There is always time think...
It is not warm, it is not cold, it is an absolutely freezing sensation that pervades her whole being. Ice-cold would be a more merciful atmosphere compared to where she was now.
Atmosphere, she loathed that word now for there was none here.
There was nothing.
She had no body: no eyes to see with, no ears to hear with, and no hooves to walk with. For an unbearably long time, there would be nothing to taste, to hear. All she could do was feel — hate, sorrow, cold, pain, and fear.
It is very dark; that is one thing she knows in here. She can still remember.
She remembers everything so well, which is why everything hurts so much now. She can feel that she is not quite herself; she could feel time passing but not how much.
All it had taken was one spell and everything — all the pent up emotion — was unleashed. The magic was all her own, from her and made by her, but the likes of it had never been seen before. Like the northern king's it was quite clear something happened to her mind, but to what extent?
What would be recorded by the scribes in the coming ages? That she was two? No, that was not so. She was still one goddess hurt and twisted between all those layers of neglect and sadness. Those halves of horror met somewhere in the middle, merging, and bleeding into one another.
She did not even look the same anymore, but it mattered not when she was sealed within this distant and lucent satellite.
She could not see any of that light. Not any more.
This was the closest thing to nothingness she was likely to know.
Discord was petrified by the Elements that they unearthed from the ruins of a much older castle beneath their own dwelling in the Everfree, and in doing so, they had rediscovered the World Tree. Before they found those sacred stones and their once-friend had his last laugh, there was another sealed in a stranger place, but they had used their own magic for that — and he had more than Discord's last laugh, for an entire city was lost.
That northern waste was a sun-scorched and sand bound desert compared to her here and now, for anything was warmer than the freezing hurt she could feel. This cold never numbed, creating a constant, aching chill.
There was no home here and there had been one in that forest, the ruined castle both Celestia and herself barely had the chance to walk in during their two millennia-long lives. In her divine wrath, she had destroyed the atrocious edifice that replaced the grand old palace they had walked away from together as happy-go-lucky fillies.
There was so much time to think up here in the sky. She could only think since she knew not much else — other then that time was passing as it always did. But what did it matter to an immortal like herself?
It did not.
She cared not that time was passing or what was done what that time because she was alone here, where it did not matter.
After all, she could do nothing but think and ask questions.
Would she be like this forever?
'This', of course, being her not-quite herself transformation, she had snapped after all. That statement was simple even if nothing else was.
She was not even sure if the spell or whatever strange and awesome she performed — as horrifying as it was — could be reversed. She was sure there was regret in there somewhere but not specifically what it was for.
Most of all she was well aware that she could not quite control herself anymore.
Her own thoughts were conjured in brief, angry, and vengeful snaps. The mental bite's wound lingered long after the initial realization. Always, she asked how were these hers? Her bewilderment was never addressed for it there are only questions, there can never be answers.
The resentment never faded and thrived once again in this lightless place.
Nothing was dim for every second of this turmoil occurred within the mind of an immortal where 'fade' is only the slightest possibility, and not as mortals know it, and 'forget' is utterly impossible.
Maybe all the sorrow was for herself; who else would need it?
There was no fire or warmth here. She could not laugh or cry, all was mirthless. However, this stopped nothing — her wrath was more than a mere candle, it was a cold and biting fire that inspired her but never drained. Her bitterness was not wanton or foolish.
From this place, her magic essence would slowly reach out with invisible strings seeking the power she needed, the power that was her birthright. Celestia could not block this gradual occurrence no matter how much she tried if she noticed at all since powers lie elsewhere and who is to say she remembers her all the way up in the sky?
Up here, the daytime of the world below was masked in the sun's light, oblivious to the machinations of the heavens above where all is darkness and the careful workings of the banished princess make no fault as she moves the threads that guide her fate. She uses her currently sealed and finite power to secure her hope of release.
Ever so slowly, it begins, and the stars will aid in her escape at long last.
Author's Note
This chapter here is the original draft. The second part was added later. I suppose that you could just read this one, if you really wanted to... please don't 
...as long as you remain yourself.
Names are important; somewhere inside every creature has something they call themselves, and their truest name hangs within their heart and soul. It is how they fit themselves into a word, a sound to capture their whole self. Such a thing helps forge legacies, for what good is an idol? Without a name, one is in a dysphoric state and lacking a complete identity.
The name could be a word, a mere sound, a memory, or even the feeling of being oneself.
She had a name.
Or, she has... one... two...
Night-Luna!
Lun-mare Moon!
Which is it?
It eludes her as she sits in the sky weaving her key of starlight.
She cannot lose her own name! One of them must be right!
They had meaning, both of them, but only one of them was her.
Only one was right.
If she loses her name, she will lose herself and once you lose yourself you are less than nothing...
Somepony said that to her once. Who were they? Will they still be there? It has been so long.
Will she care?
She has waited so long, she is almost free and now does she risk losing what is most precious to her?
It is like a dream, this limbo. Part of her wished she could dream but she cannot sleep and it has been hard to feel as of late. So there have been no dreams here.
There is only cold. Is that because of her?
But, really how much time has passed? It cannot be too long, surely even a spell such as that could weaken with age, or is her power all the hope she has of ever being set free?
There are two choices. One is right. It should be simple but nothing is ever simple.
Not here.
Which name is first?
Nightmare Moon.
What does it mean?
Wickedness, confidence, laughter, and darkness. That is all she knows of that one; where is the other?
Luna, it is the shorter name, and there is a bitterness to it.
Temper, insight, silence, eccentricity... there should be more.
That really cannot be it, she must remember more!
She cannot, it is too dark and she cannot see anything.
There just has to be more... that is too sparse of an identity, she knows that there has to be more for Luna. Surely somepony cares about Luna? Does nopony remember her?
It is just so hard to tell... and oh, it is been so long...
But now the spell is complete, and in this second she feels the threads of the Element's spell crumble under her own power, which aligned her stars so wonderfully...
...and she still has to pick one.
There just is not enough time to decide! She has waited so long but and at the perfect moment, the one she has been pining for she needs more time?!
No, it simply cannot be. She will have to pick one, at least for now...
In the last seconds before the finalization, she takes another moment of her everlasting life to think.
Laughter sounds nice, so happy. She is sure she remembers happiness, it was nice, was not it?
So she picks the one with laughter and remembers a pink-maned filly laughing alongside the small blue one that must be her, yes, that one is her.
That is happy. Nightmare Moon is happy; that is her choice.
After all, is happiness not what Luna wants?
