Rarity opened her eyes and slowly stood up. At least she thought she did. If it weren’t for the fact that she could just barely see the outline of the hoof she waved in front of her face, she would have sworn that her eyes were still closed. Around her was nothingness. No cores, no Crystal Throne Room, and no messy workshop in the Boutique. She experimentally lifted her hoof and tapped against the ground, frowning when she heard nothing. It was like tapping against air.
“...arity?” The Empress’ ears twitched in the direction of a wispy call. Panic threatened to overtake what was left of her senses until she heard the faint voice again. “Rarity? Can… hear me?”
“Applejack?!” she shouted, turning to trot towards the voice. It was an odd feeling, like trying to walk along a murky lake bottom. In addition to her sluggish muscles, her senses felt dulled. She knew it was Applejack calling out to her. She could sense the other mare nearby and yet somehow far way. “Applejack! Darling! Can you—”
“Rar... danger... Don’t listen t...” The voice cut out once more, only this time she could no longer sense her dear old friend, as if some sort of wall had been placed between them. And yet stretching out her hoof to tap where she thought the wall was yielded no result. The space all around her was still as vast and empty as it had been before Applejack’s curious warning.
"Fantastic,” grumbled the Empress as she looked around for anything to help her. “This isn’t how a lady is suppose to be treated on her birthday." Although the remark had been directed to nopony, a soft, yet deep laugh echoed through the darkness around her.
"And how would one be treated on her birthday?" mocked a new voice. "With Parties and Parades? Gifts and Glory, perhaps?"
"Who’s there?" shouted Rarity, her horn glowing bright with power as a shield knitted over her. "Show yourself!"
"My dearest Empress," chided the voice as a grey mist began to swirl around her shield. “That is an excellent question. But before I answer it, perhaps you’ll hear me out for but a moment?"
"And why would I do that?" challenged the Empress.
"Because the fate of your Empire and all your ponies, depends on it."
"In case you haven't noticed, I don't take well to threats."
"Oh, I have," chuckled the voice. As it spoke, the smoke began to shift and swirl, revealing Blueblood’s terrified face, floating before her. The image changed again, and soon the frightened faces of many others who had been caught in the crosshairs of her wrath danced around her blue shield. "Regardless, I haven’t come to make idle threats, no. I have come to warn you and offer my aid."
For a moment, Rarity felt the illusory wall between her and Applejack come down. "Run, Rarity, run!" came Applejack’s frantic plea. But before Rarity could respond, the wall came back, leaving her alone with the smoke once more.
"Well, you have a very curious way of doing that," Rarity said as she tried to peer beyond the grey smoke for any signs of the speaker. Every so often, she could feel the smoke solidify and press in against the shield, causing it to burn brighter in those spots. Rarity frowned, knowing that it was testing her strength. Her resolve. "Why should I trust anything you have to say if you will not come forth?"
"Very well, Empress," sighed the gravelly voice. "I can see we aren’t getting anywhere like this and time is of the essence. If a face will provide the comfort you need to hear me out, it shall be done."
The smoke before the unicorn parted to reveal a very familiar draconequus drinking what smelled like sherry and sitting on what looked like her throne.
“Discord?!” demanded Rarity as she took a step forward, her horn crackling with magic. “You’re behind al—”
“No, no, my dear lady,” interrupted the draconequus as he stood up. Something was wrong with his voice, as if he and another were trying to talk at the same time. A single snap of his lion paw, and the chair disappeared. “Although I am a big fan of his work, I’m not the God of Chaos. You wanted a face to talk to and I provided one... You don't like it?" asked the false Discord as he noticed her frown.
"If you were hoping to take a form that would give me comfort, you've chosen quite poorly, I'm afraid. Couldn’t you manifest as something less insufferable? A room full of gassy mimes, perhaps?" replied Rarity, thinking of the myriad of troubles Discord had wrought in the past.
"Well," he grinned as he pressed against her shield once more. She noted with some concern how he absentmindedly traced a diamond from Rarity’s cutie mark with his clawed hand. “Let's try a different face. A friendly face."
