Princess Amore stared at the mirror of her room, going through her emotions as she glanced at the open parchment on the table one more time, still not spotting anything that could harm the Crystal Heart. Still, a nagging feeling of doubt still felt heavy in her chest, as she felt anxious about today's experiment.

Today, a single spell would be remembered as the one that saved the Crystal Empire... or the last desperate attempt to save a dying empire.

Letting out a sigh, Princess Amore's horn glowed as the parchment closed itself, levitating behind her as she walked out of her quarters, nodding to the guards and maids outside as she walked through the hallways, distracting herself by glancing at every piece of artwork, decoration and furniture as she headed towards the dining room.

Six decades had nearly passed since she had first founded the Crystal Empire, gathering the scattered crystal pony tribes spread across the frozen north. It had taken a lot of work, but now the empire was a growing beacon of how cooperation and love could conquer even the fiercest of forces, taming the wild nature of the frozen north. Even the modern dukes and ministers still appreciated their humble beginnings, as they were descendants of the old tribe leaders and her first ministers.

She idly wondered if her old friends were proud of her work on the other side.

The guards at the dining hall saluted as Princess Amore opened the doors and stepped in, watching as Glimmer and Thunder were already there, as were Sombra, Radiant and Airy "Good morning, everypony" Princess Amore said, as she took her seat at the head of the table, with gathered ponies (and a fairy) greeting her as the maid took her breakfast order.

Airy flew from her spot on the table, stopping to hover in front of the princess as she set down the parchment on the table "So, how's the spell? Is there anything that needs to be changed or will we finally get to see it at work?" Airy asked, as others too looked curiously at their princess.

Princess Amore smiled at the excited looking fairy "Yes, we'll be casting the spell after breakfast" she answered as Airy cheered, doing a little spin before flying to her seat. The others at the table looked happy too, as they began to eat their breakfast. Princess Amore continued smiling as her own order arrived, enjoying the breakfast as the ponies around the table began planning how they'd celebrate.

Airy hummed to herself as she sat on top of Sombra's hair, watching as the group of unicorns and the lone pegasus exited the castle, walking down the stairs as Princess Amore stopped before the Crystal Heart, nervously glancing at the parchment once more.

Airy stood up before taking flight, leaving Sombra's lush hair as she flew to Princess Amore's side as she turned her head to look at the little fairy.

"You can do this, your highness. Just take a deep breath and slowly let it out, I’ll guide you through the spell" Airy spoke softly in comforting tone as Princess Amore took a deep breath, before letting it out as her nervous behavior disappeared "I am ready" she spoke, as Airy smiled "First, synchronize your breathing to the feel of the Crystal Heart, then think of everything that makes you happy: Family, friends, your subjects.... anything and everything you wish to protect" Airy instructed, as Princess Amore closed her eyes and focused.

"Now, gather your magic in your horn and cast the spell, pushing all that emotion into the spell" Airy instructed, as a beam of magic left the princess' horn, striking the Crystal Heart that began to pulse and spin faster "More, keep going just a little bit longer!" Airy encouraged as Princess Amore began to sweat, before gasping as the spell cut off.

It was at this moment, that the Crystal Heart stopped spinning and a sphere of magic expanded, sweeping over those gathered harmlessly, passing through everyone as it spread across the Crystal Empire, stopping as it reached the barrier.

Airy looked at her shining hand, as she felt a shiver across her body disappear; When the wave of magic had swept over her, it had given her a deep shiver as she felt... something looking into her, only to pass as quickly as it had appeared when it had not found whatever it had been looking for.

Turning her gaze towards the smiling princess, Airy looked at her in amazement as Princess Amore's coat and mane shined too, as if her coat was made of crystals. Turning to at the others, she could see that everyone present also had the shine to them, as Sombra and Radiant hugged each other with happy expressions, as did Glimmer and Thunder.

"It is done... while the exhaustion is not gone; it is more emotional than physical this time: the return of the crystal coats is a good sign" Princess Amore spoke as she turned to others "Captain Thunder. I need you to take flight and inspect whenever the barrier has returned to its former shape" she ordered, as the pegasus untangled himself from his wife's hooves and saluted, before taking flight as he flew from the plaza, before flying up once he was no longer beneath the castle.

