Once upon a time, in the land of Equestria...
There was a magical tree in a magical swamp, at the furthest reaches of inhabited land. It grew against all odds, from a seed that even a squirrel would not eat, spreading its roots through the hostile wetlands that had claimed the life of so many ponies. The tree was a survivor, fighting every day to exist and grow stronger, feeding on the remains of the fallen ponies and the insects that lived within the swamp, with no help from any other plant or creature.
Then the day came when the tree cracked open, and we emerged. Like the tree from which we spawned, we were survivors, a marriage of the shapes of the ponies and the insects, with hard shells and sharp teeth, able to fly and cast magic both. The only thing we needed to continue our existence was love, and so we roamed in search of it, leaving the land of our birth and finding the lands of the ponies.
Ponies, which we'd been molded into the shape of. Ponies, who we could take the form of at will.
Ponies, who were filled to the brim with the most delicious of love. Hoarding it all for themselves, when we were the ones who needed it to soothe our aching hunger.
It was when we stormed the cloud city of Timbucktu, besting King Orion in combat, that I earned my crown and took the title of Queen Chrysalis. I had proven that I could lead us to a victory, and the love of the ponies for their home took the edges off our razor-sharp hunger for a time.
We roamed the land, searching for meal after meal and expanding our swarm. Walls crumbled and armies fell to our might, our power and cunning equal to none.
Until Trot.
After we had rightly bested that buffoonish Emperor Incitatus, the Avatar of the Sun descended. We were cursed, scarred, and sealed within a volcano, brought low by the likes of an alicorn.
The prison couldn't hold us long, but there was no need to let our enemy know that we'd broken free. We laid low and waited, feeding where we could without raising suspicion, until the perfect opportunity presented itself: A royal wedding, right under the sun's snout. By the time anypony had realized that I'd replaced the bride, I'd devoured enough to best the alicorn...
Until we were thrown out of the kingdom thanks to the efforts of the happy couple themselves.
So we did the same thing. Laid low, prepared ourselves, and at the right moment, took our revenge. My drones replaced everypony of note, taking over key positions within the kingdom, placing it under our control in one fell swoop. With them in place, more replacements were poised to follow, and soon our entire swarm would be in position to eat their fill. We had been thinking too small in just taking over places like Timbucktu, Trot, or Canterlot. Now, we would have everything.
Only for me to be betrayed. One of our own had forsaken us, had forgotten his roots, to instead cater to the whims of ponies. To be friends with our food. And despite all I had done for the hive, all I had ever done, no matter how close we were to total victory over Equestria, my hive that I had nurtured and grown from the moment that the first of us stepped out of the tree, they sided with the traitor.
But I was able to look into the eyes of the pony who poisoned him against us, and learn her name.
Our story isn't over, Starlight Glimmer. It will never be over.
The changelings will always rise again.
It'd been a week since she'd stood before the Tree of Harmony, among what was left of her treacherous minions, and once again sworn revenge.
Right now, Chrysalis was still in the forest, but nowhere near that accursed tree. Lingering near such a place made her ears ring and her horn itch--being born of dark magic made being near something so purely harmonious anathema to her, or else she would have stolen the trinkets during her initial invasion instead of just placing her army in between the Elements and their bearers--not to mention that there was a chance that Twilight Sparkle and her friends would come to retrieve the Elements of Harmony for something and she'd be caught right next to the source of their power.
As much as standing in between the six mares and their precious Elements would be satisfying, it would only be satisfying right up until the little alicorn started charging her horn.
Alicorn. Twilight Sparkle, an alicorn. When Chrysalis had first found out that she'd ascended, it'd sent her into a frothing rage, at the sheer audacity of Celestia going and creating a little purple clone of herself, and doing so using the unicorn who had foiled her invasion due to her inability to just let her suspicions go and enjoy the wedding, as well as her inability to stay put in the caverns like a good little prisoner.