The darkness consumed the draconequus, preventing Rarity from seeing beyond the grey smoke once more. She tried to ready herself for anything. A duplicitous double perhaps. Or Onyx in his dashing dress uniform. Maybe it would be a sodden Sapphire, here to sing her another alcohol-infused birthday song. The unknown devil may pull at her heart strings with her own little Sweetie Belle, again.
But what eventually came out caught her off guard.
"What do you think of this?" came the familiar, intelligent voice of a mare. The voice was not alone, just as it wasn’t Discord’s voice alone that spoke before. Rarity took a step back as the tall figure strode in from the darkness on four legs instead of Discord’s awkward two legged gait.
The being that stood smirking before her was the spitting image, right down to the lavender wings, the golden crown, and the dark ethereal mane, of Princess Twilight Sparkle. The false alicorn let out a curt laugh at the Empress’ dumbstruck look. “Yes, I think this works perfectly.”
"T- Twilight? Is it really you?"
"No, of course not," chided the purple impostor. "You wanted a face to talk to and I provided one. Is Princess Twilight not to your liking?" the synchronized voices asked slyly, as Twilight’s countenance took on a look of mock hurt.
"What do you want from me?" snapped the Empress as she shook her head to keep her focus.
“For you to hear me out.”
Rarity stomped a hoof and leveled her gaze at the creature that looked like her oldest friend left in the world. "Alright, enough games whoever you are. You said you wanted to help me? Okay, I'm listening. You've got three minutes."
"I know you, Rarity. I know what you want. I know what you crave. I know what haunts your dreams," it whispered uncannily with its two voices, pressing up against the shield. "All I want from you is to use my power and take what you want. Make your dreams come true. Make your Empire strong and prosperous. Fulfill the destiny of the Crystal Empire!”
“Rarity,” came Applejack’s insistent voice from beyond once more, “I know a liar when I hear one, don’t liste—!”
Something shimmered into existence behind the the false Twilight and floated between the two of them. When she got a better look at it, Rarity’s jaw dropped. It was a scale replica of the Imperial Capital. Not as it was now, no, but as she dreamed it could be.
Towers of perfect crystal and stone stood tall and proud, each building more beautiful and elegant in its design than the last. Aqueduct systems lined whole expanses of the tower-filled city. There were stunning parks and shimmering lakes with fountains. The tableau was truly artistic and yet undeniably utilitarian. And there, at the center of it all, was the capital’s crown jewel. The Imperial Palace. Her palace.
It stood majestically with its modern Gothic inspiration, mimicking the arrangement of a gargantuan pipe organ. It's foundation curved slightly, opening outwards to the South, facing the main gate. From this grand foundation, three legs of tightly packed crystal pillars sprung up and in towards a central meeting point, forming a three-sided pyramid. Where they met, a collar was formed, setting the base of the largest tower in the city.
Dimly, Rarity became aware of breathing on her neck, and the bizarrely synchronized voices called out from the all-too-close illusion of Twilight once more. “It’s beautiful, is it not? But perhaps this is too much, yes? Perhaps you yearn for simplicity? For a return to what was?”
The Crystal Empire vanished before her eyes, and a new scene solidified, revealing a familiar lane in a familiar town. The town of Ponyville. There, at the end of the lane, was the Carousel Boutique. Her boutique.
Rarity felt her knees shake, and her rump fell quietly to the floor. There, just off to the left of the bay window in her kitchen, was a sandbox. A pair of foals, a filly with her eyes and a colt with her mane, were in the midst of a fit of frenetic giggles. Rarity watched numbly as a dull ache pounded away in her chest.
“Oh, Rarity,” the linked voices whispered into her ear sympathetically. “I know your hooves are just aching for the feel of your sewing machine. And your heart aches too. It aches for what you alone can’t obtain. What a shame.” The Empress was so enchanted by the image before her eyes, the image that betrayed her heart’s desire, that she had failed to realize her magical shield was no more.
