The Promise

by ThePrinceOfTheNorth

Rating: everyone
Tags: Original Character, Tragedy, Princess Celestia, Slice of Life, Twilight Sparkle, My Little Pony: Friendship is Magic, Alternate Universe, Sad, Other, Romance, Princess Luna
Length: 2352

If the one true friend asked you to do one thing with their dying breath, would you do it? If you could someday bring them back, even at the expense of your own life, would you? I can tell you of one who would....

This a story once told before, about a Princess who died long ago, and was replaced by her closest friend. How did this friend become so? How was her true identity revealed to her student? And why, oh why, did she risk her own life?

This is the story of Queen Crystalia and Princess Celestia, sisters by all but blood.

This is how they became friends, how they were torn apart, and how one of them nearly gave their own life so that the other might live.

This is the promise that Crystalia made, and the promise she swore to keep.

Inspired by Princess Celestia: The Changeling Queen by vren55
Based, in part, off the original The Promise by yours truly.

Published 2015-07-19 22:10:02 UTC
Last updated 2015-07-23 06:54:08 UTC

Prologue: The Beginning

Today, the Princesses Celestia and Luna are two of several of the most recognizable figures in the whole of Equestria. And yet, to look at them long ago, you would not recognize them. Before the sisters sealed Discord in stone, before they turned King Sombra to shadow, before the Crystal Empire fell to him, and long before Lord Tirek laid ruin to Equestria, they were but two alicorn fillies, both sharing the same kind and loving mother, the alicorn Faust, and mysterious and illusive father, whom neither can seem to recall. It was in these days, when the two were carefree, that something unexpected happened. Something from.... the north.

Celestia was playing in the meadows just outside the Everfree Forest, in fact, where the town of Ponyville would one day stand, when she spied something white on a distant hill, laying in the tall grass. As she was a curious little filly, Celestia decided to go and investigate, taking little heed to the warning of both her guards and her sister, the former of which she promptly dismissed, though little Luna was too afraid to follow.

After a short canter, Celestia grew close to the white thing, only now realizing it to be some creature she'd never seen before, but, at least to her, it looked an aweful lot like something she'd read about one time when Faust had taken her to field trip to Manehattan, though she admittedly liked the small town. A Changeling.

The creature, assumedly a Changeling, was mumbling something. From what Celestia could make out, it was talking about a teleportation spell and how it had almost no idea where it was. As Celestia drew closer, though, the incessant mumbling ceased, and the Changeling raised and turned it's head to look at her.

If this 'thing' was a Changeling, then those books she'd read were boloney. It had vibrant magenta eyes, a pink mane and tail, and a straight horn. It's 'chitin' was white, and it didn't have the 'carapace' thingy that the books said all Changelings have, though it did have the weird bug wings.

After the two had stared wide-eyed at each other for what seemed like an eternity, but was really only five minutes, Celestia decided to break the silence, before it got awkward. "Hi?"

The Changeling blinked. "Ummm.... hi?"

"My name's Celestia, what's yours?"

"My name," the Changeling asked, to which Celestia nodded with vigor, "My name.... it's Crystalia."

"Crystalia," Celestia said, turning her head to the side and raising a brow, "That's a funny name, isn't it?"

Crystalia deadpanned. "What, and Celestia isn't?"

Taken aback, Celestia was at a loss for words. "Touché."

"Umm," Crystalia said, "I know I'm not supposed to talk to strangers, but you seem like a nice pony."

"I'd like to think that I am," Celestia replied, "I'm going to be a Princess someday, after all."

"And so is every oth-," Crystalia began before holding her tongue. Wait, she's a winged unicorn. I remember one of mo....my guards....saying something about there being winged unicorns in a placed called Equestria. What did he call them again....alicorns? That must mean....

Crystalia's eyes widened as the realization dawned upon her, and she quickly leapt to her feet and bowed. "Forgive me, I'm just a stupid hatchling. I didn't know that you wer-"

Crystalia was stopped dead as Celestia burst out into a laughing fit, rolling around on the grass, and holding her sides as if she was full to burst.

"Celestia," Crystalia asked after Celestia seemed to have calmed down somewhat, "What was.... that about?"

"Oh, nothing," Celestia said as a smile graced her features, "Just that it's my mommy who's the Princess."