"So, this is why your kind are called 'Crystal ponies'" Airy said, as she observed the smiling princess "I thought it was because of the location" Airy finished as Princess Amore shook her head "While many mistake the Crystal Ponies as mere Earth ponies, they are a legitimate subspecies. Yes, most of them are without wings or horns, as Pegasus crystal ponies are rare and Unicorn crystal ponies extremely rare: there have been entire generations when no Unicorns have been born in the Crystal pony tribes" Princess Amore explained, as she turned to look at the other three unicorns "The four of us are only unicorns that remain in the Crystal Empire; there used to be seven more in this generation, but they have since moved on to Equestria, where they now live among the local unicorns" she explained, as Airy nodded in understanding.

It was at this moment that Thunder Shield returned, landing next to Glimmer as he looked at the princess "Unfortunately, it would seem that the barrier remains the same size as before; it has not been restored to its full size" he reported, as Glimmer and others felt their smiles slip away, as Princess Amore placed a hoof at her chin "That spell should have done the trick: the shine of the Crystal ponies has returned, so why hasn't the barrier too?" She wondered aloud, as she thought about it.

To Airy, it was quite obvious as she glanced at the Crystal Heart spin on its pedestal once more; it would appear that it worked like a battery, with Princess Amore's previous use draining it. It was only now that they had cast the spell, that it had its first spark of recharge since... probably forever; the magic alone was not enough to charge it, it seems...

"Maybe the spell is faulty; I'm sure that must be it" Radiant spoke, only to be interrupted as Airy spoke aloud "I think it worked just fine" she said, as the others turned to look at her as she slowly began to fly circles around the Crystal Heart.

"As I understand it, the Crystal Heart seems to work as a container for magic, with the enchantments within providing the effects. For it to have continued to work for six decades, it must have had a lot of magic within. However, it also appears that its original creators somehow managed to gather their emotions into the Crystal Heart as well, hence the shine of your... coats" Airy spoke, stopping as she turned towards the gathered ponies.

"So, while Princess Amore has been supplying it with magic, it has still been drained of its stored emotion; which is why even though the spell worked, there just isn't enough stored happiness and love to keep it active outside of current limits" she paused, as the realization spread among the gathered ponies.

"So even if I cast it daily, the spell will only be able to hold its current power; nopony can provide it with enough emotional energy to restore it back to what it once was" Princess Amore spoke, glancing at her students "And even if Radiant and Sombra were to aid me, it would still take decades, maybe even centuries before the barrier has been restored to its former size" she finished, as Airy flew to her side.

An idea began to form in Airy's head, as she watched Glimmer ponder a moment before she spoke "So... In the end, all we could do was stop the decay of the Crystal Heart" Glimmer said as she lowered her head, feeling sad as Thunder wrapped his hoof around her.... only for a high pitched giggle to turn everyone's gaze to laughing fairy.

"Don't be a silly little foal, Glimmer" Airy said as she flew in front of the very confused mare "It's exactly like Princess Amore said: no singular pony could restore the heart to its fullest. But the Crystal Empire isn't made of only a few ponies, is it?" Airy asked with a smile, as Glimmer answered "Well no, but how could three unicorns restore the Crystal Heart?" she asked, as Airy giggled once more "They aren't alone, you silly mare; the Empire is filled with ponies" she said.

It was Radiant who spoke this time "But how is that going to help us? They cannot cast spells" she said, as Airy flew so she was roughly in middle of the gathered group of ponies "They don't need to; As the Crystals of my home gather the hopes and prayers of the people passively, all we need to do is add an enchantment to the Crystal Heart that does the same. That way...." Airy left the end open, as Princess Amore's eyes widened "The Crystal Heart could gather the love and light of everypony in the Crystal Empire by itself, thus keeping itself powered without outside assistance" She finished, as the gathered ponies also widened their eyes, watching as Princess Amore began to pace.

"The Crystal Heart is connected to the entire city; So as long as the ponies are happy, it can continue to power itself for centuries without outside interference, possibly forever as the city expands and the population grows" Princess Amore spoke, as the ponies began to smile once more.

"But how are we going to lift the spirits of the entire city? Most of the population is already feeling depressed, so I doubt mere words would be able to change their minds and hearts" Sombra said, as Airy giggled once more "That's why we need something big! Something that makes everyone happy; A Faire!" she declared, as Princess Amore turned towards her "A Faire?" she asked, not understanding the point.

"Yes, a Faire; Everyone loves a party, so what better way to lift the spirits of the people than giving them a reason to be happy. Once you've installed the new enchantment into the Crystal Heart, the Crystal Empire could hold a Faire to celebrate the new beginning for the empire, thus powering the heart and restoring all that was lost" Airy repeated as she flew to Princess Amore "But the question is... can you add the spell as an enchantment to the Crystal Heart?" Airy asked as Amore levitated the parchment, reading it once more as she wondered.