“I won’t offer again. Will you use my power, and take control of your destiny?”
"Your...your power?" she asked in a hungry whisper, still watching the foals at play. They were roaring, stomping, and squealing with delight through a sandbox city of empty milk cartons and old cans.
“Consarn it girl, will you ju—"
“Yes,” hissed Twilight as she draped a wing over Rarity and pulled her in close. “With my power you can make these dreams a reality. But why stop there? If you’re going to dream Empress,” the two voices purred deviously, "dream big."
Once more the image in the smoke faded into nothingness. Rarity reached out desperately to stop it from happening, but to no avail. All she could do was watch and whimper as the two little ponies and their sandbox winked out of existence.
What came next was a scene that struck her with dread and, curiously enough, a measure of grim delight.
Ponyville’s greens and browns were replaced with sundered marble and the glow of cooling embers. As the vision solidified, she realized she was staring down into the ruined inner chamber of the House of Commons, one of the two bodies making up the Equestrian Senate, the other being the Noble House. It was these two houses that embodied the political will of Equestria now. With Princess Cadence and Twilight being more or less figureheads, the two Princesses had less political power than their predecessors ever did.
There, marching with her head held high, moved the conquering form of the Crystal Empress herself. Resplendent in her armor, she watched her tiny doppelganger stride triumphantly into the middle of the Senate chambers’ replica. The elite members of her Diamond Force flanked her double. Equestria’s cowardly senators bowed before her, and her banner danced courageously atop the pole held by her standard bearer.
Rarity realized that she was smiling as she watched the scene unfold. Suddenly, the small vignette in the grey smoke grew and wrapped all around her. She could feel the broken wood and chipped marble beneath her hooves. She could hear the chants of the ponies calling out her name from beyond the Senate’s walls.
In a blink, the Rarity of her vision faded away, leaving her in the apparition’s wake. She was now the armor clad Empress. The conqueror. Overwhelmed with euphoria, Rarity felt her heart surge in her chest. Victory! This was victory for the Crystal Empire over those who would see it robbed of its glory. A hoof reached out and tapped her on the shoulder. She turned to look, and saw the armored form of Major Tom.
He was smiling at her, grinning really. There was joy in his expression, and conquest in his eyes. Before she could say anything to him, he passed over her war banner. She laughed, a small hauty thing, and took it from him. It shimmered and sailed through the air in her blue aura, before slamming the business end of her standard into the floor in the true center of the room, cracking the marble with thunderous refrain.
All around her, and indeed all the world over, her crystal ponies were cheering and stomping their hooves for her. Victory had come at last.
Rarity’s smile faltered though as she looked at the faces within the cheering crowd. As her euphoria waned, she realized there was something not right. It was almost as she envisioned it, but there were faces missing. Familiar faces. “Where are my friends?” she asked quietly under the roaring din of the crowd. “Where’s Commander Onyx? Or Lady Sapphire? T-Twilight?”
A weight began to form in her stomach, pulling her down to the floor. Once more she asked, “Where are my friends?”
A singular chuckle was her response. Gone was the assurance of Twilight’s voice that softened the edge of the otherwise foul darkness. The scene before her slowed to a stop, and all the color faded out from her vision, leaving only grey figures against the void. “Surely,” it mocked her chiddingly, “you don’t think greatness comes without a cost, do you?”
“A cost?”
“Yes, Empress, everything has a price,” spoke the coiled voice, ready to strike. “And for your dreams to come true, for the crystal ponies’ fate to be secured, that price must be paid in blood.”
“But I-I couldn’t, I wouldn’t... Not to Twilight!” Rarity shouted into the unmoving faces of the frozen figures around her.
“Rarity, Rarity, Rarity,” mocked the voice as if she were still an overeager filly out to get her cutie mark. “So quickly you have forgotten the final signature in the bill Blueblood showed you. Do you think that Princess Twilight the Planner, Princess Twilight the Schemer, will suffer the Empire to be a threat? Already she works to stifle your grand designs.”
