"THE NIGHT WILL LAST FOREVER!!!" As soon as Nightmare Moon claimed this, a young filly with a white coat, midnight blue mane and tail, bat-wings, fluffy hears, and cat-like eyes with colors making them look like an aurora borealis walked from behind the scene and asked "But if there is no more day, when will my friend and I go to bed?"
The Nightmare could only look bemused at the filly, who looked inexplicably familiar to her. Was it someone she knew? No, no, impossible! Only an alicorn could live that long!
Unaware and uncaring of the fallen princess’ musing, the bat-filly added a second question. "Have you forgotten about my kind?" Actually, that was a good question. Nightmare Moon had memories of nocturnal ponies like this filly, but before she joined her on the stage, she hadn’t remembered their existence. It was like something was actively preventing her from thinking of those night lovers.
"Then let me refresh your memory," said the young pony, now looking angry. "It all started when the previous princess of the night, a mare called Luna, met a strange little pegasus filly. Thanks to her powerful alicorn magic, she could feel said pegasus had been cursed, turning her into a vampony. The curse was too strong to be broken, but it could be altered, turned into a blessing of sorts, and it exactly what princess Luna did."
"Thanks to the princess, the filly could go under the sun without turning into cinders. And while she kept the ability to feed on blood, she also regained the ability to feed on plants, albeit with a greater need for fruits in their diet than mort ponies. She also explained how the group of unicorn that had cursed her had killed her parents in front of her eyes beforehand."
Some had noticed how her vocabulary was too vast for a filly of her apparent age at that point, like Cheerilee and Twilight Sparkle, but nobody dared to interrupt, especially not since somehow that little pony seemed to scare the Nightmare.
"After this, princess Luna discovered more ponies under the same curses, and offered them the same 'cure'. Most of them were pegasi, but there was also unicorns and earth ponies. All of those became extremely loyal to the princess they saw as their saviors. As for the first filly that was found with the curse? Princess Luna eventually adopted her as her own daughter! And for a time, the princess really was a mother to her."
"But suddenly, without any warning, the princess acted like couldn't see nor hear those ponies, who had started to call themselves Noctrals. As a final backstab, she even started to complain about nopony caring about her night, growing jealous of the apparent 'favoritism' her subject seemed to have for her older sister, the sun princess named Celestia, slowly turning into a creature known as… Nightmare Moon."
"While Celestia fought her maddened sister, the Noctrals helped the solar guards to evacuate the civilians, to minimize the number of collateral victims of that fight. But regardless of the help they had given against Nightmare Moon, in the mind of Equestrians, the 'bat-ponies' were still seen as followers of the fallen princess, and were persecuted and slaughtered, even with Celestia severely punishing all who mistreated Noctrals."
"The few survivors felt their magic evolving, granting them a glamour that would let them appear as ordinary day-ponies." As she said this, the Noctral filly turned into a pegasus of the same colors. But it was little more than an illusion, a 'trick to the eyes', so to survive the Noctrals decided to hide themselves in the only place no other pony would dare to disturb them, too scared of it: the Everfree Forest. There, on the ruins of the castle of the two pony sisters, they built the independent city of Noctralia."
"As for the filly Luna had adopted, she did two things after her former mom had been sealed on the moon. The first was try to pick-up the slack from you, dear Nightmare, and try to raise the moon, even though she had no horn. Somehow her determination make her ascend to alicornhood and become the new princess of the moon. The second was to change her name, because it might have been a nave given to her by her biological parents, it also was the one Luna used. As such hearing it again hurt." Again the filly on stage changed, except this time she wasn't a filly anymore. She looked like a particularly tall adult version of the bat-filly from the start, with a horn. She was somewhere between Celestia and Cadence in height. Her mane and tail, while still of the same midnight blue, were as ethereal as Celestia's and full of stars. On her flanks was a cutie-mark similar to Nightmare Moon's, but the background splotch was the same midnight blue as her tail instead of purple, and the white crescent moon in the center was encircled by 4 white stars.
"It was my hope that, after 1000 years on the moon, you would revert back to being Luna. It was in vain, clearly." The unnamed alicorn put her horn against Nightmare Moon's, the two briefly glowing. The fallen princess' mane and tail lost heir ethereal quality, along with their stars, and her cutie-mark disappeared. "I cut your connection to my moon and stars, hope it took away your ability to visit ponies' dream too. Seem one of the side effect seem to be the loss of your cutie mark." After a pause, the alicorn of the night added. "Make sense, you can't have the special talent of making the night if you can't bring out the moon and turn on the stars…"
As the mysterious alicorn turned her back to the Nightmare, slowly walking toward the backstage, the fallen one partially got out of her stupor. "Winter Night? Is… Is that you?"
At this, the supposed Winter Night whirled around and violently slapped Nightmare Moon. "DIDN'T YOU LISTEN TO MY STORY?!? I CAN'T STAND THAT NAME ANYMORE, AND IT'S BECAUSE OF YOU!!! In a way, Winter Night died when you forgot about her and fell to your jealousy. All that's left in her place is Morphée, supreme commender of Noctralia. Because that's the problem hiding a city in the heart of the Everfree, it can't survive without a strict discipline. I was forced to turn Noctralia into a military state. Hopefully we can slowly reintegrate with Equestria now…"
Commender Morphée then called "Lieutenant Aurora Specturm!" and a Noctral unicorn appeared on the stage near her. Her coat was as black as the Nightmare's while her eyes looked like Morphée's. Her mane and tails looked like Rainbow Dash's, but with the colors of an aurora borealis. An aurora borealis was also what she had for a cutie-mark.
"Yes, ma'am?"
"Make sure she doesn't try anything while I lower the moon and bring out the sun," said Morphée, nodding in the direction of the mare that used to be her adoptive mother. "And don't let anyone hurt her either, I'm sure Celestia will want her alive and in one piece."
Author's Note
I know it’s cruel to end a story on a cliffhanger, but I don’t have the inspiration for what come next. If that change, then I will add more chapter(s). Otherwise, anyone with said inspiration can write a sequel. 
