilting and giving away to a golden brown sand that stretches as far as the eye can see.
Antecedent 3
"i-it's not...nightmare moon?" "there's no way to know," sentinel responded with a shake of his head. "celestia has put the palace on full alert. the guards from the two castles no longer mix or exchange information.
My little Pony: Guardians of Equestria pt. 5
Just like nightmare moon, where she had to gain their trust, i too can gain their trusts." it was so weird, here was a youngling, only two years of age, maybe a bit younger, and yet...he spoke and held that much of wisdom; of that of a much older pony.
Giving Love a Helping Hoof: Chapter 3
Well, since nightmare moon." luna's gaze shifted for a moment, clearly uncomfortable. celestia came to her sister's rescue.
Chapter Seventeen: Things We Can Forget (edit 3/20/2015)
:d edit 3/20/2015: enhanced the conversation a bit and some stuff on why luna turned into nightmare moon. also a little more of my slow, secret process of reducing my use of pronouns not in speech.
MLP: Lunar's Return pt 3
This resentment opened up her heart to hatred and turned her into a wicked mare of darkness b the name of nightmare moon.
Little Star Chapter 2
The tale of nightmare moon started one thousand and eight years ago..." \* \* \* \* \* \* luna looked on with relief at the sight of her citadel. the citadel of the stars was her haven for her precious bat-ponies.
Through A Glass Darkly - 7 (final)
"i would think that the nightmare moon incident..." "if anything that was the inverse, a lack of power, not an excess," celestia smiled back. that was ancient history by now.
Birds of Paradise
During the abnormally long night that occurred with nightmare moon's return.
Not I: Murderous Mares / Betrayed
A flash of lightning lit the throne room through the stained glass windows; she could have sworn she saw nightmare moon in luna's place. twilight stood there, stunned at the realization. it was all a lie?