Luna... I think you're missing the point.
I'm sorry, Twilight, I know I am. I've been trying hard to understand you, but you just aren't making any sense. It would help if you explained it again.
... Really?
~L~
Luna eyed the ancient portal unsteadily as the stone door creaked open. She turned back to her sister, who gave her a soft smile and gestured for her to enter first.
"You aren't afraid at all, Tia?" Luna asked skeptically.
Celestia trotted up next to Luna, draping a wing over her in comfort. "I have the utmost faith in my student's judgment," she said.
As the two princesses took a few more steps into the passageway, a mystical black aura enveloped the walls beside them, bringing forth a railway of torches. Lighting themselves as soon as they appeared, the torches revealed a long, winding staircase. Celestia looked at her sister quizzically for a moment before shrugging it off and continuing on.
"It's not Twilight I'm worried about..." mumbled Luna under her breath.
~L~
Yes. Really.
...
...
What are you doing?
I'm getting a book.
For what?
You clearly need it.
I'll be fine without the book. Can we just go over the basics again?
Suit yourself.
~L~
A sickeningly familiar feeling overtook Luna as she and her counterpart proceeded down the stairwell. It was clear to her what the consequences were should she fail, so she didn't even want to consider it a possibility. Unfortunately, the dark thoughts were imminent.
Lost within her own mind, Luna tripped over herself, nearly tumbling down the passageway as a result. Standing herself upright, she rose only to be met with violet eyes, concern overflowing from them.
"Lu, what's wrong?" asked Celestia.
"Nothing," she said, dusting off her hooves. "I just wasn't paying attention."
"You're a terrible liar."
Luna laughed sardonically, ruffling her wings before walking again at a slower, more cautious pace. "I know," she said. She swallowed hard, taking a moment to stand still on the stairs. She looked at her left hoof -- which was now trickling with blood -- and sighed, letting the weight of everything fall upon her shoulders. It was an accepting sigh. A sigh that was partially the reason why they were both here. Celestia shot Luna another concerned look, but she simply ignored it.
~L~
Magic comes from within yourself. It is an extension of your influence, your personality, your emotions. It is, in the truest sense, you.
So what does that have to do with control?
To master your own abilities, you need to find peace with yourself. You need to understand and face your fears, desires, insecurities, faults, and strengths. You need to know what you love, what you hate, and accept that you do. Your judgment cannot be clouded by any of these – you must use your emotions to guide your magic, not send it on a rampage.
... Care to simplify that?
Clarity.
Clarity?
Yes. The key to magic is clarity. If your mind is clear, you can see. You can see everything from the moon and the stars to the smallest rat-flea sitting on a blade of grass. It is imperfect perfection, the absolute of all that magic is or ever has been. We would like to believe that emotion is what drives our magic. Don't get me wrong: occasionally, it does. But the way it drives our magic is why it cannot be thought of as a dependable source. Emotion is a flame without guidance nor constraint. It expands and contracts with force unimaginable. If you aren't careful, all control can be lost like a kindred spirit setting your soul on fire. That's why you couldn't handle Nightmare Moon the first time. Your mind was fixated on jealousy and hatred. It's what made you lose yourself. If you ever want to have hope at trying again, you're going to need to answer the big questions: Who are you? Why are you here?
Not all things are easy to clean up. Some stains are just too deep.
~L~
"You can tell me anything, Lu," said Celestia, closely following her sister. "You know that I would never hold anything against you."
"If only that policy existed a millennium ago," Luna retorted, coming across more spitefully than she had intended.
"I..."
"I'm sorry, Tia. I didn't mean that. You did what you had to," reassured Luna, turning back to give Celestia a quick nuzzle before continuing on. "It's you doing what you have to again that haunts me."
Celestia stopped dead in her tracks. "You can't be serious."
"I am," Luna began, although somewhat unsure of how to word what she had planned to say next. "You didn't tell any of Twilight's friends about this ceremony, much less invite them to supervise it. If something goes wrong, then you must use the elements by yourself, and we both remember exactly how they respond to you."
Celestia turned away in shock. "I would have tripped," she finally said.
"What?"
"If I had that to think about again, I would have tripped too," she said, still unable to meet her sister's curious gaze.
~L~
Luna... Why do you want this?
What do you mean?
Are you not happy? Why would you be willing to risk everything, just to gain what once destroyed you? What could possibly—
I'm useless.
... What?
I'm useless, Twilight. Every single day, I watch my own sister crack under the pressure of leading my country. She could not raise the sun for weeks after her bout with Discord, and I did nothing to help her. I wouldn't have been helpful anyways.
Princess...
Don't. This is something I need to do, and it is a risk worth taking.
So that's a no.
A no?
You're not happy.
~L~
Luna reviewed her surroundings warily as she stepped down from the staircase. Without warning, an electric blue aura formed at the tip of her horn, gracefully drifting upwards as it illuminated the otherwise black cavern. Celestia watched her sister perform the spell in awe before turning to look at what she was lighting up.
