Author's Notes:

This chapter prompt was suggested by nfreak as part of my Patreon-funded project, and contains themes involving Rainbow Dash, gender dysphoria, and transgender-based content. It's rated NSFW due to slight sexual content, but is not pornographic or fetish-based.

As soon as that recorded scene was locked away alongside Spike’s coming-out moment, Starlight had gotten her energy back following that impromptu teleportation of Sunburst back to the Crystal Empire. Twilight Sparkle was a little confused about the stallion’s hasty departure, but she couldn’t necessarily keep the Royal Crystaller from leaving when he was needed for “a top-secret emergency.” She had no idea what it was, but she was fairly certain it had something to do with that orb of magic. However, she wasn’t able to learn much when Starlight kept a tight muzzle about the matter, and no recording could be found in the orb that was relevant to Sunburst’s leave.

The Princess whinnied in slight annoyance as she stood beside Starlight in the hidden room alone. She was tempted to just order her student to spill the beans, but she knew better than to use her Royal status to compromise her friend’s trust in her. Plus, given how controversial the magic orb was, she had a feeling if Sunburst’s emergency exit was related to it, she was better off not knowing too much. Nevertheless, the Princess was still frustrated enough to groan under her breath as she glanced up at that blasted orb. “So… just to clarify, Sunburst’s leaving is related to a Pinkie Promise the two of you made?”

“Yes,” stated Starlight almost instantly, not wanting her mentor to learn any unneeded knowledge about her older brother. There may have not been any official Pinkie Promises given between her and Sunburst, but she was quick to say in an insistent tone of voice, “I have absolutely nothing to say on the matter, and I am not related to him leaving in any way.”

Starlight’s firm and unwavering tone was beyond suspicious, but Twilight merely skewed her muzzle as she stared back at her protegè. Despite how much the unicorn was sweating through her stoic expression, Twilight took a second to close her eyes and exhale through her nostrils in defeat. “Well… alright then,” she said with a very reluctant sigh before deciding to drop the subject. “I won’t try to ask and risk breaking a Pinkie Promise. Just as long as it isn’t anything dangerous or threatening to Equestria as a whole, okay?”

“Okay,” replied Starlight with an unbelievably strong exhale in relief. She had to turn away from the Princess for a moment as she caught her breath, obviously having held it before Twilight gave that kind of answer. She held a hoof to her chest as she nodded, and eventually looked up at her mentor to say truthfully, “A-And believe me, it’s not… I mean, I’m fairly certain it isn’t anything like that.”

Twilight may have known that Starlight was keeping something big under wraps, but she was still reeling over that Fluttershy recording to try and argue with the unicorn at that moment. “Well, alright then,” she said with a shrug, before she turned her attention back to that magic orb.

Starlight seemed surprised when she saw the Alicorn light up her horn, and cast an activating flash upon that dome of magic. “Wait, you… you’re wanting to see something else?” she asked while blinking a couple times in puzzlement. “I… I kinda figured after last time, you woul--”

“Well, I can’t exactly leave this experiment unchecked while Sunburst is temporarily absent,” replied Twilight in interruption. Her expression remained brooding for a moment, before she closed her eyes to take a calming breath. “Also, I… I happen to know for a fact that Fluttershy is visiting her family today, so it’s doubtful I’ll be seeing her in this spell again.”

“Oh, ummm… okay then,” said Starlight with a shrug of her shoulders. By the time Twilight was looking more well-composed, the unicorn decided to add with a positive tone of voice, “Well, hopefully Sunburst will be ready enough for me to bring him back by tonight. So even if we do see something freaky, he can take over fairly soon.”

The Princess’ muzzle was wrinkled with an unconfident scowl, but she was able to process her student’s point enough to faintly nod in agreement. “I… I suppose that is true.”

“There you go!” despite the Alicorn’s political ranking, Starlight was comfortable enough to give her a playful punch on the shoulder. “Seriously, you need to lighten up a little! All that’s important is that everything is fine, alright? Our research is going well, Sunburst will be back tonight, and we’ll all hopefully learn more about friendship by the time the week is through.”

Just as the screen began to appear within that magic orb, Twilight looked back at her friend with a weak, but still notable smile on her face. “Well… hopefully we will, Starlight Glimmer. Hopefully we will…”

The scene that appeared on screen was fairly dark at first, but the two were quickly able to realize that this spell was being recorded deep within the realms of the Everfree Forest. Although strangely enough, the view didn’t seem to be nearby Zecora’s hut, or at the Castle of the Two Sisters. Instead, Twilight and Starlight saw a serene-looking clearing that held a beautiful blue pond. A thick line of trees bordered along most of the pond’s outline, but there was a grassy section near one end that was beside a faintly-treaded trail. And before too long, a peculiarly unique pony trotted out from that trail to stop by the clearing with a smile on her face.

