"WHY DO YOU PUT THEM BEFORE ME!?!?"
The question hung in the air; it hadn't been said or asked or even shouted. It had been screamed. Screamed in desperation from a pony who had been pushed to the brink of desperation by everyone even her own family. The mare was screaming at her sister, only 6 feet away but at the moment it felt like she was 6 miles away.
"DO I NOT MATTER ANY MORE!?!?"
An equally frustrated question.
"DO THEY MEAN MORE TO YOU THAN ME!?!?"
A third question. But none of these questions would get the answer the mare was seeking. She knew she would never get the answers she was seeking; not from her sister, not from the pony opposite, standing in the light of her glow and power not to even mention their love; their precious subjects love.
No, not their subjects. Her subjects.
They had only loved her, showered her with compassion and admiration while only giving the now desperate screaming pony coldness, bitterness and hate. Tears were streaming the mare's eyes willing her sister to finally listen to her, to not be ignored, to not be passed over.
The mare looked into her sister eyes, those perfect eyes that her subjects adored, that always never had the answers to her questions.
"YOU HAVE TO CHOOSE!!!"
The mare screamed at the other again.
"EITHER ITS THEM OR ME!!!"
She waited for the reply or any kind of answer from her sister. She waited. And she waited. Once again as with all the other times, no answer was given. Her sister for once looked shocked, not even the countless years together with each other could prevent the expression of shock and horror from appearing on her precious perfect face. Finally she replied with an answer that was barely more than a whisper.
"Y-you can't ask me to choose, please, don't make me choose..."
The mare let a scream of rage that shook the ground around them. Of course her sister wouldn't choose, she would never choose. Her sister who held both her subjects and the mare 'equally'. By that very definition she would never be equal to her sister's subjects. She was supposed to be family!!!
But no, if her sister prized her subjects over her; then she had no family. And she will make her former sister pay for her choice.
"FINE THEN! YOU HAVE MADE YOUR CHOICE, NOW I WILL MAKE MINE!!!"
"W-what!?!? B-but I don't understand........."
Another wave of rage ripped through the mare, cutting deeper than the last. Of course her sister wouldn't understand; she had never understood, she will never understand the pain of being ignored. Not until her dear sister felt as the mare felt had; to lose everything and everyone close to her, that in itself was the answer.
Make her understand.
Make her lose everything as the mare had; her family, her friends and then finally herself. And the first one was easy.
"S-sister, please...."
It had now been made even easier. The mare would have let of a shout of laughter if she wasn't filled with rage and anger at the moment, but she could always it try for laughter if she wanted to. But instead of laughter, the sound that filled the air was more like a raw bark of animal; wild and untamed. The mare's tear stained eyes turned back to look upon the pony in front of her. Directly looking into each others eyes; one filled with anger the other full of sadness.
"I HAVE NO SISTER!"
The words pierced the air like nothing before it, driving the point across the gap between them with brutal efficiency. The sister stepped back in hurt like she had just been on the receiving of a physical blow. She had never would have imagined the intensity of amount of pain those words had just cause but she did know one thing; the mare who had screamed those words had meant them.
Through this, both their eyes had remained locked on each other, neither of them daring to look away from the other.
"TODAY YOU HAVE MADE YOUR GREATEST ENEMY!!! I WILL TAKE FROM YOU EVERYTHING!"
"I WILL RUIN YOUR MISGUIDED PLANS AND SCHEMES THAT YOU SO DESIGN AND ACT ON, I WILL TAKE YOUR PRECIOUS SUBJECTS THAT YOU SO PROTECT AND THAT LOVE YOU SO MUCH, I WILL REMOVE YOUR POWER THAT YOU SO FOOLISHLY MISUSE FOR MY OWN, I WILL SHATTER YOUR FAILING HOPES THAT YOU SO DESPERATELY CLING TO AND THEN WHEN YOU FINALLY UNDERSTAND HOW AND WHY I WILL DO THESE THINGS THEN I WILL FINALLY GRANT YOU THE END THAT YOU SO RICHLY DESERVE!!!!!"
In the middle of this speech the mare had started to change, her coat had shifted from a light royal blue to a deeper shade resembling dark violet, an almost dark blackness where no light could possible pierce it. Her mane that had reflected a open starry night had condensed into a shifting mass of deepest darkest black with only a few major stars managing to make an appearence. Her horn elongated to resemble her sister's. Her wings lengthen to almost double their original size. Her silver crown had morphed down to become a helm of light-taking obsidian, armor of the same nature grew around her body as if summoned from the very air itself; transforming the silver torc around her neck into some kind of cruel obsidian breastplate. Her eyes slowly became more dragonesque; the pupils slitting, while the whites became a slightly lighter shade of the same colour as her irises; a deep aqua green. Her teeth no longer normal; now fangs lined her mouth as she split a wide manic grin.
"L-l-luna......please......" whispered Celestia, who could only watch on in horror at the transformation taking place before her very own eyes.
But Luna was gone, now there was only Nightmare Moon......

Author's Note
So, I hoped that you guys/girls/ponies liked this short story.
I will hopefully write more when a scenario takes my fancy.
To be honest, this kinda of came about from watching all the MLP Luna episodes in a row.
............
"TODAY YOU HAVE MADE YOUR GREATEST ENEMY!!! I WILL TAKE FROM YOU EVERYTHING!"
"I WILL DESTROY YOUR MISGUIDED PLANS THAT YOU PATHETICALLY HOPE UPON, I WILL BURN YOUR PRECIOUS SUBJECTS THAT YOU PROTECT SO FIERCELY TO ASHES AND DUST, I WILL TAKE YOUR POWER THAT YOU HAVE NO IDEA HOW TO USE, I WILL SHATTER YOUR FAILING O' SO POWERFUL DREAMS THAT YOU DESPERATELY CLING TO AND THEN WHEN YOU FINALLY UNDERSTAND HOW AND WHY I WILL DO THESE THINGS THEN I WILL FINALLY GRANT YOU THE END THAT YOU SO RICHLY DESERVE!!!!!"
In the middle of this speech the mare had started to change, her mane that had reflected a perfect four-striped colour tone had condensed into a shifting burning mass into three ferocious colours with actual heat dissipating from her mane. Her horn elongated to resemble twice of her sister's. Her wings lengthen to almost double their original size. Her crown had morphed down to become a helm of light-giving gold, armor of the same nature grew around her body as if summoned from the very air itself; transforming the torc around her neck into some kind of cruel golden breastplate. Her eyes slowly became more dragonesque; the pupils slitting, while the whites became a slightly lighter shade of the same colour as her irises; a deep violet purple. Her teeth no longer normal; now fangs lined her mouth as she revealed with a fierce derisive sneer.
"C-c-celestia......please......" whispered Luna, who could only watch on in horror at the transformation taking place before her very own eyes.
But Celestia was gone, now there was only Radiant Malevolence......

Author's Note
Set in Equestria-6.
AKA: The LunaVerse
Picture produced by TheStoicMachine