Nightmare Rarity smiled as she made her way down the stairs to her “special” dungeon. Things were going quite smoothly, four of her five friends had surrendered to the darkness, and now only Twilight remained… however as much as she wanted to hunt her down right then and there, family came first. And her sister had waited for her long enough, it was time she accepted the darkness just as her friends had…. but she would make sure that her transformation was one to remember. Her little sister only deserved the best in life…. even if she didn't realize that just yet.

And she reached the bottom of the stairs, she approached a large steel door, upon undoing the locks and opening the door, she could only lick her lips as she approached the creature before her. “Hello darling… ready to greet my sister?”

Sweetie Belle groaned as she slowly regained conscious. "W-Where am I?" She asked quietly, the last thing she remembered was being smothered by the Plundervines, and her mind was still a bit dazed from said events. As she looked around, she realized that she was on a canopy bed in somepony’s bedroom.

’W-Why am I in a bedroom?’ She thought as she hopped off the bed and explored the big room, with windows covered with dark drapes close to the bed, a fireplace across from said windows, its flames glowing an ominous light blue, and yet the quality of the room held an odd welcoming atmosphere...

As she cleared her mind, she remembered Pinkie Pie betraying them and asking her to join her older sister's empire, witnessing Applejack being.... taken by the Plundervines while Applebloom was being held captive, and she herself being trapped in the cocoon made from the Plundervines. She overheard her best friend and Applejack arguing against Pinkie Pie while being violated, and finally her sister ordering Pinkie Pie to take her to her empire before everything went dark...

Sweetie Belle shook her head and glanced at the door to her left. ’I need to get out of here and find Applejack & Applebloom!’ She thought as she galloped towards the door. She opened it with her magic, but the moment she entered the hallway a spell automatically teleported her back in front of the canopy bed and shut the door. "What the-?" Sweetie Belle's eyes derped after the spell and she immediately tried again a few times, but her attempts were met with the same results. “Darn it! There’s gotta be someway out of here!”

"Hello darling..." She heard a voice call out, startling her and sending chills up her spine. The curly-maned unicorn looked around nervously, trying to pin-point the source of the voice. "Who's t-there?” She trembled as she slowly realized who the voice belonged to. “Sis! Is that you?”

At first there was no response, but a few moments later several clouds of darkness begin to swirl around her, slowly becoming more and more solid until it took the form of her big sister. As Nightmare Rarity appeared right in front of her, she cackled as her little sister cowered in fear, the Queen’s evil laughter echoing throughout the bedchambers. "Welcome, dear sister. It's been awhile since the last time we've seen each other. I do hope the Plundervines didn't hurt you my dear." Rarity smirked as she circled around her little sister. Sweetie Belle gulped as she stayed perfectly still, she felt like a mouse under the gaze of a hungry tiger. "My, my, Sweetie Belle, you look simply smashing. It seems you grew into a fine young mare since the last time I saw you." As her older sister licked her lips.

"W-What is this place?" Sweetie Belle blurted out, her elder sibling giggled as she began to stroke her mane, earning a shudder from her little sister.

"Why darling, you're in my bedchambers of course! I ordered my dear friend Afterparty to bring you to my room."

"Afterparty? You mean… Pinkie Pie? Wait, what happened to Applejack and Applebloom?!"

Nightmare Rarity stopped stroking her mane and trotted a few feet away from her. "Well Sweetie Belle...they surrendered to the darkness, just as the rest of our old friends have." She said seductively, turning towards her with a smirk at the last part.

Sweetie Belle’s eyes widened as she tried to hold back her tears. "What!? B-But, they would never...why sis… just... WHY?!"

"Oh Sweetie Belle. I simply helped them embrace the power they so desperately refused. Once they saw its true potential, they surrendered willingly." Rarity said as she went back and comfort her sister. Sweetie Belle didn't show any resistance, too shocked by this revelation to respond. After some thought, Rarity placed her hoof around her little sister’s back. "Darling, don't feel so sad. After all I'm here for you."

Sweetie Belle suddenly broke away from her and galloped towards the balcony, only to discover that she was hundreds of feet above the ground. “No…. no, no, no, no!!” She stuttered.

