"Sister, you have given us no choice!"
Celestia stepped back. "What do you mean?! I don't understand!"
Luna filled with dark magick, the old kind that ran through fear and danger. "Your ponies shun the night that we have strived so hard to make!"
"They're our ponies, Luna! They need both of us!"
"You lie! They hate our glorious creation! You see it!"
"NO! Please, sister, look! They have written thousands of books on your sky, study it to learn about space! Expand their horizons using your moon as a target!"
Luna drew her head back and hissed, her eyeteeth beginning to grow sharp. "FINE! Send us into the space your ponies love to explore and hope they find us!"
Celestia sat back on her haunches, looking at her enraged sister with teary eyes. "This isn't you."
The darkness flooded out of her angry form, the sky darkening further for a few moments before disappaiting. Her Regalia changed from it's pale blue form to silver and black, and the shining shoes clicked back down on the floor. The Lunar Princess folded her wings and ducked her head, embarassed.
"We are sorry, sister. We did not mean to embrace the Nightmare again."
"It's okay. I know it's hard." Celestia trotted up to her younger sibling, gently nuzzling her head. "I understand how you hate staying up all night with nopony to talk to."
"It is... difficult, yes."
"I'm sure I can find some ponies willing to work on your schedule. There must be-"
"No. You are able to deal with becoming attached to your subjects as they grow older. We would not feel right taking ponies from their families to provide mere company until they pass away as years pass. We would enjoy being alone than living among death. We... we will be fine..."
"If that truly is what you wish, Luna."
The blue Princess nodded, watching as Celestia glanced up towards the clock tower. "It is almost time to set the moon. Do you want me to take care of it?"
"We'll be okay, 'Tia. Go get a few minutes of rest."
-----
"Do they really? Do they really enjoy our night?" Luna shouted into the dark sky. "Would they care if we were to disappear?"
The shimmering pheniox sitting on her shoulder let out a mournful chirp and rubbed it's golden head on her cheek.
"Thank you, Philomena. It is good to know somepony understands. You can leave at any time, flee this place, yet you do not. Why?"
The eternal bird looked up at the sky, the millions of stars reflecting in her dark black eyes. "Shckreet."
Luna matched the bird's gaze, looking up into the heavens.
"Celestia controls the sun. But we control thousands. Don't we?"
Philomena gave her lunar companion a worried look before spreading her wings and flying away, leaving a comet-like trail over the sky as she circled the castle's many towers.
-----
"Sister! Where are you? We're under attack!"
"Under attack!?" Celestia's bedroom door flew off it's hinges, splintering on the wall oppisite. Her hair was almost crimson with rage. "Who would attack us? We have no enemies!"
The solar princess suddenly stiffened with an inexplainable terror, rooting her hooves to the floor. With a molasses speed, she turned her head and looked up the hallway.
A black Alicorn, smoke wisping from her body, stood in the middle of the red carpet. Her mane swirled with navy nebulas, sparkling stars occasionally falling from it, only to burn out on the ground. The creature's pupils were daggers, and fangs slid over the lower jaw when it smiled.
"You have one enemy, sister. Us."
"Luna? Luna! No!"
"You should have seen it coming, Tia. We have been testing the extent of our control ever since we found the magick. You of all ponies should have seen the signs!" Luna's voice went even louder on the last word, sliding Celestia a few hooves back. "You lied, before. Only minutes before. There are never ponies out at night. They hate the cold it brings, the things that can hide in our shadows."
"Listen to yourself, Luna! Listen to me!"
"WE'VE LISTENED TO YOU MY WHOLE LIFE!" Luna roared, charging forward, sharp horn lowered, eyes glowing with fury. "WHEN DID YOU LISTEN TO US?!"
Celestia blew a hole in the roof, flying up seconds before Luna's black horn speared the air where she had been standing. The dark creature snorted before following her, feathers solid and glinting like they were made of steel. Celestia hovered, looking sadly at this... thing... in front of her.
"Luna, this isn't you."
"That is always your excuse. But if it wasn't us, then what is? Tell us, sister! What are we?!"
Celestia shut her eyes against the rage lancing from the dark Princess.
"You are my best friend. You are the one who was always there to comfort me when things went wrong, just as I comforted you. You are the creature I love most in the world. You are the respected Princess of the Night, the one who is known for making such a beautiful, beautiful sky. You are the one who always keeps me going, who keeps an eye over our kingdom while I rest, who smiles and laughs and cries and feels with me, and helps me when I need it and accepts help when she needs it. You are... you are my sister..."
My... sister...
The words floated in the air, strengthening the silence between the flying two. Celestia hung her head, golden tears running down her cheeks, while Luna had her neck in a graceful, surprised arc. Their wings beat against the ebony sky.
"We are sorry, Celestia."
Although the voice held no sadness, only a drawling sarcasm, Celestia looked up hopefully.