The grey smoke swirled around Rarity again, and the vision of victory vanished, revealing a new scene. One where she once more had the starring role, but the stage was set in the Crystal Palace. And everything felt wrong.
The floors were unnaturally dull and dusty. The crystalline walls held a spider web of jagged cracks. Her tapestries hung in tatters, and the sulfurous sting of smoke assailed her eyes and throat.
“Look,” beckoned the voice. The scene spun before her eyes, out into the streets of the once vibrant city. It was nearly as depressing as her dream island. The crystal ponies shuffled about with their heads hung low and their coats dull. The somber air reminded Rarity of her first encounter with them when the Empire returned from its exile hundreds of years ago. Only this time instead of the threat of ancient evil, on every street corner stood the stoic faces and gilded armor of the Equestrian Guard.
“Look,” commanded the voice once more. Rarity blinked, and discovered that she stood in a cavern, far below the Crystal Palace. An old cavern that she had never seen before, with ancient pockets of gleaming stone around an underground lake.
Rarity felt something cold wrap around her neck and tighten, like a collar made of ice. It pulled, and she walked where it led her out onto the lake. Out onto the small island that stood alone in its center. An island with a single purple occupant.
As she walked closer at the beckoning of the leash around her neck, she saw that it was Princess Twilight facing a rather peculiar luminous green stone, panting softly in her armor. Or rather, what was left of it. She’d never seen it in such a sorry state. Rarity looked up into her friend’s face and was shocked at what she saw.
Lines, twisted in anger, pain, and grief, marked her face, making her look so very, very old. It hurt to see her usually calm and regularly joyful friend like this. Rarity always could read her like a book and she was surprised by the determination etched into her face. Sadness as well. But the most telling was the regret.
“What’s wrong,” asked Rarity, watching her friend try and fail to calm herself with a breathing exercise. “What’s happened?”
“Look!” demanded the voice, as the ethereal collar around her neck yanked her beyond Twilight, face to face with a mangled form trapped in the green rock.
Shocked as she was, Rarity tried to jerk herself away from the sight, but her collar held steadfast. Instead she stared on in silent horror at the pathetic wretch frozen in crystal. At herself.
It’s me, she thought numbly. And indeed it was her, encased in the green spire and secured tightly with chains that pulsed with purple runes. Much of her lower body had been blasted away, and the rest of her was scarred. The eyes of her shattered doppelganger in the rock burned with white fire. Rarity knew the being before her was still alive, somehow. Alive and suffering with a rage she could feel welling up in her own chest.
“Wha—”
“If you don’t use my power, there will still be a battle. A battle you will lose,” spoke the voice. “Princess Twilight, unwilling to bear the passing of another old friend, or the genocide of an entire race, will imprison you.”
“For how long?” she asked, rubbing a hoof on the green surface of her potential prison.
“For as long as the Sun shines.”
“Is there no other way?” she asked the voice. Silent heartbeats passed like hours, and Rarity found herself fearful of being left alone with the ghosts of a mourning Twilight and her mangled self.
“There isn’t,” came the oddly sympathetic reply. “Use my power, Empress. Use it and save your ponies. Use it and save yourself.”
“I see,” she said with a nod. For a moment, she looked between the two figures before her, before settling on Twilight with a sad smile. "I'm afraid I'll have to pass, but thank you ever so much for your generous offer."
"Fool!" boomed the voice from Twilight's mouth.
"Idiot!" raged the voice again, from the broken maw of her damaged other in the green gem.
“Idiot?” balked the Empress.
“Yes,” hissed Twilight, as she turned from the green spire, her gaze now boring into the Crystal Empress. “Here was everything, everything you could ever dream. Everything you could ever want. All you had to do was reach your hoof out and take it!”
The darkness renewed itself and became a swirling tempest around the unicorn. She could feel its tendrils rake over her icy flesh. Fear and panic worked their slithering way to the front of Rarity's mind, but the darkness and the enticements held her fast.