Her mouth fell open.
Before her was an enormous underground colosseum, the walls lined with books, scrolls, and various scientific instruments. On the floor was an entire laboratory, filled with incomplete experiments, desks, and wires.
"Lu... What is this place?" she asked breathlessly.
Luna grinned maniacally, levitating an old beaker to her muzzle in order to examine its ancient contents. "This, my glorious sister, is my study."
"You never told me that you-"
"Abby!"
Luna spread her wings, flying forward with all her might before coming face to face with an old, average looking abacus. "Oh, how I've missed you!" she announced delightfully. The abacus in turn had nothing to say.
Celestia failed to stifle a giggle as she trotted casually over to her little sister. "Luna, this place is amazing," she said once Luna had finished pointlessly moving beads back and forth. "I had no idea you constructed something like this."
"It took awhile," she replied modestly. "But it was worth it in the end. A thousand years, and nothing has changed. Oh, the nostalgia of it all."
Luna swallowed a lump in her throat as she looked toward the center of the colosseum. On a silver podium stood a jet black mannequin, dressed in unscathed cobalt armor.
Following her sister's gaze, Celestia raised an eyebrow as she looked over the armor. "It's just like new," she said, confused. "But how? Wasn't it destroyed when Twilight and her friends used the Elements of Harmony to free you from Nightmare Moon?"
Luna chuckled softly. "It's just armor. I made a few spare sets."
"... No sinister magic or evil enchantment making the armor invincible?"
"Boring, isn't it?" asked Luna, continuing to laugh as she spoke.
"No," corrected Celestia. "Just... out of character."
~L~
No. No I'm not.
Me, Princess Celestia... We all love you so much. This isn't the solution.
I wish I agreed with you.
So what if she has a workload? She wouldn't want this. She wouldn't want you to risk hurting yourself. You're more important to her – to all of us – than a few stressful days. I really don't want you to go through with it.
It's not just about that.
Then what?
I need to do this. For myself.
... Huh?
I live a failure, Twilight Sparkle. Everything I have ever done has been in vain. My name is slurred, and even those I hold dear have always been disappointed with me in some way. I need to take my life back. I need success. Otherwise, I don't see what purpose I have to live. Imagine what it would be like for you if you were to never pass your entrance exam into Celestia's school. If you were to never even meet my sister. Never find any friends. Never meet Spike. Die alone in a pile of books with nothing to your name. But that didn't happen, the universe willed it not to. The Elements themselves willed it not to, and if you try to deny that, you are a liar. I feel as if I am being willed towards this. I must act now, lest I permanently obliterate the little I have left.
...
...
... Thank you, Twilight.
I thought you needed that.
I did.
So there's no way to stop this?
Correct.
Then I'm coming with you. I don't want you to be alone. I won't let that happen.
... No.
~L~
"Help me clear out a space," said Luna, looking over the laboratory in thought. "I don't want to break anything."
Celestia nodded as a golden aura wrapped around various desks and materials, carefully moving them off to the side. She and Luna worked quickly and easily, but a trickle of sweat still fell down Celestia's forehead.
"Luna?" she called out.
Luna turned to her sister, dropping a chair accidentally in the process. "Yes, Tia?"
"You were right: I am scared."
Ignoring the cluttered stadium before her, Luna fluttered towards Celestia, who before now had been encouraging Luna to go through with the ceremony. "Of what?"
“I... I can't lose you. Not again. I don't know what I'd do if...”
Luna brought a hoof to Celestia's head, stroking her mane gently. “I promise you, it will be alright. Let's get this over with.”
“Right now?” Celestia asked, confused.
“Nothing in here is that important. Worst case scenario, I burn some of my notes,” Luna replied, shrugging as she looked around the room.
Celestia nodded slowly. “I believe you know what to do better than I would.”
~L~
What? Why not?
You are like a sister to me, Twilight. If I fail, you...
I what?
You could die. I could kill you.
...
...
You're really doing this, aren't you? You... you're... I can't even believe...
Reality just sink in, eh?
How can you speak about it so lightly?
I've had my fair share of time to think over the alternatives. They aren't pretty.
If you don't want me to go with you, I’ll accept that. But I don't want you to be alone. Please, bring Princess Celestia. For me. I know she can handle herself.
I was already planning on doing that.
... You were?
Yes.
Why?
If something goes wrong, then action must be taken.
You're talking about...
Yes. I am.
Princess...
It won't happen.
~L~
A gust of wind blew throughout the colosseum as Luna readied herself. The scene of her sister standing focused, centered, and stoic in a dimly lit arena was strangely ominous to Celestia, but she kept those thoughts to herself.
Celestia approached Luna one last time. "Lu, whatever happens... I just want you to know—"
"I love you too, Tia. With all of my heart," she said, her voice cracking as she strained from the concentration.