"It was our mistake."
The creature's eyes were closed, but a line of white light ran along the thin line between the eyelids.
"We cannot figure out where we went wrong."
Celestia's eyes lit up with happiness as she smiled, slowly gliding closer to embrace her sister.
The eyes flashed open, glaringly white. "You really should be dead right now."
The ivory Alicorn flared her wings, stopping her slow approach. "What?"
"We went wrong. We miscalculated. You were too fast."
"I don't understand."
"You wouldn't. I'm not lowering the moon tonight, sister. Not ever, actually."
Rage bubbled in the Princess's heart. With an angry roar, she charged, tackling the shadowy Alicorn with two solid golden shoes to the chest. Celestia flew down, the black creature pinned under her gravitational speed, squirming for freedom and hissing curses.
1000 metres.
"I'm sorry, Luna."
"You're not sorry!"
800 metres.
"I am, though. And I'll miss you."
600 metres.
Luna became panicked, kicking at Tia's belly in a vain attempt to slow them down.
400 metres.
"Let us go, fool!"
"I can't!"
200 metres.
"You can!"
"I'm going too fast, Luna. I couldn't stop if I wanted to."
The dark mare tried to teleport, only to realize that Celestia had touched their horns together and blocked magic.
"FOOL!"
Impact.
The dust flew out on all sides, followed by huge clumps of grass and earth, stones and a small bushes. When it all settled, a single Alicorn tried to stand.
"Oh, Equestria, no..." she breathed, seeing her ivory horn jabbed straight through her sister's skull. No blood oozed from the wound, and her sister was still as stone.
The white Princess bucked and pulled against the corpse holding her hostage, crying and screaming. She pushed on the skull with her hooves, tried lifting the entire body off the ground, smashed the bone around her horn.
All the while, she cried and cried and cried, depression wrenching at her heart as she demolished her dead sister's face.
"Get away from us!" Luna yelled, dismantled mouth gaping spectrally as she stood up. Her eyes focused, their depths returning to pure white. Celestia screamed as her sister kicked up at her chest, lauching her away and tearing her horn free with a bloody spray.
The Lunar Princess got to her broken hooves as Celestia did the same. Luna shook her head a few times, aligning the bone shards as best she could. There was still a hole in her head, and her jaw swung to the left, but she was standing.
"How could you-"
"We aren't dead, sister!" It yelled, horn darkening the air around it as the bones impossibly knitted back together. The jaw finally realigned, with a nauseating crunch. "Far from it!"
Celestia landed back on her rump, her hooves sliding on the grass as she attempted to escape backwards. "This can't be right! What's going on?!"
"You're pathetic."
"You're dead!" The Mare of the Sun retaliated. "How are you one to judge?"
The thing shook it's head slowly, marble eyes never leaving the pale figure. "That is where you have made your mistake. Alicorns cannot be killed by one another, remember? That is why we always lived through the great wars."
"So...?"
"No mater how much of my body you had... destroyed... it would have come back, in some way or another."
"How can you kill me?" Celestia was beginning to doubt the flaunting of power.
"This thing," Luna lifted a hoof, waving it so the short black fur ruffled, "the darkness, has encased every inch of our being in a shell of shadows. You cannot damage us once your hooves hit our bones, but our own touch will not end you. The shadow's touch is what will."
Celestia paled - it was subtle - and took another few skids back. The black Alicorn simply followed, patiently waiting for the Sun Goddess to trap herself.
"I cannot believe you were too stupid to see the signs. Really, did you think that all those times I used the Nightmare were accidents? With the most idiotic reasons, too. Come on, the bath water got cold? The rain cloud blocks my view of the moon? Rain Drizzle burnt the pancakes? Somepony unfriended me on Hornbook? You must be joking."
"They seemed like good answers to me..." Celestia spread her magic invisibly, looking, searching for something to use as a weapon. She just needed a little more time...
"I guess you didn't live up to the Trollestia title, then."
There. Underground, but... powerful. She could use those. Six... six telekinetic tendrils wrapped around the rocks and started the tedious pull to the surface.
"So many ponies were relying on you. How 'bout Molestia? Done anything to accomplish that?"
Celestia tried her hardest to keep the strain out of her voice. "Not that I know of."
"You look sweaty. You keep those hooves where I can see them." Luna narrowed her white eyes accusingly. "Or I'll tell the entire kingdom which false title you want."
She obediently stuck all four of her hooves in front of her, wincing as one of the tiny stones collided with a larger one. "Okay..."
"You look like a mess." Luna observed, lifting one eyebrow. "What are you plan- HORSE-APPLES how long have you been doing that?!"
Celestia suppressed a snicker at the black Alicorn's shocked wide eyes. The creature glared at her, striking out with her mane to smash a painful blow across Celestia's cheek. Celestia choked as blood surged through her mouth. She felt a tiny cube floating in her mouth, and realized that this thing had actually harmed her. Stones forgotten, she stood up, spitting the tooth out and facing her sister.