"Just give it up, Rarity,” commanded the false Twilight.
“Give up,” pleaded her broken reflection in the green gem.
For an instant, panic won out and the darkness pressed in, drowning the Empress in a sea of black.
"No,” said a voice quietly against the howling madness.
A flash erupted around the Empress, driving back the raging darkness. She looked up as ice began to form on her coat, coalescing into armor unmatched in ponykind. Glaring at the wickedly grinning Twilight, she delivered her proclamation as she broke free of her arcane leash. "No, you foul thing. You wretched worm in the dirt. You will not take me so easily!"
“But I already have you, Rarity,” replied Twilight with a snarl.
The illusion tapped her horn to the ground, and the island in the cave melted away, revealing a blighted hellscape burning in its wake. Fissures of sulfuric smoke spat out of the broken ground at irregular intervals, and the air had the metal tinge to it that Rarity didn’t want to think about.
High in the sky there were no clouds. There was no Moon or Sun or stars. There was only fire.
The darkness that Rarity had driven away now swirled around the maniacally laughing alicorn, and the Empress was not spared the sight of its terrible transformation. Her wings withered to bone until they fell to the ground as ash. The creature’s lavender coat faded into a dusty grey, and its long, billowing mane melted away into a shorter blackened wave.
The eyes burned with the forbidden flames of dark magic.
Disjointedly, the monster shifted in size, shrinking with the awful echo of snapped bone. Pulling more and more of the angry smoke into itself, the being also took on bulk. From its fanged maw, a roar of pain was issued. A roar that changed in tenor and tone to one of primal rage as its horn took on a red glow from within itself before curving sinisterly, like a blade ready to strike.
“King Sombra,” said a disbelieving Rarity as she finished her own transformation into her crystalline armor.
"Pretender!" snarled the fallen King with a snort of fire from his flared nostrils.
“Usurper!” he cried with bitterness and hate dripping off of each syllable.
“Seamstress!” he roared, stamping his forehooves into the illusionary battlefield.
"You’re mine, you insolent mare. All Crystal Ponies. Are. MINE!"
* * *
Luna was no stranger to darkness. As the Princess of the Night, she reveled in it. Often there was a beauty to it, a mysteriousness that brought her comfort and peace as she stalked its depths.
But there was no beauty here, no. Instead, there was a foulness that chilled her, that made her imagination run wild. Something hungry lurked in the shadows. Something dark and ancient.
Something full of hate.
Luna could also feel the Empress somewhere beyond, beset on all sides. The emotions were palpable, lending a taste to the imagined wind that howled across the island of Rarity’s mind. A tinge of bitterness with a coppery finish on her tongue. All the flavors of sorrow, guilt, and a weakening spirit. Simply put, Luna knew that Rarity was running out of time.
Which is why she stepped off the rocky path and ran at a gallop into the murky wilderness. As she ran, the sound of her hooves hitting mud and rock faded, and her legs stretched into a whispy blur. She would take a shortcut.
A route reserved for the Keeper of Dreams.
There were many names for this route, coined by poet and scholar alike; the membranes of consciousness, the pathways behind memories, the road that meets at the intersection of thoughts and feelings. It was simply a space of nonexistence where the borders of the mind could be traversed.
Though the mind was a fickle labyrinth, travel through here wasn’t difficult. Usually. Luna knew that if she just kept her focus she’d reach her destination.
A flash of an ancient memory played out before her. It was Luna in her younger days, when this power was still raw. She had gotten lost once, and just the once.
It took her sister a fortnight to track her down and save her.
She smiled at the memory, but dismissed it all the same, maintaining her focus. A rift opened before her cloudy form. Out of it poured the cool smell of dust and some grey smoke. Not sparing a moment to hesitate, the Moon Goddess dove in, hoping to bring her search for Rarity to an end.
“Stars alive,” said a wide-eyed Luna as she solidified once more on the other side of the rift.