Chrysalis hated Twilight Sparkle, almost as much as she hated Celestia for devastating her army and marring her beauty back at the battle of Trot. She'd never thought anypony would transcend her loathing for Celestia, at least until she'd met Starlight Glimmer who had unraveled her hive in an instant.
She'd nearly lost everything at Trot, but she'd rebuilt. She'd nearly lost everything at Canterlot, but she'd rebuilt. She'd truly lost everything in the heart of her own hive, and the ashes of her attempt to rebuild were still littering the base of that crystalline tree. And now she was laying on the floor of a forest, desperately trying to sleep.
Everything hurt. The hunger of the changelings--true changelings, not what the traitor had turned them all into--was constant, even for her, but she'd used to be able to hoard enough love to take the edges off, make it more of an ache that she could ignore if she focused hard enough on her next task. She had grown accustomed to that low-level ache. Complacent, some may have said, if they did so where she couldn't hear them.
Right now the organ that her body used to store love felt more like it was filled with razor wire, a sensation that had embedded itself in every muscle as well, and behind her eyes. The holes in her legs were larger than they had been; that was part of that blasted sun-mare's curse, that the scars that would never truly fade, not for a true changeling, grew deeper when their all-consuming hunger was at its peak. And her magic...
She'd put a lot of herself into that spell, to create those doppelganger ponies. Too much. Trying the spell again--not that she would, after those ungrateful false ponies had betrayed her just like her changelings had--would be life-threatening.
There was dirt in her mane. In her wings. In the widening holes. She didn't have the energy to groom herself anymore, was too malnourished to create the special secretions that would clean her body and mend her carapace. Leaves would stick to her when the wind blew, the chill breeze cutting through her. Animals would creep up sometimes, wondering if she was something dead that they could eat, and she would have to hiss to scare them away.
Chrysalis wasn't dead, but she was dying. Slowly but surely. She could feel it.
Starlight Glimmer. Twilight Sparkle. Celestia. Killers, all. Her blood was on their hooves, even if the bleed was slow.
No. She would get out of this. She would rebuild, as she always did. She just needed a bit of love.
But it was getting harder to even find the energy to shapechange, and animals could barely give her anything. They could love, because nearly anything with a brain could care about something, but it wasn't nearly as potent as the love that sapient creatures felt. It wouldn't save her, just slow her deteroration.
She needed love, and a way for ponies to give it to her. While looking like herself. But why would any creature--
Wait.
Chrysalis's eyes opened, and it came with instant regret, the pain behind them spiking. She ignored it. She needed to get up, needed to move, because she had an idea. A plan.
There were ponies who would give her love. Who would help her heal. There would be no more sleeping in the dirt, and she would rebuild right in the heart of her enemies' home.
She just needed to remember what the right words had been.
"Twilight, we have a situation!"
Twilight Sparkle, for not the first time, considered keeping a running tally of how many times Starlight had burst in on her while she was working through a mountain of administrative paperwork. Becoming a member of the royal family hadn't put much on her plate, but running a school? That had swamped her, to the point where she'd had to push back reshelving her personal collection of books twice, and the stress of doing so had her wings twitching as she slowly set the quill in her magic down.
She took a deep breath. "Did one of the students set off a destructive prank, get in a fight, disappear, or otherwise threaten a diplomatic incident?"
"No!"
"Did the map call on you to a solve a friendship problem again?"
"No!"
"Did you let your emotions literally get away from you again and start infecting other ponies?"
"That was one time!" She lit her horn, and one of Twilight's front legs was encased in magic, which started to tug her off of her sitting cushion and toward the study door. "You need to get outside right this minute! Ponies are panicking."
Twilight closed her eyes, giving a long-suffering sigh. "Okay, fine..." Given that the ponies of Ponyville could react to rampaging bunnies with horror and a rampaging bugbear with indifference, she didn't see their response to a situation as a good yardstick, but if Starlight was upset, there may be something to it. "Hold on."