"Yes, I do believe it's possible... however, it will take few days to design the enchantment before we can begin planning the Faire. Thank you Airy, your ideas have been helpful" Princess Amore spoke as she turned towards said fairy, smiling as Airy hummed happily.

"No, rather thank you Princess Amore, for giving me a chance to help your people. If you don't mind me asking, how does one add enchantments to preexisting relics?" Airy asked, as Amore pondered the question for a while.

"Well, depending on the relic, one can directly alter the preexisting enchantments, add new ones by simply casting a spell or in the case of relics such as the Crystal Heart, and directly alter the relic to add the enchantment. I'll need to add the enchantment to a piece of crystal, then use magic to fuse it into the Crystal Heart; it will take couple of days for the fusion process to stabilize, before the enchantment begins to take effect" Princess Amore explained, as Airy nodded in understanding.

It was at this point, that Thunder Shield interrupted "Good luck with the enchantment, your highness. It's time I return to my duties" he said, before walking away as Glimmer looked at her sister "I guess it's time for me to start the work too. See you at court, sister" she said, following her husband back up the castle stairs.

Princess Amore and Airy turned their gaze towards Radiant and Sombra, who smiled at the princess "Well, I guess I’ll be assisting ponies today at the hospital; I would hate to see those poor dears suffer more than they have to" Radiant said, before turning towards Sombra "You should join me some time: it would be fun, helping ponies together" She said, as Sombra shook his head.

"Thank you for the offer, but I need to get back to my studies. Have fun, Radiant" Sombra said as he smiled at her, before watching as Radiant walked away from the castle, towards the direction the hospital was in. Turning towards the princess, he glanced at Airy before bowing his head "Have a good day, your highness" he said as he took his leave, entering the castle as well.

Princess Amore finally turned towards the final member of the group, who was still hovering next to her "So miss Airy, what plans do you have?" she asked, as the little fairy fidgeted her hands "Well, I actually wanted to talk to you about that; once the Crystal Heart has been properly restored, I would like to help the ponies more. As my world was more... advanced than yours, I would like to recreate things from my world in order to help the ponies of the Crystal Empire" Airy answered, as Princess Amore nodded her head in understanding.

"What an admirable goal. I'm sure my ministers and head of staff could help you establish a workshop for such tasks" Princess Amore said as she motioned with her head for Airy to follow.

Taking the hint, Airy followed as Princess Amore headed up the stairs, opening the castle doors as she walked through the hallways, following a familiar both towards the throne room "Your highness, there is also another matter I wish to talk about" Airy said, as the two slowed to slow, casual pace, as Amore turned her head to look at the small fairy flying besides her.

"Before I talk about it, I wanted to know if there are any... unbreakable magical oaths that one can take" Airy asked, as Princess Amore paused her steps, looking at Airy with confusion "Yes, there is one... but why would you require one?" Princess Amore asked in turn, as Airy shook her head "I'll explain in a moment, but can you describe how such oath works?" Airy asked as Princess Amore nodded.

"The oath is a sacred one, usually performed by two unicorns, though as long as one unicorn is present to cast the spell, anypony can perform the oath, unable to break it unless both agree to it. As such an oath is powerful, it is a type that nopony could bear more than one actively at any time, even a unicorn as powerful as I could not hold more than one active oath" Princess Amore explained as Airy nodded her head in understanding.

"If two ponies agree to hold a secret their entire lives, would the oath hold even if one lived only a year longer and another a century?" Airy asked, as Princess Amore pondered it for a moment "Well, yes; the oath between two ponies should last, as long as there are no conditions that the oath would break upon one's death or after certain time" she explained, pausing for a moment before continuing "Now, why is the oath important to you?" she asked in return.

Airy fidgeted her hands, nervously glancing down before checking to make sure no one else was within hearing distance "I... If it's okay with you, I would like to learn the enchantments within the Crystal Hear" Airy answered, as Princess Amore's eyes widened "What?" she asked, completely shocked; she had not expected that from the little fairy.

Airy was quick to speak once more "W-well, it's just... Ever since I came to this world, I've felt regret at not being able to help more with the Crystal Heart. I never learned how the Crystals work, so all I could do was give vague ideas; it might have worked now, but in the future it might not" She explained 'nervously', pausing to glance around before continuing.

