The silence in the library wing of the new Castle of Friendship was unusual given the ruler in question, but with her new diplomatic duties taking an ever bigger part of her life, Twilight had to come to Canterlot post haste, and leave her studies at home. That silence was broken with two distinct foot sounds coming to the door. One was in rhythm, sophisticated and trained. The other timid, making sure to be as silent as possible.

“I am telling you darling, Twilight will not be mad,” Rarity said to assure her friend in her characteristic eloquent manner. She was dressed impeccably, as expected of the town’s fashion guru. A wonderful purple jacket over a black shirt with her jewel symbol graced her feminine physique, and a black skirt, with white boots finishing her outfit. It was not her best, but it was casual Sunday.

“But Rarity, we didn’t ask for permission, at least from Spike,” Fluttershy replied, her voice like a breeze on a summer day. Indeed, the pegasus was the epitome of sweet innocence. Some plain jeans with butterflies sewn onto her thigh side, a pair of retro sneakers for when you don’t want to make a sound, and a nice light pink shirt with flowers on the front, with a hole on the back for her gorgeous wings.

“And wake the poor darling up just for that? No need for that, we only need one book, and we are off.” Rarity assured her pegasus friend, already scanning the vast shelves of the new library.

Fluttershy complied and began to search as well. The two mares shared a moment of silence, with only the rustle of papers interrupting their studies. It took them a long time to find anything useful, only for Rarity to notice a book behind a shelf. It was wrapped in chains, but not too tightly. She hesitated, but the pull of its green cover made it impossible to resist. Making sure Fluttershy did not see where the book came from, she quickly took it, using her magic to unlock the chains.

“Ah yes, this could be it! “Release Dominance” by Starswirl The Bearded. ” Rarity proclaimed, making Fluttershy jump in her place. She lied about the author, as the real one’s name was smudged by age.

“I don’t know about this… m-maybe we should wait for Twilight to come back?” the timid mare said to herself, almost hoping she would not be heard.

“Pish posh! I know your recent attempts at gaining assertiveness have met with mixed results, but one more couldn’t hurt. Imagine helping not just the Breezies, but also other animals and ponies as well!” Rarity replied, making Fluttershy remember her adventure with the miniature creatures, and nod in agreement.

Rarity herself could not explain her sudden willingness to try this magic on her friend, but she quickly opened the book and read the incantation.

"Enter quickly, take haste,

Do not let this soul to waste

By being timid and reserved

Let it take what it deserves

A true dominant force it will be

Once you make it see

That owning ones will

Is the only real thrill”

The white mare floated in the air, her horn shining dark and purple. Rarity never felt such power, and her mind was getting thrills by just casting the magic that the book kept hidden inside. Even though Fluttershy tired to fly out of the way, the beam of darkness hit her full force, and she crashed onto the floor right between two massive bookshelves.

Rarity, her magical energy drained lost her consciousness as well, just soon as the beam left her glowing horn.

It did not take long for the magic to take hold of the element of kindness. She began to tremble, as a booming female voice echoed in her mind and soul. It was familiar to her. She heard it every day, or at least a softer version of it.

“Oh yes, this is quite the new home, my sweet Fluttershy. Such emotion, such unrivaled potential. I even love your alluring voice already.”

”Get out of my head, you fiend!” Fluttershy screamed, her own reply echoing in her mind, hurting her immensely.

“Fiend? No child, I am the thing you yearn for. Sure, you are kind, compassionate and just frankly, coma-inducingly cute. But there is more to you than that, isn’t it?”

”You know nothing about me, and I demand you exit my mind this instant!” Fluttershy commanded, the tone of her own voice giving her immense pleasure.

“Feels good, doesn’t it? Come on, command me more!” the voice teased her prisoner, making the mare hornier and hornier with each morsel of power the magic infused her with.

Fluttershy wanted to stop her voice from uttering more commands, but the desire her body was giving her overwhelmed any sense of reason and she complied by continuing to command her enemy.

“I, Mistress Fluttershy command you...” she stopped, rubbing the moist part of her jeans, and massaging her left boob ever so gently. She never referred to herself like that before. Fear began to creep in, only overshadowed by the lust her trembling body was giving her.

”Close enough, my little pony. You are getting very close to your destiny. I have seen your deepest secrets, your power over animals and ponies. Your Stare, it is only the tip of the iceberg, I assure you. Let me help you become what you have been seeking, but you could never achieve.” the voice explained, tempting one word at a time.

“No, stop, I beg...” Fluttershy replied, her will crumbling under the heat, and the truth in the voice’s words.

”No, no begging! You are not meant to beg, Mistress. Think about it, why are you so obsessed by your assertiveness? It is not because you don’t have friends. It is not because you have no job. It is because there is something inside you, something so glorious and powerful, and it wants to be free. The real you wants out, Mistress. She is ready.”

Protest as she might, the pegasus felt that truer words were never spoken, Was it the lust her body gave her? Was it that fact the voice did not lie? Or was this just the wicked magic piercing her and melting the kindness right out of her? She did not care anymore, she only wanted release – both a mental one and the wonderful physical one.

“Do it! Release me from this prison! Let me be free!” she exclaimed, her very soul being rewritten by the dark forces that were freed by her command.