Her attempt to escape surprised the Nightmare Queen, but she composed herself, knowing there was no way for her little sister to escape. “That was...unexpected. But no matter, there’s no point in escaping darling.” She told her with a stern tone as she trotted over to the balcony. “I’m not letting you get away this time...”

“Please! Let me go! Please…” The younger unicorn cried as she backed away from her until her rump hit the rail.

The elder sibling simply shook her head as she trotted closer, ignoring her pleas as she picked her up with her magic. She then brought her sister to eye-level with her, looking her sister directly in eyes with a serious glare. She was quite tempted to hypnotize her with her eyes like she did to Fluttershy, but she held herself back, her face relaxing slightly yet showing no emotion. “You may fear me little sister, but you don’t have to be afraid. I’m here to help you. I’m going to “share” something with you, something blissful that will make sure you’ll no longer have to fear the darkness....”

Sweetie Belle cried as her sister continued to stare at her, tears were trailing down her cheeks and fell onto the floor of the balcony. ‘Why? Why does my older sis want to ruin everything?! My friends… my family… they’re all gone… consumed by the shadows... I have nothing now…’

Nightmare Rarity continued to stare at her sister for a few moments, as if awaiting her answer, a small smile appeared on her face as her sister stopped struggling, evidence that Sweetie Belle had completely given up any hope of escaping. “Now my dear sister, don’t be sad. This will be for the best... now let’s go back to my bedchambers, sister. It’s cold outside and I don’t want you to freeze.”

Sweetie Belle simply nodded in response, however as Nightmare Rarity brought her back inside, she could've sworn she heard something and glanced at one of the clouds... which was oddly closer to the balcony....

Nightmare Rarity set her sister down on the bed and sat next to her, the younger sibling still crying as she stared at the fireplace. Despite her older sister sitting next to her, she didn’t flinch nor show resistance like she did earlier. The Queen didn’t talk for a few minutes, allowing her sister to recover from her traumatic experience.

After a few more moments she eventually broke the silence. “Sweetie Belle, don’t think of me as a tyrant. I don't just terrorize ponies, I could also give ponies special gifts… provided they serve me of course.”

Sweetie Belle looked her older sister in the eyes for a moment, then looked down. "B-But what about our parents sis?"

Nightmare Rarity paused for a moment and replied. "Sweetie... they'll​ be spared, why do you think I never attacked them in the Smoky Mountains?” Nightmare Rarity asked as she and begin stroking Sweetie Belle's mane.

'She… she knew where they were and didn't attack them?’ Sweetie Belle thought, shocked that her tyrant of her sister still had a shred of mercy within her. The younger Unicorn shuddered by the touch of her elder sister, but surprisingly she started to feel more comfortable. At first she really wanted to get away from her evil sister, but now…. something was keeping her here. 'You haven't seen your sister in awhile….’ A small voice said from the back of mind. ‘You must have so many questions for her. She's already shown that she won't hurt her family, why not catch up with her?’ The voice continued, it's gentle tone sending waves of relaxation through her body.

"Sweetie Belle, I can teach you many things with my powers, things that our parents wouldn't ever allow.” Nightmare Rarity continued, her tone becoming seductive once more.

Sweetie Belle snapped out of her thoughts and curiously looked up to her. "Like... what, Rarity?"

Nightmare Rarity giggled and she took her little sister to a three-sided mirror next to the closet. "Come Sweetie Belle, look at your beautiful self in the mirror." Nightmare Rarity said. Hesitantly, Sweetie Belle trotted to the mirror and stared at her reflection.

"I...look...beautiful?" The teenaged mare repeated.

"Well of course you do darling! You can easily seduce any stallion with such a... desirable body." Nightmare Rarity giggled, causing her younger sister to blush a bit at what Rarity just said, unaware that her older sister was silently ogling her backside.... until she noticed Rarity's line of sight via the mirror and blushed even more. "Trust me darling... you look fabulous!"

“T-Thanks?" Sweetie Belle said nervously.