“Aaaahhhhh…” With a relieved sigh escaping her muzzle, Rainbow Dash seemed fairly happy to be by herself in such a secluded region of Equestria. Given how large the mare’s ego usually became when she was surrounded by other ponies, it seemed odd that she appeared so content being alone in the Everfree Forest of all changes. However, Twilight and Starlight stayed silent as they watched the screen, and saw their friend reach into the large satchel hanging over her shoulder. As she rifled her hoof around the inside, the pegasus’ lip was slightly bitten while a small blush began to appear across her cyan muzzle.

“Hmmm… darnit, where did that bottle go?” Dash muttered under her breath in slight annoyance. Even though she was in a rather private location, it seemed like she was eager to find whatever it was she had in her bag. Fortunately, her face lit up as she caught sight of the item at the very bottom of her satchel. It was then that she pulled out a small, ornate glass bottle filled with an oddly glowing blue mixture; neither of the mares watching knew what it was that Rainbow Dash had, but they were certain that the pegasus paid a visit to Zecora in order to obtain it.

Dash also pulled out a small parchment that came along with the bottle, and then took off her bag to lay on the ground near her hooves. After looking around cautiously to ensure no glowing eyes were peeping in on her, Rainbow breathed out calmly and read through the instructions the zebra wrote for her. “Okay, let’s see…” Her magenta eyes narrowed on the uniquely scrawled text, which was just as poetic as Zecora’s method of speech. “... This bottle contains one dosage to take, but be sure before to give it a shake… Effects will show in less than a minute, and lasts one hour when you begin it…”

Rainbow blinked a couple times, and grew an offended look upon re-reading that last line. “ONE HOUR?! I spent two hundred bits on this!!”

The mare groaned angrily as she looked at the bottle in her other hoof with a scowl. However, she took a moment as she gazed at that shimmering liquid, and eventually sighed in reluctance as she shook her head. “Ughhh… Hopefully this’ll be worth it…”

Rainbow still looked peeved, but she tried to keep her emotions in check while reading the rest of Zecora’s directions. “... You may feel like that is not enough time, but… hopefully the effects feel sublime. Once you experience a form anew… You will know what the next step is for you…”

The pegasus’ lips were tightly pursed after finishing Zecora’s notes, clearly needing a second to let those rhyming words sink in. After closing her eyes with a more tranquil sigh, the pony put down that parchment while her expression turned slightly uneasy. Dash looked back at that tiny glass bottle, and didn’t say anything for a notable amount of time. But after breathing out through her nostrils, Rainbow closed her eyes and said with a clearer tone of understanding. “A-Alright then. I… I guess this is the only way to know for sure, right?”

The mare seemed hesitant at the last second, but her face scowled as she quickly shook her head clear. She took one last breath while her eyes were tightly shut, and then reopened them to give a sterner stare at that bottle. “Okay… it’s only an hour, so… so hopefully this’ll do it for me…”

Before she could get any last-second thoughts, Rainbow Dash shook that bottle in her hoof as rapidly as she could. Like a glow-stick, the illumination of that blue liquid intensified as the chemical compounds reacted strongly to her agitation. Rainbow stopped shaking after a few seconds, and uncorked the lid of that bottle with her teeth to spit out. And then with a brief huff, Dash looked down at the opened bottle of Zecora’s mysterious potion with a more determined expression. “Alright then… Let’s do this!”

Rainbow brought up the bottle to her lips, and pulled her head back as she downed that potion like a shot-glass. There was only enough of that blue mixture to elicit two gulps at most, but the taste was still bitter enough to make the pony cough strongly the instant she swallowed the last drop. She dropped the bottle as she lurched forward with a hoof over her chest, hacking violently between her strained gasps. At first, Twilight and Starlight grew worried that their friend was having an allergic reaction to the contents of that bottle; however, the instant Dash was able to breathe clearly again, it became obvious how effective that potion really was as its illumination returned.

As the mare breathed heavily with her head hung low, she wasn’t able to notice her cyan fur glowing while her eyes were tightly shut. However, it seemed that she was able to feel the potion working as she grunted with a sharp arching of her back. Rainbow cried out with a loud yelp as she winced, and her hooves gripped the grass below like her nerves were burning painfully. But despite how much her fur was standing on end from the effects of what she consumed, she gritted her teeth tightly as her muscles began to contort beneath her glowing fur.