The mare came, and as she did, a red explosion filled the library. Her clothes melted, turning black in the process. Her wings vanished, but she did not care. Those were wings of a lesser pony then her, and she did not require them anyway. Her bust increased in size, giving her more than an ample size. Her jeans became latex thigh high black boots, clinging to her long sexy legs. Her shirt became a corset that formed a leather butterfly, hinting at innocence long lost. Gloves formed up to her elbows, giving her the proper tools to welcome a lucky creature into utter submission. Panties, made from chains and another butterfly showcased the treasure in plain sight, giving those slaves some hope that one day they could be granted a taste of its nectar. And finally, a spiked collar, finishing the look of dominance personified.

The creature smiled, her eyes open for the first time. She could see clearly now, no moral or shy wall to stop her. She looked into her dark soul, only to find a new name, one that was worthy of her new status.

Mistress Butterfly. She smiled wickedly as the name fell into place, leaving the Fluttershy identity to disintegrate in the depths of darkness for all eternity.

Mistress Butterfly made her way to the now recovering Rarity, and stood above her. She enjoyed the view, the dazed but gorgeous mare coming to her senses.

”What happened... One minute I was searching for a book, and now I’m all covered in... Fluttershy!” Rarity yelled in shock, the outfit of The Mistress taking her by surprise, and giving the mare a sly smile in the process.

“Not really, my dear. My name is Mistress Butterfly, and I am here to take you,” Mistress Butterfly explained, her voice more firm and seductive. Its mere presence in Rarity’s ear made the unicorn aroused.

“What have I done to you!? Oh honey, I am so sorry! Quick, we need to get Twilight this instant.” Rarity explained, and quickly rose to her feet.

”Sit.” the Mistress said, the smile never leaving her kissable lips.

Rarity complied, and quickly sat. The act alone made her cream her panties. It just felt good to do as Mistress said.

“What are you doing Flutter...” Rarity said, fear entering her voice, just like her friend minutes ago.

“No, I told you, she does not exist anymore. Forget her... Now.” Mistress said, placing her gloved finger onto Rarity’s upper lip.

She then began to Stare, deep into Rarity soul. The unicorn remembered seeing this magic in action, but this was something even more powerful, It was as if the control of it was gone, and the eyes were attacking her willpower with full force. Her crotch was heating up and getting wetter with each passing moment. Forget, forget, forget echoed in her mind. Each time she forgot the name, a orgasm followed suit. She tried her best, but the hunger for carnal pleasure was greater even that her affection for a certain pegasus whose name escaped her mind. And then as the crescendo of utter bliss attacked her soul, she forgot the name, forever.

“Mistress Butterfly...” she muttered, her body going limp from the ecstasy of compliance.

But the Mistress was not done there. She needed a weapon of choice to tame such a proud mare, and a whip formed in her hands. Not by unicorn magic, but from the mere fact she wanted it.

“Now then, how about we finish your induction as my first slave?”

”Slave... No, please...”

“Poor thing, still having trouble accepting me as your reason to exist? Well, don’t worry, because you are going to LOVE ME!” Mistress Butterfly exclaimed, assaulting with her Stare once more, this time not to erase, but to rewrite her captives person, desires and dreams. It made the dark creature moist just thinking about it.

The word “love” echoed inside Rarity, each time giving the mare an orgasm, until it was a stream of utter bliss, leaving her virtually helpless in Mistress’s capable grasp.

The stare was like heaven to her, but a burning sensation prevented her from truly being engrossed in its magnificence.

“Why... Does it burn Mistress?” she asked, hardly managing to breathe, her words a jumbling mess of moans and screams.

“That would be your free will Slave. Such a pesky thing, isn’t it? Just let me get rid of it for you...” the Mistress explained, her voice like a angel’s choir to Rarity.

Coherent thoughts were beyond the unicorn at this point, but the will of Mistress Butterfly had to be done, and with her last thought as a free pony, she accepted the darkness into her heart, and the burning was gone, as well as her consciousness. For the second time today she was out, her body still twitching from the excessive amount of synapses firing, and dark magic penetrating her mentally.

It took the unicorn another hour to recover, only to find herself on top a king size bed that was covered in red, and her head in the lap of the reason of her existence, her sexy body exposed and on full display. She enjoyed the petting for a few minutes, her Mistress watching some footage of Twilight Sparkle at the event she had flown off to.

“Thank You, Mistress Butterfly. “ Rarity said, her mind clear of any doubt or regret.

“Of course my dear. You were my first choice even before my awakening. Well that weak pegasus’ anyway.” the powerful mare replied, her voice calmer now, but still fueled by a dark force.

Rarity tried to remember that mare’s name, but simply could not. It actually felt good that she didn’t. All that mattered was Mistress Butterfly now, anyway.

“So what now Mistress?” the eager white unicorn asked, hoping some more submissive act could be given to her, so that she may prove her worth.

“Well first I am going use my double dildo to break your nice little ass...” Mistress explained, and simply willed one into existence, making Rarity gasp in joy, and a little in fear.

“And after that, we are going to make this land into one worthy of my rule. We have the element of surprise, but we cannot underestimate Twilight. I reckon we could pick up her other friends up first, what do you think?” Butterfly elaborated, penetrating her slave with quick decisive thrusts.

“I... Only... Think... Of... You...” Rarity replied, trying to contain her arousal just so the Mistress starts pushing harder.

“Clever girl.” Butterfly concluded, and gave her slave what she wanted.

She can always decide tomorrow, and what she decides, the rest follow.

Author's Note

Well, well, well... Dark magic? Check. Evil Flutters? Check. Corruption with mind control? Hell YES.