Nothing left to say, Celestia lightly kissed Luna on her forehead before retreating to a safer distance. "Be strong, my little pony..." she whispered.
Luna stretched out her wings and knelt down, a few small sparks of lightning shooting from her horn as she did, though no aura or light was visible.
Clarity.
Luna looked inside herself, and what she saw was more than a little frightening. She tried to take a deep breath, but unfortunately, that wasn't enough to keep her seed of doubt from spreading. Luna writhed in agony as visions of terrific phantoms shot into her with the force of a dragon's flame. Her mind lit on fire, her bones began to crack under the pressure, and her eyes slammed shut. But in that moment of blindness had she been able to see the most.
"You have returned to me with haste," said a voice, screeching horrendously like a knife on a chalkboard. "I would have given you more time. What is it that you seek?"
"I seek to claim what is mine," answered Luna.
"Claim what is yours?" the voice asked. "You mean ask to use what is ours. If you think you can come here and make demands, you have miscalculated. You're weak."
"No," said Luna, shaking her head vigourously. "You miscalculated. I am smarter than I was. When I called upon you, Nightmare, I wanted the moon to be eternal. I wanted the night to last forever. It's an ironic twist of fate, isn't it? The Elements like to work in torturous ways; however, the kind of torture inflicted upon you is a lesson. At first, I didn't get it. I thought that I was sent to the moon to be punished. To be isolated away from my citizens. But that wasn't it at all. No, It was something much more important. Only now have I truly come to realize what I was meant to figure out a thousand years ago."
"And what would that be, dear?" asked Nightmare Moon.
"The night does last forever—even if we can't always see it. You have nothing to give. You have no power over me. I'm taking back whats mine."
Luna swallowed her negative thoughts, opening her eyes as the black world around her suddenly came into view. It was a new perspective, the technicolor of life. The nightmare vanished, leaving only one emotion to stand champion among them all: love. She looked at the love she had for Twilight and her friends. She looked at the love for her family. Cadence, Shining Armor, and even Blueblood. She looked at the love for her sister, and through her reverie, smiled.
She wouldn't fail.
Plumes of smoke rose and spiraled around Luna as she poured more energy into the spell. Upon noticing this, she felt a burning sensation in her eyes and on her flank. Looking back at her tail, she saw the black cloud surrounding her cutie mark grow outwards, spreading throughout her entire body.
Unable to bear it anymore, she slammed her eyes shut in pain. When she reopened them, they were no longer equine. They were more draconian, with a hint of deeper turquoise.
Next came the armor. From its place on the mannequin, the helmet and boots were floated over by a black aura, flawlessly fitting onto the changing body of Luna.
Luna would never forget what came next. In her mind, every single moment of pain she had ever experienced flashed before her eyes. She relived every time she had felt ignored or unloved, every time she had been alone. Every time the stars had been seen by nopony at all. She felt the dark essence of Nightmare Moon seep into her thoughts, infecting her mind.
Electric sparks flowing from her horn, Luna began to create what would become an intense lightning bolt. She closed her eyes, focusing as she released her magical grip on the lightning bolt. It shot outwards at first, but turned shortly thereafter.
Directly at Luna.
Luna collapsed from excruciating pain as she ripped the spirit from her, destroying its very being. Her ears rang with a high pitched scream that came from everywhere at once. The sensation tore mercilessly at Luna, the blinding pain making it impossible to even think. For a second, she thought, death would have been a gift from the heavens had it come at that moment.
Frankly, she couldn't care less.
The true moon princess stood as proudly as she could with shaking hooves as the smoke cleared, revealing a taller, darkened alicorn. Luna stretched out her wings, examining them carefully before an idea came to her.
Focusing on the tip of her horn, Luna sent a small surge of power outwards. Without the slightest delay, a massive crack of lightning shook the entire stadium, making Celestia cringe.
Mesmerized by the scene, Celestia cautiously approached her sister, reaching out a hoof to touch her. "... Luna? Is that you?"
Luna laughed, throwing her hooves around her sister in relief. She held Celestia close, a few tears dripping down her muzzle. After she finished relishing the warm feeling of her sister, she let go, her legs falling back down onto the floor.
"Yes," she began, smiling in genuine joy. "It is me."
Celestia laughed, walking around in a circle as she did a once-over on her sister's new appearance. "You look amazing," she said in awe. "It is as if Nightmare Moon changed; you improved somehow. You look better than you did the first time. More... content."
"Probably because I am," Luna suggested.
"Now what?" Celestia asked, continuing to admire her sister's new-found appearance.
"Now," Luna started, walking over towards the staircase. "We announce it. But first, I have somepony else to tell."
Celestia nodded slowly. For so long, she had been afraid of herself. For so long, had she wanted to forget everything about Nightmare Moon and move on. When she had first taken power from the spirit, it corrupted her. It destroyed her.
But this time, she did not falter.