She was standing in a dimly-lit, spacious chamber. In its center stood a raised triangular platform. Three pillars stood in a sort of proud majesty at the intersection of each corner. And atop each pillar was a core.
Three cores, three magical cores primed and set in motion. She looked on in wonder at the unusual sight. True, she’d seen many a core, but never before had she seen three within the same pony.
The way energy flowed along the runic bands as they pulsed with power... and how the three cores would pop and flare with use… There was a kind of musical beauty to it all. Like how windchimes dance on a breeze. Or how the constellations sang to her at night as the solar winds caressed their unseen strings.
From an academic standpoint, this chamber was a treasure trove of data on the nature of magic and mortality. On what it meant to be a pony. Such study was usually the purview of Twilight Sparkle, but Luna was no stranger to the sciences. In fact, she had invented the study of—
A discordant note shrilled through the dusty air, interrupting Luna’s musings. Her ears pinned themselves back and she whinnied against the throbbing pressure in her horn. A pressure that commanded her to yield. She looked around, desperate to find the source of the pain, and caught a glimpse of an angry red glow from a deep fissure in one of the pillars. The one belonging to the cracked core that was actively seeping grey smoke.
Alerted that something was off, the Moon Goddess pushed aside her scholarly thoughts and weaved a protective web of magic around her own mind, protecting her from outside influence. It also had the welcome side effect of stopping the pressure in her horn.
The cores and connecting runes flashed as magic was forcibly pulled along the lines towards the cracked pillar before being violently discharged. Sparks flashed with the angry energy surge, damaging the already visibly stressed bands.
Luna moved closer to inspect the nearest rune band. Some of the runes were darkened out of sequence, and she knew their connection to the host core was lost. This forced the magic to jerk from one active rune sequence to another farther down the band, causing a shower of sparks that flashed like lightning.
Luna wrapped a patch of darkened runes in her own cobalt blue magic, briefly igniting them with restorative energy. She watched as the entire band flickered hopefully for a moment. When the next magical surge rushed through it, she couldn’t help but think that her small effort had been for naught.
Luna released the band with her magic and stepped away. The runes still glowed with her magic for a time, compensating for the ongoing damage the unaligned third core was causing.
“Rarity… If I knew it was this bad...” said Luna, shaking her head in disbelief. She stood in silence for another moment, pondering what next steps to take, when she heard a frustrated cry call out from the darkness beyond a large open doorway that lead out of the chamber.
“Consarn it girl, would ya just listen to me? You’ve gotta get on outta there!” Luna’s ears twitched in the direction of the yelling and slowly circled the triangular platform to get a better view of the doorway.
“Rarity!” shouted the exacerbated voice once more. “Come on, gal!”
The Princess came to a stop as a mare stomped into the chamber from a swirling blackness beyond the doorway. She knew that mare once, or rather the mare that this apparition represented. She was one of the Elements of Harmony. Applejack. Her name was Applejack. It was all clicking for Luna again.
She looked around and carefully stepped over some of the debris that littered the floor around the threshold. Chains and bits of wood by the looks of it.
With a frown, Luna realized that the debris meant that something locked away had burst in.
Applejack reared up on her fore legs and bucked against what Luna assumed to be empty space, but cocked her head in puzzlement as the farmpony’s hooves hit true, causing the darkness to ripple. Ripple like a wall of delicious flan, or perhaps gelatine with chunks of tropical fruit in it, or—
Luna’s stomach called out in the silence. A rumble that ached its way down her empty gut. She sighed with a small headshake. This is what she gets for drinking her breakfast. Brunch. Whatever, the point was she didn’t get a proper meal this mo—
"P-Princess Luna?!" stammered Applejack with a half-bow as she stumbled her way over to the hungry Princess. "Tarnation, am I glad ta see you!"
The farmpony reached her in the space of a few heartbeats and pulled the Moon Goddess into an earnest hug.
"And I, you," said Luna to the mental apparition. "Tell me," she continued as she pulled away from the hug, "what transpired here? Where is our friend?”