The two mares could only watch as they witnessed the slow, but shocking transformation of their friend through that magic orb. While the pegasus grunted between strained breaths, her body began to change in ways Twilight or Starlight would’ve never envisioned. Rainbow’s muscles rippled outward like the wavelength from a bomb within her, stopping only at the very base of her hooves. But instead of settling back to those thin, delicate hooves Rainbow used to have, they expanded out slightly to carry a thicker, more masculine form; after that, tufts of fur began to grow out around the sides of Dash’s keratin, giving the pegasus fetlocks along those hooves to add to the burlier physique.

Slowly, the rest of Rainbow’s legs grew out and expanded to add more muscle mass. The pegasus’ fur started to appear more coarse as well, thickening around various regions and growing outward to conceal that once slender form. As soon that the muscle contortions came up to Dash’s torso, the changes grew much more evident while the pony grunted hard. However, Twilight and Starlight were able to notice that their friend’s groans were slowly sounding deeper as the changes intensified.

Regions that were once thin and feminine grew out to be covered in muscle and a thicker coat of fur. Rainbow’s bright cyan coat started to deepen ever so slightly, carrying a darker shade which seemed more fitting to a male than it did a female. The pony’s technicolor mane didn’t change in hue or tone, but it began to shorten as it sunk back inward against the scalp. Soon enough, that frizzy rainbow mullet became something more akin to a stylish crew-cut along the sides while the top remained spiked and stylish. Meanwhile, Dash’s pained groans grew louder as their muzzle opened wide, and the length of it expanded out a couple inches.

Before too long, it became obvious that the pony grew noticeably larger due to the added height and muscle mass they gained from the potion. However, even as the pegasus grew more masculine by the second, all of Dash’s other changes were quickly overshadowed by what was happening between those muscled rear-legs. The smooth, petite marehood that the pony once had started to contort and change, much to the surveilling ponies’ shocks. Rainbow’s tiny, supple button of a clitorus expanded out significantly, and began to take a new form as it grew outward. Neither of the mares were able to accurately ascertain the process as it quickly melded from one step to the next without pausing, but it was obvious what was happening by the time that organ turned into a familiar… but still unfamiliar appendage.

“.... Mmmmnnnnnghhhhhhh…” It took about a minute or so for Rainbow to come down from the intense, spine-tingling convulsions those nerves and muscles experienced at such a rapid pace. The pegasus’ breathing was still heavy by the time they finally reopened their eyes, unsure how effective that potion was without a mirror to see. If Dash were able to see through that magic orb back at Twilight or Starlight, they likely would’ve seen two dropped jaws alongside their stunned expressions. But alas, that spell was thankfully invisible to the pony as they awkwardly moved over to the pond instead.

The pegasus paused for a second before they would see the reflection, needing a moment to think over what they might see staring back at them. But after one last, shivered breath in anticipation, the pony leaned forward to see their face for the first time. Rainbow’s eyes grew as wide as saucers, and they could only stare in frozen silence at the sight of that stallion peering back through the water. By all intents and purposes, the pony still looked remarkably close to what Rainbow Dash used to be; except now, the most obvious difference was clear as day while the pony looked at their reflection in utter awe.

“I… I’m…” Rainbow’s muzzle clenched shut for a moment, not expecting such a deeper voice to come out of that masculine muzzle. A fetlocked hoof came up to press against it, only to make them look down at that as well. After a while, the pony stepped back from the pond to marvel at just how different their body appeared now. Tears began to bead at the corners of Dash’s eyes, but their muzzle wrinkled up into a trembling smile while panting shakily. “I’m… I’m a…”

That voice still sounded so alien, but at the same time, it was comforting enough to make those tears of joy start treading down Dash’s cheeks. The pegasus’ smile widened immensely by the second, making them look very similarly to how they felt when Spitfire first inducted them into the Wonderbolts. But this time, the change was much larger than any job or title they could’ve possessed. After taking a deep breath, the pony looked back down at themself and uttered in the briefest creak. “I’m a… I’m a stallion…”

Upon saying that word out-loud, and knowing it was actually true, the pony sobbed with a hoof over his mouth. More tears began to run down his face, and it took everything in him not to start crying in absolute glee. He rushed back towards that pond, and stopped just at the edge to get a better look at his new body. Rainbow’s smile was as wide and genuine as it could’ve possibly been, and several more breaths came out rapidly before he started prancing in place. “I… I’M A BUCKING STALLION!!!~”