With a flash of light, they teleported, and her hooves met the path outside of her castle, with Starlight right beside her. It took a moment for her vision to clear, and when it did, she recoiled.
Former-queen Chrysalis was laying on the path in front the castle, one front leg crossed over the other and head held high as if the dirt were a fine silk cushion. Her fangs were bared, but in a smile, and she looked downright serene as she laid there, barely twitching a muscle.
The ponies around her were not serene. Twilight's ears flattened as the latest one to wander by let out a piercing shriek, the earth pony stallion managing to high-jump into a nearby tree with sheer fear-borne desperation, and he wasn't the only one. Any pony who wandered near tended to run, fly, or otherwise make an immediate, hasty escape. While the attitude toward changelings in general had become much more positive in town, this wasn't just any changeling, and everypony who spotted her instantly recognized the enemy of Equestria who had, until now, been at large.
Whatever Chrysalis felt about these reactions was hard to tell, because other than a brief sneer of disgust in Starlight's direction, she only had eyes for Twilight. "Ah, Twilight Sparkle. Just the princess I was hoping to see."
Twilight's legs went into a bracing stance, and her horn lit with magic, ready for the moment her enemy would leap toward her. "Why are you here, Chrysalis?"
There was no lighting of horn in return, none of the crawling sensation of Chrysalis's repulsive magic in action. She, instead, slowly--strangely shakily as well--got to her hooves. And then bowed. "I, Chrysalis, hereby pledge mine self, body, heart, and soul, to Princess Twilight Sparkle, to be used in any way that she see fit, as her harem mare."
"WHAT!?"
She didn't flinch at all at that outburst, merely smirking. "I believe your line is, 'We accept, oh humble mare, and place thee 'neath the soft shelter of royal wings.'"
Twilight's horn went dark as she sputtered, unable to hold a spell in the face of her shock. "What in Equestria are you talking about?"
Chrysalis slowly rose out of her bow, and the amused smirk never wavered. "Are you telling me you don't know?" She shook her head slightly. "Shame on you, Princess, not knowing the laws of your own land." She lifted one of her hooves and started to gesture with it a bit as she lectured. "Any creature may approach any princess of Equestria and offer themselves to be in their royal harem, no matter their circumstances, their past, or whether they're even a citizen of the land. It's a law that's existed for centuries."
The hoof lowered again as Chrysalis continued. "And given the state I've been in since THAT ONE--" The serenity and amusement was suddenly shattered, and Starlight jumped at the full force of the royal changeling's fanged snarl. "--Turned my own people against me..." The fury melted away again. Too quickly, as if she didn't have the energy to maintain it. Her posture drooped, and Twilight was taken aback by how sorrowful she looked. "If the choice is between starving in the cold, or being yours, then I've chosen to swallow my pride."
Starlight snorted, even as her tail gave a nervous lash. "Careful not to choke on pride that big."
If Chrysalis heard the mutter, she didn't react to it, her eyes focused entirely on Twilight. "I trust that your royal compassion will have you making the right choice."
Twilight stared at Chrysalis. It felt like Discord had suddenly backslid and gone on a rampage. Up was down, cats were dogs, and one of the most vicious of Equestria's enemies was offering... something she could scarcely comprehend anypony or anyone offering. It felt like it had to be a trick, and yet...
Chrysalis's legs were shaking, like it took an excess of effort just to keep standing. Her mane was disheveled, her carapace had lost its sheen, and some deep instinct of Twilight's told her that she smelled ill. Not having caught any particular sickness, just unhealthy.
Changelings could shapeshift. Could trick. But if she were wrong and Chrysalis was really in such a dire state...
She took a deep breath. "Starlight, find Spike and get him ready to send letters to Canterlot and the Changeling Kingdom." She saw Chrysalis twitch a little at those words, but she also saw her starting to lower herself back to the dirt. "Before we welcome in our new guest... I want to do some research."