Nightmare Rarity snickered at her reply and stood in front of the mirror as well. "Now Sweetie Belle, it's your turn to admire me." Nightmare Rarity​ said as she began posing seductively for her sister. “Like what you see, darling?” Her older sister asked. Sweetie Belle couldn't bring herself to respond.... and yet for some strange reason, she couldn't look away.

‘What is she up to? Why is my sis keeping me here? And… and why is she doing such... seductive poses?” She thought to herself, however she was snapped out of her thoughts when she felt her sister's tail casually caress her cheek. “Y-you look... v-v-very pretty...sis.” She replied, a small part of her mind wasn't sure she meant that in a platonic sense or… a sexual one...

“Why thank you darling! I actually have a special pose that I’ve been saving just for you little sister. Wanna see?” Without waiting for her response Nightmare Rarity simply turned around, proudly displaying her backside and marehood to her sister.

“S-Sis!” Sweetie Belle gasped as her eyes widened, Nightmare Rarity’s majestic flank was practically bigger than her face! 'Wait, majestic? Where did THAT come from?!'

“Now, do you ‘really’ like what you see darling?” Her older sister teased as she began wiggling her rump.

‘No… this is wrong…’ She thought as she tried to look away, but her sister used her magic to keep her head in place.

“It’s alright darling. You’re welcome to stare at my majestic flank as long as you like...” She giggled as she continued to wiggle her rump.

“Sis...oh…” Sweetie Belle’s whimpered, her voice softening as she started to feel something building up inside her, her mouth dropped open as she started to drool. As she continued to stare at her plot, lustful ideas started to form in her head, ideas that her parents would've never approved of...

Nightmare Rarity giggled at her little sister’s expression and continued teasing her for a few minutes. She eventually moved her rump out of Sweetie Belle’s gaze. It was only then Sweetie Belle returned to reality, realizing that she'd been drooling and her marehood was starting to leak. She blushed and immediately turned away from her sister, feeling embarrassed and humiliated in front of her. “Oh my darling, you’re getting quite aroused, aren’t you?” She giggled as she turned her back around with her magic and pressed her forehead against Sweetie Belle's. “Trust me sister, you’re going to love what I’m about to bestow upon you….”

Before Sweetie Belle could ask what her big sister meant, Nightmare Rarity kissed her full on the lips, licking up some of her drool as her little sister's body tensed in shock. She tried to pull away at first, but after a few seconds she eventually relaxed into the kiss. However despite her obvious enjoyment, her mind was still conflicted. “Sis...please…..mmhmm…..” She whispered after Nightmare Rarity broke the kiss. “Sis… we can’t. We’re sisters…..we…..” She tried to protest, however Nightmare Rarity simply placed a hoof to her mouth.

“Shhhhh….hush my dear…” She cooed as she kissed her once more, pouring a small amount of saliva into her mouth.

Sweetie Belle’s logical reasoning and need to escape was quickly dissipating, easily being overwhelmed by her sister’s seductive manipulations. 'I....I always thought of my sister as a monster, just like everypony else. But now…. now I’m starting to think otherwise…. they don’t know my sis… not the way I do…’ She thought to herself as she continued to kiss her sister, their tongues battling for dominance between each others mouths, although it was a battle she was losing due to her sister’s tongue being longer than hers. Her marehood was now dripping wet, she felt the need for something inside her...

They eventually broke the kiss, leaving a trail of saliva between them. “You enjoyed that, didn’t you?” Her older sister smirked, Sweetie Belle smiled softly and nodded. “But the fun doesn’t stop there…” She continued as she made her way to the canopy bed, using her magic to carry Sweetie Belle to her once she was close enough she turned her around, getting a good look at her flank. “Oh sister...your flank is so cute!” She giggled, much to her a little sister's embarrassment. “...but it’ll do.”

“What do you-OH!” Sweetie Belle gasped as she felt her sister drag her tongue across her cutie mark, the beginning of her assault on the teenaged unicorn’s marehood. “Sis...wait! I’m still a virgin!”

“Oh don’t worry darling…” Nightmare Rarity replied in a sultry yet sadistic tone. “I’ll be...gentle…..”