"Oh," Crystalia said, her cheeks flushing red, a response which made Celestia giggle.

"I like you," said Celestia, "Do you think we might see each other again someday?"

Crystalia was again taken aback. Was this pony really asking to be friends with her? All her Royal Guards had told her that ponies were all evil, and could never be trusted. And yet, this little filly was none of those things. In fact, she seemed to have more in common with Celestia than she did with her own kind. And so, after a long and hard thought, Crystalia finally decided upon her answer.

"I'd like that," she replied, a smile crossing her fanged lips, "Where, though?"

"Ummmm," Celestia mumbled, "Where do you live?"

"It's," Crystalia began with some uncertainty, "I'm pretty sure it's to the north of here."

"The we can meet at the northern end of the Everfree Forest," Celestia said brightly, "Does that sound okay?"

Crystalia nodded, "Sounds fine to me....ummm, do you think you could send me home? I'm not too good with the teleportation spell, yet."

"Sure," Celestia said, "Mommy said to teleport somepony else, all you had to do was think of where you wanted them to go. So, if I think that I want to send you where you want to go, you'll go there!"

"Ummm....okay," Crystalia answered at length, "There's no place like home, right?"

Celestia closed her eyes and focused her magic, and Crystalia closed her eyes too, thinking of home. In a flash, Crystalia disappeared, and reappeared many kilometers away, right where she had been before. Even now, she looked forward to seeing her new friend again.

And she her, she would. And, in time, the unlikely duo would become more than friends, but sisters in all respects but by blood. And as the decades passed slowly by, Celestia and Crystalia grew older, yet the continued to meet, and with each meeting, Crystalia grew to look more and more like her adopted sister. And it was, before that most fateful day one thousand years ago, that only three features could tell the two apart.

One had fangs and chitin, on which there was also a sun cutiemark in the same place as there was on the fur on her flank.

Author's Note

It seems like it's been a very long time since I've started a new story, and even longer since I knew where I was going with it.

Chapter 1: Weddings and Worries Galore

"And so, by the power vested in me by the alicorn Faust, I hereby pronounce you stallion and mare. You may kiss the bride."

After the first wedding had been ruined by Queen Chrysalis' failed invasion, stopped only by the power of the bond shared between Cadence and Shining Armor, this second attempt at the wedding had nearly double the security. Heck, even the enigmatic Princess Starlight Waltz from the north had committed a small guard force, which had surprised even Luna.

As Shining obviously wasn't about to let this moment be sullied yet a second time, he pulled Cadence into a long and heartfelt kiss, one that lasted a good two minutes before either of them was willing to let go of the other. As such, it was Cadence who broke off their kiss.

"We're finally ma-", Cadence began, only to be cut off by a loud bang, originating from Pinkie's Party Canon. Celestia chuckled. I suppose Pinkie will be Pinkie, no matter what.

From Celestia's position above the altar, she could clearly see Twilight facehoof at Pinkie's usual antics, as Twilight so often did when Pinkie did something.... Pinkie-like.... in public.

"OH YAY," Pinkie Pie almost yelled as she bounded about Shining and Cadence, "Now I got to throw a 'You're Finally Married For Realzies Party!"

"Pinkie," Celestia began in as kind a tone as ever, "There will be time for your party later. For now, you have a proper party to attend to."

"But of course, your Princessliness," Pinkie said with a big smile on her face as she bowed low in a comical manner, sending gasps throughout the proper ponies gathered in the hall. Celestia watched as Twilight again facehooved, but she, Cadence and Shining only chuckled a bit.

"I'm sure that your party will be much fun," Celestia said, a kind smile on her face, "But that will be later. For now, would everypony care to join the bride and groom in the Royal Gardens for cake?"

The festivities that evening held in celebration of Princess Cadence and Shining Armor's wedding were both immense in scope as they were grand in nature. Whole tables of many different foods from all corners of Equestria, ranging from Manehattan-Style Cheesecake to Apple Family Cider, even some of Canterlot's finest bakers had supplied a whole assortment of goodies and pastries, all of which Celestia was digging into in as discrete a manner as possible. Oh my, when was the last time I had such fine cooking? Probably this morning, but sti-

Celestia was interrupted from her thoughts as she realized somepony was trying to talk to her. In an instant, she had spun around only to be greeted by Cadence and Twilight, both of whose faces were very blank, almost to the point that it gave the Sun Princess the chills.

