"Okay," Twilight said, a notecard hovering in front of her encased in a magenta aura. "Starlight, are you ready?"

"I guess so," Twilight's student replied, an expression of concern on her face. "Why do you keep researching this spell anyway? You've already turned two friends of yours into guys, and that one stallion already came and asked you to make him a girl."

"That was a favor... kind of," Twilight said hurriedly. "It's not important. My friends were part of an experiment, and I'm actually making really good progress on that. I'm about as far as I can get without more field tests though, so I'm putting myself up this time."

"Why you?" Starlight lifted a hoof as if to take a step forward, but didn't move. "Why can't you get somepony else to do it?"

"I'd rather ask a friend than a stranger," Twilight explained, "because asking some mare in the street feels like an abuse of my status as princess. I didn't think Applejack's family would take kindly to it if she'd decided to stay male afterwards, and I really didn't want to push it on Fluttershy. And I really, really didn't want to push it on Rarity." Twilight hesitated. "Plus, it would be helpful if I could understand myself why both Rainbow Blitz and Bubble Berry didn't seem all that interested in changing back, even if Berry did tell me he'll be willing to return to being a girl in a couple days. Even with the subspells intended to help with the body dysphoria and gender identity, I would have expected them to want to change back based on matching their memories and avoiding awkward reactions alone."

Starlight's look of worry didn't abate, but she put her hoof back down. "I still think this is unnecessary..."

"Well," Twilight said, "if I do in fact manage to succeed here, I'll have isolated the process necessary to transmute a pony body from any object, not just clothing. I ran into roadblocks trying to enchant material that wasn't conductive to the enchantments I was using, so I'm testing a workaround. I have a ton of failsafes in this that'll revert the enchantment if it fails a step, so the two most likely outcomes are that nothing will happen or it'll do everything right."

"And why is it a gender flip again?"

"Testing replacements for the section that changes body, identity and orientation won't require an actual field test, so I've saved that for last. Getting the transfiguration to work properly is the hard part; once the proof of concept is there, the rest is entirely theoretical."

Starlight pursed her lips, but didn't say anything, stepping back and grabbing a spherical black stone sitting in a small cup on the table where Twilight kept her notes.

Twilight nodded to her, and her student rolled the ball towards her. Twilight grabbed it with her front hooves, brought it up to her horn so that the two touched, and activated her magic. A tingle of static electricity shot down her spine, and Twilight quickly cut off her magic, rolling the ball back towards Starlight.

As Starlight returned the ball to its place, Twilight brought a hoof up to her face, rotating it as the cup expanded and thickened. Twilight felt her hooves swelling almost like an allergic reaction, but upon further examination discovered that it was really more about how it felt than how it looked.

Trying to ignore the mild disappointment she felt that she would not be gaining Rainbow Blitz's kind of muscle definition, she instead examined her flank as her haunch expanded in size, stretching her cutie mark against her side. She bobbed her tail, watching the hair segment into three separate strips that retracted, leaving her tail shorter. "Not as girly, I guess," Twilight muttered to herself. Feeling a shift between her hind legs, she decided not to dwell much on it for the moment.

Turning back to look at Starlight, Twilight felt her chest twinge as her bone structure widened. She realized that, considering that she was already taller than most of her friends, she'd probably end up gaining at least a few inches in height over all of them. Her spinal column cracked and popped at the thought, stretching her neck to do just that.

Twilight closed her eyes, trying to stay calm as her mouth stretched and her chin felt like it was getting pulled out. The skin around her eyes tingled as well, and she couldn't suppress a grimace at feeling her carefully-styled mane shift and split.

Feeling the magic pushes and pulls on her body subside, Twilight opened her eyes to see Starlight staring wide-eyed at her, cheeks flush and mouth hanging wide open.

"Something wrong?" Twilight asked, before putting a hoof to her throat. Wow, wasn't expecting a voice sounding so much like my brother. His is a little deeper, though.

Starlight didn't respond immediately, blinking before shaking herself. "Holy cow," she whispered. "You're... really hot."

Twilight blinked. "I am?" She could already feel the magic inside her easing her into her own body; her entire head of height over Starlight barely felt weird at all. I wonder if I'm as tall as Cadance now?

"Y-Yeah..." Starlight covered her eyes with a hoof, looking away. "I have to force myself not to stare at you, you're just so..." She trailed off.

"Well, that wasn't an intended side effect," Twilight assured. She reviewed the spell in her head; next was her gender identity. She had wondered how the process had differed between Bubble Berry and Rainbow Blitz.

Thinking about "girl things," Twilight acknowledged that she felt like she was feeling less interested in a number of activities; Spike's "guy's night" didn't sound like it would be as boring to her, even it if were without Discord. Maybe I should ask my brother for his old Ogres and Oubliettes books to see if they interest me now...?

Twilight cringed as the magic pinched briefly in a specific part of his brain. Hold on, his? Yeah, his. Twilight was less surprised about the change than he was at how suddenly the shift had come; calling himself female now felt wrong somehow, even though just a moment earlier it was the only way he'd describe himself.