"A-And I learned that since you're the only one who knows the Crystal Heart's secrets, I grew concerned; I know that you intend to make Radiant Hope your successor, once she's finished her education under the Princesses of Equestria, but.... what if something happens to you before you can pass on the secrets of the Crystal Heart to her?" Airy asked as Princess Amore opened her mouth to reply, before closing it as she realized the depth of little fairy's concern.

"We, the Cryst-Fairies, live for thousands of years, some even tens of thousands. That's why I asked about the oath; the current crisis with the Crystal Heart came unexpectedly, so there's no way of knowing if or when the next crisis comes. I wanted to ask you to share the enchantments, so I can make an oath to keep them a secret my entire life, not sharing or tampering with the Crystal Heart in any way... unless a day should come, that one of your successors down the line fails to pass on its secrets or misuses the Crystal Heart, willingly or unwillingly, in a way that endangers not only the relic, but the very lives of the Crystal ponies as well" Airy continued speaking as Princess Amore stood still, thinking about everything Airy had just said.

"I know that it's much to ask, but... Well, in the last three weeks that I've known them, I've realized that Radiant is still young and naive, while Sombra is... well, he has issues he needs to deal with. If a villain were to capture them, they could use one to make the other reveal the secrets, which is why I asked about the oath; that way, I alone would bear the burden as secret keeper, while ensuring that never again would it's secrets be forgotten" she said as Princess Amore stood still, looking at the little fairy with blank expression.

Airy lowered her head, as she fidgeted her hands once more "I don't expect an answer now, maybe I’ll never receive one since it's a huge responsibility and show of trust, but... I wanted to ask you anyway, to let you know that I wish to help you in any way I can" Airy finished speaking, looking down at her hands.

A moment of silence stood between the 'nervous' fairy and the princess, either speaking or moving as the latter considered Airy's offer.

Airy wasn't sure how long it was, until Princess Amore raised her hoof, holding it steady as Airy took the hint, slowly landing on it as she raised her 'nervous' gaze to look into Princess Amore's eyes "Are you certain, that you wish to bear such a burden?" Princess Amore asked, as Airy nodded with determined look "Yes, your highness. Anything to help" she answered.

Princess Amore looked at her for a moment longer, before nodding her head as she lowered her hoof, with the little fairy taking flight once more "Thank you, I’ll consider your offer. I'll make a decision by tomorrow morning"

"Tomorrow morning?" Airy asked, as Princess Amore nodded "Today, I’ll instruct my ministers that I’ll be taking a few days leave, so I can pay my full focus on creating the enchantment for the Crystal Heart. As such, I’ll let you know tomorrow morning if I choose to share the secrets of the Crystal Heart; that way, we can achieve both task at the same time" she explained as Airy nodded.

"Are you sure it's enough time to consider?" Airy asked, as Princess Amore nodded her head once more, before continuing to walk towards the throne room "Yes, I am sure. Now come, it's time for you to meet the rest of my court" she said as Airy followed....

Princess Amore glanced at Airy as she hovered on the side, talking with minister of finances and Swift Clean about the workshop and advertising agreements with the local spa, as well as potential manufacturers for her products, once she delivered the designs of course.

The court had welcomed Airy quite openly, interested of their otherworldly visitor. Already, Airy had offered to create a solution to replace the low wood supply meant to keep ponies warm or to cook food, though it would take until after the Crystal Heart was restored before she could start working on her... 'Oven' and 'heater', as she put it?

Princess Amore turned her attention back to the paperwork in front of her, reading through the drill reports as she wondered about Airy's offer.

It made sense, in a way; Airy's very nature and personality screamed sincerity, as she voiced her concerns. Princess Amore had not even though about the things Airy had brought up before, but in retrospect all of them made sense. Her analysis of the situation, potential hazards and even why Princess Amore had not yet shared the full secrets of the Crystal Heart with Radiant and Sombra were spot on, everything seemed so logical and thoroughly thought out.

But the question still stood; Did she trust the little fairy enough to share the secrets of the Crystal Heart? Could she place such a monumental burden on the tiny little fairy, who only wished to help? To place such a sacred, unbreakable oath on the shoulders of a little fairy so new to these lands?

It would be a long day ahead, as she pondered the question in her head....

The hallways of the castle stood silent, with only occasional guard patrol interrupting the silence of the night, their armor clanking as the sound echoed through the empty halls.

Two old guards in front of the vault stood still, keeping a track of the lieutenant as two other guards followed him, before stopping in front of the old guards as the lieutenant spoke "Epsilon" he spoke, as the guard right of the vault answered "New sun", saluting as the replacement guard saluted in return "Fallen sky" the new vault guard answered, before the two guards dropped the salute, with vault guard passing his weapon to new guard, before they switched placed.