Luna laughed humorlessly, tilting her head and easily drawing Celestia's six targets from the ground in small plumes of dirt. "You were working so hard to get these? Dragon fodder?" She waved the stones around curiously, before throwing them over her back, into the distance. "You surprise me, 'Tia. I really thought you would have come up with a better plan."
"I planned more than you."
"We can and will bet your life on the fact that you just lied." The Alicorn narrowed her eyes. "Lying to us is not a good idea."
"Fine. Be like that."
At the sight of Celestia's upturned muzzle and quick one-hundred-eighty rotation, the beast flared with anger. "YOU DO NOT TURN YOUR BACK ON US!"
Celestia was silent and still.
"You will be injured deeply if you do not face us immediately!"
Nothing.
"...Please?"
The Sun Goddess let out a sharp whimper. That voice was Luna, Luna all through, the same voice...
The same voice she had when their parents died...
Celestia spun, wings open and teeth bared, snorting in rage. The black monstrosity looked momentarily shocked, before resuming it's proud aura.
"This voice is not one you adore?"
Celestia shifted on her hooves, biting her lip.
"I should have tried this earlier!"
The creature was jovial, the innocent voice of a better time easily flowing from a fanged, shadowy mouth.
"You..."
"Yes?"
"YOU DO NOT USE THE VOICE OF MY SISTER TO ME!"
The creature was flattened under the sheer volume of Celestia's voice, letting out a tiny squeak and pulling it's head under it's wings.
"YOU SHALL NOT SPEAK IN HER TONGUES WHILE YOU ARE IN MY PRESENCE!"
Her hooves slammed into the ground with every syllable, getting dangerously close to crushing the mare's nose. She drew back with a squeak.
"Okay... OKAY!" It yelled in terror, scooting away from the rampaging hooves, despite not being harmed by them. "I won't use the voice! I swear!"
Celestia stopped, eyes wild and breathing heavily. "You... will... never... use... my... sister... against... me..."
"Fine. But I won't let you raise the sun, either."
Celestia shook her head, still regaining her breath. "No... I can't let you... do that."
"What say do you have?"
She suddenly walked closer, her muzzle mere centimeters from the dark mare's. Her deep blue eyes glazed into the blank white ones. The second Alicorn winced a little with the violation of personal space, but didn't dare run.
"Luna... I know you can hear me. I know you can. And... I'm sorry. I know that you helped this thing take over. And whatever happens... I forgive you. For fighting, for ignoring you... for not listening to you about the night. And... I'll miss you. But I had to do this. Please, forgive me for what I have to do."
With her face blocking the dark Alicorn's view, Celestia had retrieved the stones from the grand distance Luna had thrown them. When she stepped back, golden tears running down her face, Luna saw the six shining stones.
"What have you-"
"Goodbye, Luna." The white princess interrupted with a whisper.
Her horn lit as she send out a magical chime. With a startling intensity, the stones rang back, the air around them distorting with their power. Celestia felt the power swell inside her, knowing it was turning her eyes into pale cinders. The stones began circling around her, a wide ring that seemed to begin glowing as the gems spun faster.
Purple.
Yellow.
White.
Orange.
Blue.
Pink.
Somehow, the colors blended, turning into a rainbow blur before shooting a single arc up from behind the princess and leaping past her to hit the shadowy creature head on.
"NO! NO NO NO NO no no no .. .. .. .."
It's cries died away with the rainbow, Celestia slowly opening her eyes, expecting to see her sister, pure and young, lying on the ground.
There was nothing.
The solar princess lifted her head, on some instinctual urge, the shining moon reflecting in her eyes.
On the surface, a series of craters reared in the shape of an Alicorn's graceful head.
-----
The creature lifted it's head, snorting in confusion. "What... happened?"
Scanning it's surroundings, it lay dumbly, the truth only dawning on it as the sun rose around the edge of a planet she used to call home.
"Goodbye, Celestia."
Luna surged past the shadowy being, raising her voice in futile song, hoping her sister could hear her.
"Where are you, sister?
I'm so alone here...
Where are you, sister?
The moon's colder when you're near
I miss you, sister
Your laugh is lost to me know
I miss you, sister
Is now quiet, what once was loud
Come find me, sister
Can’t I come home soon?
Come find me, sister
Only a thousand years left to mourn
Come here sister, dear sweet sister
Let me see your smiling face-"
The Nightmare reclaimed her once again, taunting her with the song.
"Come here sister, dear sweet sister
And I will make you take my place
Your sister needs you, Princess
Heed her call and come
Your sister needs you, Princess
Let me finish what I’ve begun
Goodnight, my dear sister
You’ll be raising the night soon
Remember, my dear sister
I’ll return as Nightmare Moon"
"I'll return as Nightmare Moon..."