And with that she began tracing her tongue around Sweetie Belle’s plot… and soon coming into contact with her pussy. “Ah...AHHHHHHHHHH!!!” Her younger sister gasped, her eyes widening as her face turning red as she felt her older sister’s tongue pleasuring her.

Nightmare Rarity giggled as she traced her tongue around Sweetie Belle’s marehood. “You like that, darling?”

“Y-yes...sis…..please don’t stop.” Sweetie Belle moaned.

“Oh but dear little sister of mine... you need to pleasure me first.” Nightmare Rarity replied and stopped teasing her plot. She then used her magic to lower her sister onto the bed, laying her down on her back. “Oh but don’t worry darling…” She continued. “As a reward I'll not only pleasure you, but I'll make you more powerful and exceptionally beautiful that you ever dreamed of. Besides, you are my sister, we should be together darling. I went through a lot of experiences throughout the years, and I really want to share them all with you...”

“But sis…” Sweetie Belle replied in a nervous tone. “...I’m still scared...”

When her older sister heard this, she grinned. It was all going according to plan. “Darling, you don’t have to fear the darkness. There is a good side to it, and I’m going to share it with you, like how Afterparty shared it with Applejack and Applebloom.”

“Sis…. how did they embrace the darkness?” Sweetie Belle asked, although deep down she knew what was going to happen in a few moments.

“You’ll soon find out...sister.” She smirked, it was then that her sister stood over her, lowering her rear very close to her face, to the point where Sweetie Belle could see her medium to huge breasts. “S-sis! You’re...you’re breasts…” She stuttered.

Nightmare Rarity snickered at this. “Oh, you like them sister? They are wonderful, aren’t they?” She then looked down and had a good look at Sweetie Belle’s. “Looks like yours are smaller than mine.” She teased, Sweetie Belle puffed her cheeks in frustration and slight embarrassment.

“Relax sister, I'm just teasing.” She giggled. “Now then, pleasure me. Do this and I’ll make you squeal.” She commanded in a alluring tone as she sat down on her sister.

Hearing Nightmare Rarity speaking so seductively made Sweetie Belle more and more aroused and wet. She stared up at her sister's marehood, inhaling deeply as she took in its scent, it was so alluring, beckoning and persuading her to come closer. Sweetie Belle consciously obeyed this unspoken command and booped her nose against Nightmare Rarity’s marehood, she then opened her mouth and traced her tongue along the outer lips of her sister’s sweet spot, just like her sister did to her. “Mmmmmmmmmm…yes Sweetie Belle.” Nightmare Rarity moaned, the teenaged unicorn smiled and continued to trace her vagina with her tongue. After a few moments, she went ahead and begin pushing her tongue deeper into her pussy. Nightmare Rarity’s tail wrapped around Sweetie Belle’s head as her young sister licked up all the juicy fluids inside her.

‘Mmmmmmm... my big sis tastes so good!’ Sweetie Belle thought as she licked her pussy, the scent and her own arousal easily banishing any thoughts of escape from her mind. Gone was the voice that told her that her sister was still an evil monster, instead she started to see her sister as a guardian, someone who would protect her, guide her, and most importantly of all; pleasure her.

“Yes, yes, yes Sweetie Belle! Just like that!” Nightmare Rarity squealed as she pushed her body against her sister’s, her sister’s neck now sandwiched between her breasts. Due to her weight it warmed Sweetie Belle’s body up, which made her feel more comfortable. Nightmare Rarity used her tail to push Sweetie Belle’s head further into her pussy. Her face and some of her horn eventually became hidden in her sister’s plot. While her older sister shouted with glee, Sweetie Belle just giggled and smiled as she continued to eat her out. “Oh Sweetie Belle, I’m so close!” Her sister moaned, then in a bold move, Sweetie Belle turned her attention to her sister's clitoris and proceeded to give it sloppy kiss, swirling her tongue around it, her sister yelped and rewarded her by unleashing a torrent of cum all over her sister’s face, drenching her coat and mane in her juices.