It was then that the pegasus shot up from the meadow to break through that foliage into the untamed skies, shrieking in utter glee while flying in his new and larger wings. Rainbow faltered a few times due to his brand new body type (as well as the Everfree Forest’s unchecked wind-directions), but it didn’t look like he could care less while soaring with an unbreakable smile and tears beading off his face. The pony gilded around at breakneck speeds for five minutes straight while crying out to the heavens, shouting with absolute elation about what he knew to be. “YEEEEEESSSSSS!!! I’M A GUY!!! I’M FINALLY A GUY!!! Sweet… SWEET CELESTIA YEEEEESSSS!!!~”

Meanwhile through that magic orb, Twilight and Starlight were both completely silent as they watched with their forelegs over each-other’s shoulders. Both of them were crying, but it was obvious that they were tears of pride as they smiled just as much as Rainbow was. While most ponies would’ve treated a temporary gender-swap as something for fun, or maybe even comical, it was crystal clear how much it meant for the stallion flying around with such a look of blissful realization on his face. Neither of the mares would’ve ever fathomed the idea of witnessing such a moment, especially from one of their friends, but it was something both of them knew they would never forget.

Eventually, the newly-reborn stallion landed back down in that clearing to catch his breath, as well as to wipe his face. But alas, he was still breathing in hiccuped huffs as he tried not to keep crying in joy of what he was experiencing. His eyes couldn’t stop looking down at his masculine hooves, or at the reflection of himself in that pond. While he wished he brought himself a mirror beforehoof, that wasn’t too big of a problem as he began to pace around the grass while talking to himself. “I… I can’t believe it! Af… After all these years, I… I can really say it now…”

He stopped briefly to catch his breath, and carry a content smile on his face as he took a deep breath. “I’m… I’m actually a male…”

The stallion began to tear up again after that statement, but his smile never went away as he looked back at his temporary new body. “Oh, man~” he said with an elated squee while stepping giddily in place. “I… I really gotta get more of that stuff from Zecora!~ Or… Or uhhh…”

Rainbow paused his thoughts as he turned back forward, and grew a more studious look on his face. His hoof came up to scratch at the top of his much shorter rainbow mane, and he thought things over a bit before taking a breath. “Ho boy… I… I have a lot to think about, don’t I…”

The pegasus bit his lip, realizing that this confirmed everything he was considering over the years. But now with the realization of his true gender clear as day, that meant he had a lot to prepare for in the near future. He huffed as he glanced back down at himself, his muzzle skewed slightly in growing discomfort. “Ooooohhhhh… this is going to be a big thing to tell my friends about…”

His muzzle pursed shut as he stayed silent for another minute or so. While he didn’t look necessarily scared or worried about his future, he seemed to appear a bit awkward about what he had to do. Of course, given how strenuous coming out and transitioning can be, even an Element and Wonderbolt could feel that pressure seeping in like a thick veil.

However, before he could try and really process how much he would need to change things around for himself and his friends, the pony decided to just shrug with an indifferent look on his face. Since there was plenty of time to think those things over after the potion wore off, his attention quickly turned to a more pressing issue he wanted to tend to now. The stallion quickly sat himself down in the grass, and took a breath before spreading his hind-legs apart wide in front of him. His blush deepened immensely as he looked down at that twitching, half-flaccid member that was quickly slipping from his sheath. As the thick, marbled shaft grew inch by inch before his eyes, he shuddered with a giddy grin before saying to himself, “Ohmigosh… Ohmogish that’s a penis… That… That’s…”

His smile grew wickedly wide before he said with a shaky exhale, “That’s… That’s MY penis!!~”

Despite his new body, Dash still giggled like a school-filly with his hooves over his mouth. “Oh, man~” he squeed as he fanned himself with his hooves in anticipation. “I can’t wait to actually jack off! Ohmigosh, this is SOOOO awesome!~”

Rainbow couldn’t wait to get started, and enthusiastically brought down one of his hooves to grip his growing shaft. Unfortunately, due to his lack of experience and the speed of his velocity, his meaty hoof came down hard as it landed squarely against a region directly below his cock. Instead of getting a good grip at the base of his erection, Rainbow Dash tensed up with a frozen look of utter pain the instant he accidentally hit himself in the balls. “NNNGGGGHHH!!”