Now I know why Blitz and Berry correct pronouns so quickly. Next is... orientation. That's why Starlight is here... hopefully. Twilight refocused her eyes on Starlight, who was sneaking peeks of Twilight over her raised leg and blushing madly.

Twilight kept her gaze on Starlight, waiting for something to happen. Twilight began to worry that something was wrong when he didn't notice anything different about how Starlight looked, or how her mane framed her face, or how her eyes glowed in the luminescence of the castle lights, or how her soft, supple flanks gave a nice curve to her backside... Oh.

He snorted, half in amusement and half in trying to rid himself of his more impure thoughts. "I see what you mean when you talk about attractiveness... You aren't half-bad looking either by the way, Starlight."

The object of Twilight's newfound affection eeped, and her face turned beet red. She sat down, covering her entire face with both hooves.

Twilight stepped forward, putting a hoof around Starlight's shoulders. Wow, she's absolutely adorable! How didn't I notice it before? "It's okay, Starlight. I'm not going to hurt you."

Starlight looked up, locking eyes with Twilight for a second before jerking her head back to where her eyes were protected by her forelegs. "I can't even look at you without going crazy, you're just... I can't help but want to kiss you or something..."

"Shhhhhh." Twilight sat down next to her and began rubbing her back. "It's okay."

One last flash of magic ran through the alicorn's head; in the back of his mind, he remembered that it was to change his name, but he couldn't remember it being anything other than Dusk Shine. I'll have to check the records to make sure that part of the spell worked...

"Twilight, really," Starlight said, earning a chuckle from Dusk. Or Starlight could confirm it for me. "We shouldn't play with temptations here. It wouldn't be right."

"What's not right about it?" Dusk Shine asked, genuinely curious. "I'm a stallion, and I'm straight. You're a mare, and as far as I know, you're straight. What's the problem?"

"B-Because!" Starlight squeaked.

Dusk resisted the urge to d'awwww. Still, he probably shouldn't tease too much. "Alright, I suppose it's less difficult for me to consider thanks to the magic at work." He dropped his hoof from Starlight's back, and got to his hooves, taking a respectful step back.

Starlight Glimmer took several slow, deep breaths before removing her hooves from her face, looking at Dusk Shine again. Her mouth wavered, and her blush returned. "So, h-how do you feel, Twilight?"

"It's Dusk Shine now," Dusk said nonchalantly, "and really, it feels normal. I understand what Rainbow Blitz meant when he said it feels like you've always been this way." Dusk ran a hoof across his chin, realizing that he'd probably have to start shaving; even though he felt like a stallion inside and out, there were still some things he'd have to learn about being the opposite gender.

"So... does this mean you're not going to change back either?"

Dusk shook his head. "I want to write down observations and emotional responses on the matter before I did anything else, so I knew I was going to be this way for a while regardless of whether I wanted to change back or not."

Starlight licked her lips. "So... I'm going to have to deal with an alicorn prince wandering around the castle... indefinitely?"

Dusk Shine chuckled again, a full-throated laugh that caused Starlight's hooves to plant themselves right back in front of her face in embarrassment. "I don't know about indefinitely. Like I said, I'd like to see how everypony's reactions affect my viewpoint in all this. Now that I know what it feels like, I'm also honestly interested in the results I might get if I were to remove the dysphoria and identity sections of the reversion spell. But all that's for later. Right now, I need to note down that the test run was a success and take the initial results."

Starlight nodded. "W-Well, I'm just going to go back to my room then. Lots of, um, studying."

"Wait," Dusk said. "Before you go... perhaps you'd like that quick kiss you said you wanted?"

A squeal escaped through Starlight's nostrils, and her horn flared, but not before a magenta aura encompassed the unicorn first.

"Hold on a second," Dusk Shine said, trotting over to Starlight, "I'm actually serious. If you want to, then go ahead. I don't mind."

Starlight's hooves flopped to the ground as her jaw swung open. "Wh-What?! I... I could never..."

Dusk raised a hoof, silencing her. "Shh... All I'm saying is, it's entirely up to you." Twilight's magic around Starlight faded. "If you don't want to, then go ahead and continue your studies."

Starlight's horn continued to hum with magic, but she didn't cast anything. Finally, it sputtered out, and Starlight slowly got to her hooves, her ears down and her head low. "I... I guess, mmmmmaybe just one..."

Dusk Shine put his hoof underneath Starlight's chin, bringing her gaze to his eyes. "Just one."

The two closed in, and their lips connected for a brief moment.

Pulling apart, Starlight Glimmer quickly activated her magic, teleporting away.

Dusk Shine licked his lips; for how short it was, Starlight's kiss was surprisingly gentle.

Smiling, the Prince of Friendship looked back at the black stone that had changed him into who he'd always been, and rolled his eyes before trotting over to the table to begin filling out his self-report.

Author's Note

I have no idea what I'm writing anymore... I should probably stop before someone gets hurt, lol.

Next chapter is the last, and it will be an epilogue.

Also, while it may have played a part in this chapter, the romantic feelings between Dusk Shine and Starlight will not be pursued by this fic, so I'm not going to change the tags to include romance.