Sweetie Belle felt an odd sense of euphoria as she happily licked some of the juices off her face, at this point most if not all of her resistance have been thrown out the window. She never wanted this feeling to stop, and she would please her sister and anyway she wanted. 'Everypony is wrong. My big sis just wants everyone to embrace the darkness… to see how wonderful it is, how much pleasure it can bring…’ She thought to herself.

“Oh Sweetie Belle…” Nightmare Rarity smiled seductively, having finally caught her breath. “...you were amazing.” She giggled as she lifted her rear and looked back at her with hungry eyes. “You have done your part, now I’ll return the favor.” Nightmare Rarity giggled as she got off of her sister and used her magic to flip her over, pressing her face against the pillow while lifting her rear into the air. However instead of just tracing her vagina like she did earlier, she just started dragging her tongue up and down. Sweetie Belle gasped and began to moan as she once again felt her sister’s tongue assaulting her. Nightmare Rarity then prodded her muzzle onto Sweetie Belle’s pussy and pushed her long tongue in and out of her marehood.

“Ohhhh….sis…” Sweetie Belle moaned in pleasure.

Nightmare Rarity giggled at her response as she continued to swirl her tongue around the inside of her pussy. 'I’ve been waiting for this for a long time, dear sister… just wait, soon you’ll be mine and become the new Princess of the Night, alongside me, your- beloved Queen...!’ She thought as a seductive grin spread across her face. She then pushed her lengthy tongue even further into Sweetie Belle’s pussy, resulting in her breathing becoming more accelerated as her older sister pleasured her. “Oh...this feels so good! Oh yes!” She moaned loudly, her cries of pleasure echoing throughout the bedchamber.

Nightmare Rarity grinned at this as she continued to lick and slurp up Sweetie Belle’s juices. “Oh darling...you taste divine.” She cooed.

“S-Sis...I’m…something...is building up...it’s-ohhh…” Sweetie Belle gasped.

“Yes little sister...just let it all out...and-” Nightmare Rarity was cut off as her sister let a out a strained moan and had her first orgasm, her juices spraying all over Rarity’s face as she squealed pleasure. Nightmare Rarity simply drank in her sister’s love juice, relishing the tangy flavor. Sweetie Belle looked down at her sister and smiled despite the fatigue she was feeling.

“Feeling tired Sweetie Belle?” Nightmare Rarity cooed “Oh darling, the fun isn’t over yet.” She lifted her up again with her magic and laid her down on her back before sitting in front of her and spreading her hind legs apart, exposing her magnificent marehood to her little sister. The elder sister then pulled Sweetie Belle's hind legs apart, exposing her marehood as well. “Don’t fret, I've got something that'll replenish your energy, but first....” Nightmare Rarity replied in a sadistic tone before she then pressed her younger sister’s pussy against her own, rubbing their marehoods together and earning another gasp of pleasure from Sweetie Belle.

‘Ohhh… this feels so amazing! Why didn’t I ever do this with the other Crusaders!?’ She thought to herself as she felt a familiar build up once more, only for her sister to suddenly stop pull Sweetie Belle away with her magic, much to her disappointment. “Oh darling… that was so divine! We should do this more often after I corrupt Twilight.” She said seductively.

Hearing Twilight's name briefly brought her back to reality. “H-huh? Twu-Twilight....?” Sweetie Belle replied in a daze.

“Of course darling. We need to make sure all of our friends embrace the darkness.” Her older sister responded and she laid down next to her canned gave her another kiss. Sweetie Belle briefly hesitated, but quickly started to relax and kiss her back. “But of course, you must continue your “coronation”…” She as she broke the kiss. “And to do that we need a few more friends for our ceremony… oh darling~!” Nightmare Rarity called out in a sing-song tone.

Sweetie Belle arched a brow at this, wondering who she was calling, however her silent question was answered when she heard the door opening, her sister seemed more eager and excited than ever as a tall figure stepped into the room. As she took in the appearance of the new arrival, she noticed something distinctly familiar about him… then the figure stepped into the moonlight, allowing her to see him properly…. and her jaw dropped when she realized exactly who was standing before her.

“SPIKE!?”

Author's Notes:

IT'S ALIVE!!!

Special thanks to rainbowdash161 for helping bring this story back!