The process repeated with the second guard, exchanging code words and then passing the weapon to replacement guard, before the old guards followed the lieutenant out of the vault corridor, leaving the fresh guards standing ready.

There were three vaults spread across the castle, with each having their own protocols and guards; one for the bits, the second for magical relics and third for restricted books. Unlike the first two, the book vault only had an enchanted iron bar door, a relic left behind by old unicorn ministers. As it was quite a habit for former ministers to visit the vault to read books, Princess Amore had decided to keep the old iron bar door, so that they could easily talk to whoever was visiting the vault without needing to open it every time.

Of course, the door wasn't without security: the thick enchanted iron bars blocked anyone from entering the vault, naturally or magically, while the locks required magical keys, which were only carried by Princess Amore, Radiant Hope and Sombra. As such, only those three would be able to access the book vault without getting overwhelmed by guards within minutes (which would not be long enough to even strip the locks off the door enchanted by Princess Amore herself).

Which meant that the book vault was practically impenetrable to any normal intruder... the key word being ‘normal intruder’

Airy hovered above the vault, hidden in the tall ceiling as she looked at the two guards standing below, before slowly beginning her descend, carefully avoiding detection.

"Charm" she whispered, as two thin pink sparks of magic slammed into the two guards’ heads, who stiffened for a moment before relaxing as they turned to look above them, where Airy now hovered: both of them wearing smiles as their eyes glowed pink.

"Return to your positions, act normally and ignore me during your entire shift" she commanded, as the two guards nodded their heads before straightening their pose and returning to task of guarding the vault, neither giving a hint of being under magical influence anymore.

Smiling at the results, Airy turned towards the door, as she examined the enchantments placed upon the door and the vault itself. It was like a spider's web of enchantments, weaving across the walls, the floor and the ceiling, preventing anyone from getting in while also protecting the existing enchantments with more enchantments, including alarms that were connected to several individuals.

It took Airy nearly half an hour to examine the vault, before she was almost certain she could get in and out without triggering anything. The simple examination was not enough to trigger alarms, while outright attack on vault or the enchantments would. There were many enchantments that reinforced the every part of the walls, floor and ceiling so tightly, Airy doubted even she could brute force her way in.

However, there was an oversight: the vault did not have anything preventing from physically slipping in or picking up the books inside the vault, only protecting from magical or physical intrusions into the vault by those of large size. Airy smiled as she flew closer, before carefully landing on a horizontal iron bar of the door, watching the enchantments as they did... nothing. No reaction whatsoever.

Airy giggled to herself, as she took flight once more, slipping into the vault as she gazed at all the books lining the bookshelves, heart beating with excitement as she spotted her first book on soul magic.

Taking one last look at the two guards, Airy turned her back towards them as she gathered her magic, a ball of dark purple energy forming around her before releasing as thick purple fog, which spread until it formed a sphere almost twice as tall as Princess Amore. Soon, the fog dissipated, revealing the monstrous form within.

Airy stretched her purple-orange larvae form, finally relieved to experience being proper size as she moved her five pairs of hands one by one, still little unfamiliar at controlling them at the same time. Beneath her, the three pairs of legs moved as she turned towards the door, checking on the guards while running a hand over her head, touching the pair of antenna's as her two pairs of orange butterfly wings fluttered behind her.

Currently, her size would have towered even Princess Amore, standing nearly twice the size at her full height.

"Tell me, how long until the next guard shift happens?" Airy asked, her voice carrying a deep echo as one of the guards turned his head to look at her "Six hours from now, mistress" he replied with a smile on his face, looking at her like she was the love of his life.

Airy waved her hand, dismissing the guard as she returned to the bookshelves, picking the first book on her list "Basics of soul magic by Dapper Thornhorn" from the shelf, turning it in her hands before flipping the cover open as she began to read the first page.....

Author's Note

Just wanted to inform you that this story is barely starting: to others, establishing that Airy might come to know the secrets of Crystal Heart, is charming Sombra into learning dark magic and that Snow Antler is returning for vengeance would be a mid-point in a story.

Well, that's not the case. I'd say by end of this first arc, there's gonna be... four or five more arcs. As for this first arc? i'd say it's about... 1/3rd, maybe 1/4th done, so don't worry.

Make note, readers: procrastination is the enemy of us all.

PS: Edited the prologue, so there's a short clip at the start. Enjoy