"Twilight. Cadence," Celestia said, nodding to both of them in turn, "I must have been caught up in thought. Forgive me, but what is it you two were saying?"

This can't be good, Celestia thought inwardly.

It was Twilight who spoke first.

"After Cadence and Shining created that wave of love that got rid of all the Changelings," Twilight began, "I noticed that you seemed affected by it as well."

Celestia managed to suppress the look of shock and terror that wanted so desperately to grace her features and spoke. "Really, now, Twilight, that's impossible. That blast of love only affected Changelings."

Way to dig your own grave, Celestia thought to herself, realizing that what she'd just said could give her away. Fortunately, Twilight and Cadence didn't seem to notice.

"There was something else," Cadence added, continuing Twilight's train of thought, "After some talking between ourselves, Twilight and I noticed that, at least, for a small while after that wave of love enveloped you, that you had fangs. We talked to several other ponies, as well as Twilight's friends, and the ones who did manage to glance you also recall seeing fangs."

Celestia furrowed her brow. "Are you two sure of this? Are you really going to accuse your auntie of being a Changeling spy?"

"WHAT," Cadence almost yelled, taken completely aback, "I would never accuse you of that! Never!"

"What we're trying to say," Twilight stated, "Is that we're worried about you."

Celestia gave both Cadence and Twilight a warm smile. "I can assure the both of you that everything is fine. Now, I think it best that I retire to my chambers now. The sun will be setting soon. I'll see you two later."

With that, and before any further argument could be put forth, Celestia turned and made her way back to the Castle.

"What do you think, Twi," Cadence asked once Celestia was out of earshot.

"I think she's hiding something," Twilight replied. "Maybe being cocooned affected her more than any of us realize, even her."

Philomena watched Crystalia pace back and forth in her chambers, looking like she had just seen Celestia's ghost.

"They suspect the truth," Crystalia explained to Philomena, who actually was listening intently to her master's troubles, "I know they mean well, Philomena, but what if they put it all together? I was acting terribly unlike her during the wedding reception in the gardens when they questioned me. They saw what the wave of love did to me: what it revealed about me. This.... this is bad.... very bad...."

Philomena cocked her head.

"Maybe I could ask Crystal," Crystalia began, but quickly halted that train of thought, "No, she's too busy managing the Hive. No, I need to come up with a plan. Oh, what would my sister do? If she and I were younger, we'd probably blame either you or the butler."

Philomena was about to start screeching in Crystalia's ear, but a knock at the door halted her, and stopped Crystalia's endless pacing, rousing her from what was most likely growing paranoia and insanity.

Shaking her head, Crystalia approached the door. "Who is it?"

"Your sister," came Luna's voice from the other side, "Let us in at once, dear sister. Twilight Sparkle has spoken with me, and we're concerned about you."

"You haven't been acting like yourself lately," Twilight said from beyond the door.

Crystalia looked to Philomena, who seemed to somehow know what she was thinking, and she shook her head against it, to which Crystalia sighed. Looks like today is the day, then.

Taking a deep breath, Crystalia cantered over to the door as slowly as she dared. She placed her hoof on one of the handles, and looked at Philomena one last time. Philomena nodded in turn.

"Well, here goes everything," Crystalia whispered as she opened the door.

The ponies gathered on the other side of the door to the Sun Princess's Royal Chambers; Luna, Twilight, Cadence, Blueblood, and Shining Armor, all of them where shocked by what they beheld.

Standing in the door was a pony as tall as Princess Celestia. It had her mane, her tail, her horn and her fur. Her eyes looked just like those Luna had always seen and remembered, as did the rest of her, right down to the cutie mark. But there was one thing, one small detail that took all but Blueblood completely off guard.

The small, regal fangs.

Celestia looked at the assembled ponies, a sad smile on her face. "I'm afraid Princess Celestia isn't here right now. In fact, she hasn't been here for a very long time. But I have. My name is Crystalia, and I am Celestia's best friend."

The jaw of ever pony gathered dropped.

Author's Note

Yes, any excuse to eat cake, right?

Anyway, I am, as ever, coming up with all this as I go, leaving nothing but the main idea to guide me along.

Now, how does one think that each of the gathered ponies will react, hmm? I'll let you guess.