“Rarity, she… well, I,” Applejack didn’t even pause for breath as she rattled off to the races, describing the different events the two ponies experienced in Rarity’s subconscious.
Finding a disheveled, barely responsive Rarity in her boutique. The false Sweetie Belle and their trek through the island came out as a blur, and Princess Luna found herself nodding her head to keep up with the other mare’s frantic conversation pace.
“An’ then we found the chamber here’n Rarity got ta fixin’. Everythin’ was aces ‘til she noticed the door over yonder. I tried to tell her ta get away from it, but she didn’t listen. Then the durn thing burst open like a rottin’ apple in the sun an—”
“Shhh, calm yourself Applejack,” said Luna, halting the mare’s ramblings. With a burst of will, she straightened the earth pony’s hat before continuing. “I’ve dealt with the Nightmare before, and I am confident I can free Rarity from its embrace.”
“Nightmare? Whadda ya… Oh, horseapples. Umm, your Highness?” asked Applejack as she sat down to nervously tap her hooves together.
“Just Luna, Applejack,” corrected Luna as she experimentally poked the dark barrier with her mind.
“Right, Luna,” said Applejack. “It’s not the Nightmare. It’s, uh… It’s worse.”
Luna paused in her investigation of the barrier and looked back at the sweating pony. “What do you mean ‘worse’?”
“It’s him.”
“Him?” balked Luna. “Him who? Discord? Tirek?”
Applejack shook her head before uttering the horrible heart of the matter. “It’s King Sombra. Evil King Sombra.”
All thoughts of hunger evaporated from Luna as her stomach dropped out from under her and adrenaline poured through her body. “How? I thought Cadence destroyed him with the Crystal Heart!”
She took a nervous step away from the barrier.
“I dunno the whole truth yer highness, but I figure that the no good varmint musta squirrelled a parta himself away’n the Crystal Heart, er somethin’.”
“But…” whispered Luna as she turned to look with dread at the seeping core upon its cracked pillar, “No,” she said to herself as much as to Applejack.
No. This was no windigo core. It was nothing of the sort. This core was a fragment of the greatest evil ever born on Equestrian soil. It belonged to the greatest tyrant who’d ever lived to enslave another. She knew it with certainty now, as if the name were a spell that removed all pretense of doubt, and dissolved the fuzzy blur of uncertainty that had previously enshrouded the hated sphere.
“Applejack, we need to get in there,” she said, her wings stretching open as she backed away from the barrier.
“I’ve been tryin’ but all the buckin’ in the world ain’t helpin’,” said the other mare with a growl as she galloped after Luna. “If’n you have another idea, I’m all ears.”
"I do have an idea, though it is rather unconventional."
Applejack came to a stop next to Luna and cleared a significant amount of substance from her sinuses before spitting the horrifying contents onto the stone floor with an appetite destroying 'splat'.
"Don't go standin' on convention on my account, yer worshipfulness."
Luna said nothing as she looked back at the barrier. Believing the distance to be enough, she stopped, lowered her head, and gave her tiny rump a little shake. The two mares now stood on the other side of the room, the cores between them and the door.
Using her magic, Luna reached out again and tweaked a few of the rune bands to help her with this next part. Kneeling on her fore legs, she stretched down and looked over at her accomplice.
“Climb on. And don’t pull any feathers.”
Applejack looked at her with wide eyes and an open mouth. Then closed it. Then opened it again. And closed it once more before silently climbing onto the larger pony’s back.
“Hold on. We’re going to ram our way through the barrier,” declared Luna.
Before Applejack could respond, the Moon Goddess shot off like an arrow, straight and true. On the edges of her perception, Luna heard the farmpony hollering something just over her shoulder as they grazed a cobalt blue rune band. The band gave her a boost in speed, and she lowered her head, aiming the business end of her horn at the barrier as magic gathered at its tip. The barrier grew closer and the tip burned brighter.
Just before she hit the rippling surface of the previously impenetrable wall of darkness, Luna closed her eyes and took a deep breath.