Dash remained frozen in his position for several seconds, his eyes widened hard while his pupils shrank to the size of pins. His smile was welded onto his muzzle, but it was accompanied by a high-pitched whinny that was coming out like the faint whine of a furious mosquito. Due to never experiencing a nutshot until that day, it wasn’t too surprising that the pain would be intense enough to make the pegasus fall over onto his side. Even though he still had the rest of the hour to be acquainted with his new body, the pegasus was writhing in absolute agony as he let out a helium-like groan with a shudder.

“Oh… Oh GODDESS that hurts…”

There was probably much more to be recorded from that scene, but Starlight would never know the result as her mentor prematurely stopped the scene from playing on the orb. Much to the unicorn’s shock, Twilight Sparkle used her magic to get a firm grip on that screen and pry it from that magic globe. Much like the ones Starlight confiscated, a pure white ball of translucent energy was hovering in the Alicorn’s aura the instant it was pulled out of that orb. Inside of that ball, a faint reflection of Rainbow Dash could still be seen squirming inside of it.

“Twilight, what the heck!?” shouted Starlight in stunned surprise. “What did you stop that recording for?!”

“Because we can’t use this for our studies, Starlight,” stated the Princess firmly as she stared back at her with authority. After wiping her cheeks dry with a hoof, Twilight took a quick breath before explaining, “When I started this experiment, it was with the intention to record ponies to better understand friendship and relations between ponies. NOT to pry in on ponies’ personal lives or intimate moments.”

Even though she already knew that, Starlight couldn’t help shrugging as she said, “Uhhhh… it’s kinda late for that already, isn’t it?”

“You know what I mean!” retorted Twilight sharply. She held the ball up higher in her magic as she added in a stern tone, “Starlight, this is an extremely personal moment that we just witnessed without Rainbow Dash’s consent. If we were to keep this, we would be risking destroying the trust of one of our closest friends! If our friend learned we had that recorded, Dash would NEVER forgive us. Do you understand that?!”

Even though she felt like that recording could be important to keep (especially if Rainbow Dash wanted a memory of how they felt in that moment), Starlight knew better than to go against the Princess’ truthful point. Considering how Rainbow was the Element of Loyalty, even the former villain knew that keeping that ball could endanger the pegasus’ trust in them. It was bad enough that they accidentally witnessed Dash having a private moment regarding their gender dysphoria, but keeping it for the sake of this experiment would’ve been far too low to justify by any means.

“Well, I… I guess that would be a time-bomb waiting to happen,” replied Starlight as she sighed in reluctant acceptance. But before Twilight could do anything to the ball to destroy the evidence, the unicorn felt like adding, “But! Ummm… could at least try to do something to help Rainbow out? Like… maybe asking if he wants to talk with us about it?”

Twilight huffed in uncertainty while her muzzle skewed a little. Even though she knew it would be a smart option to let Dash know they have support, it was a tricky process considering how that was supposed to be a private issue. Heck, considering how little she or Starlight knew of Rainbow’s dysphoria, Twilight was wary about changing their usage of pronouns around them just yet. But alas, the Alicorn sighed through her nostrils before she answered with a meager shrug, “Well… I don’t think we should say anything to Dash first, alright? If sh… if they want to talk with us about it, then we should wait until they’re comfortable. We can’t be making any hasty assumptions after seeing one moment they experienced by themself.”

Starlight understood the Princess’ point, and nodded pertly while her muzzle was tightly shut. After taking a deep breath, the unicorn replied, “Okay, I… I guess that’s fair, Twilight. I really do. Although…” She looked away from her mentor feebly before she twirled a lock of her mane around her hoof and asked, “Would… it be alright if I asked them to visit my Guidance Counselor office? You know… just in case?”

Twilight wasn’t too keen on allowing that, but exhaled weakly before she said, “Well… as long as you Pinkie Promise not to bring up anything regarding Rainbow’s gender identity before them, okay? I do NOT want you making them feel uncomfortable, or obligated to out themself too soon!”

“Absolutely!” To further add to her assurance, Starlight Glimmer brought up her hoof and followed the proper hoof movements alongside her plea. “Cross my heart, hope to fly, stick a cupcake in my eye. I promise I will NOT ask Rainbow Dash about their gender identity! You have my word.”

“Thank you.” Twilight then smiled contently as she and Starlight shared a much-needed hug after all they witnessed. After that, Twilight placed the recording down on the ground between them, and stomped on it like a log at a Yak celebration. The ball bursted into a million pieces of luminescent light, which quickly evaporated and dispelled across the floor. As soon as all of the shards dissipated and were out of sight, Twilight sighed and asked her protegè, “So… you wanna grab some lunch in town? I could use some fresh air.”

Starlight Glimmer nodded with a smile of her own. “Sure thing, Twilight.”