“Goodnight, everypony! Thank you for coming!”
While Rarity escorted her friends out of her house, Twilight stood back and played with the dress rack near the back. Rarity wanted to tell Twilight something important; it was probably about what she'd said earlier that week regarding Rarity's magical power. It wasn't often you were told you were one of the most powerful unicorns of all time. With any luck, Rarity would realize what a gift she'd been given and not squander it.
“Thirteen.”
“Sorry?” Twilight turned around.
"I went and consulted a thaumatic specialist regarding my magical potential. He said I'm the thirteenth strongest unicorn in history. So saying it was me, you, and Starswirl, in that order, was gilding the lily somewhat, my dear."
Twilight blushed. "I guess so. I was a bit caught up in the moment. Still, thirteen is nothing to sneeze at. There are how many unicorns in Equestria? Thirteenth has to be at least three sigma."
"Something like that." She paused, fiddling with one of the dresses next to her. "It's a funny thing, you know. When you were young, Twilight, you knew for sure you would be magically talented, even when you weren't. It was all part of your self-image. But I? My magic was always just a tool to be used as part of my real passion. But this is so... important, isn't it? The things I could do with magic this powerful..."
"I never wanted you to abandon your goals, Rarity," Twilight said. "You're Rarity the dressmaker, and you shouldn't change that. But if you go to Celestia's school as an adult applicant, you could hone your magic and learn how to use it--"
Rarity raised a hoof. "Twilight, no. Let me ask you this. How many hours per day were classes?"
"Eight, but the adults usually only do half that."
"And how many hours outside of class did you study?"
"Four or five, but that was just me being--"
"I know, dear, but if my power is in your range, I'll have to study that much as well. So to get to the same level as you, I would need to devote eight hours a day to it. I need to sleep, just like anypony, and interact with friends and clients, so where would dressmaking go? I have an entire franchise to manage, not to mention my own business here in Ponyville. You're asking me to pick up a second job, for a skill I don't particularly care about, just because I'm the thirteenth most powerful magic user of all time."
Twilight sighed. "I know, I know. But I just can't help but imagine what you could achieve with the proper study."
"To what end?" Rarity asked. "I will never be Starswirl, even if I'm close in potential. I will never be you. I'm already doing what I love, so what would be the point?"
"How do you know you won't get anything out of it if you don't try?"
Rarity paused. "Well, there is one thing. The magical specialist wasn't the only pony I discussed this with."
"Oh?" Twilight said. "Whom else did you discuss this with?"
"I..." Rarity blushed. "I sent a letter to Shiverstone. And he responded."
Twilight boggled at this. "You sent a letter to one of the most reclusive magical prodigies, and he sent one back? What is he, number 6?"
"Number 8, once you add Starlight Glimmer and that young prodigy colt from Tailahassee. And as it turns out, Shiverstone is quite the gentlecolt, given the motivation to talk to me."
"What did you do, woo him with a pretty picture of yourself?" Twilight paused, noticed Rarity's blush, and facehoofed. "That's exactly what you did, isn't it."
"Before you get any ideas!" Rarity sputtered. "I'll have you know we've firmly established a strictly platonic relationship in our letters. Solely regarding my magical tutelage, nothing more."
"Your magical tutelage? What is he teaching you?"
Rarity pulled out one of the crystal projectors they'd discussed last time. "I never realized other fashion designers needed these to do what I could do without thinking. I figure, if I can learn how to make these, I could sell them on the side, make a little bit of profit off of that. And if my special talent really is crystals, then maybe I'll learn more about it from Shiverstone. I can find my own little niche in the field of magical study, as it were."
"I feel as though I need to apologize," said Twilight. "I know cutie marks can be interpreted in multiple different ways, and I never meant to suggest--"
"I understand, Twilight." Rarity walked away and stared out of the window. "You've heard my cutie mark story, yes, Twilight?" Twilight nodded. "Then you understand how I got the interpretation for my cutie mark I did. I saw an ugly rock, then discovered the beauty within it. That is my special talent. In fashion, that's taking a normal dress and making it spectacular. In friendship, it's bringing out the best in those I spend time with. And with magic... who knows? But if I can't use it to make the world more beautiful, I don't care."
Twilight smirked. "Like that time you got possessed by dark magic, right?"
"I swear, you get obsessed with turning the whole world into your own vision of perfection once, and you never live it down." Rarity laughed and shook her head. "But there is one thing I learned from that whole debacle. There isn't one type of beauty, and it doesn't always conform to my vision. Ponyville does not always need my intervention to become beautiful, when it already has its own wonderful charm."
"...Hmm."
"What's that, dear?"
"Oh! Nothing." Twilight sat up and brushed herself off. "I was just thinking about how... well, you don't need my intervention to become beautiful, when you have your own wonderful charm."
"Why, darling, I'm flattered you think I'm beautiful. I didn't know you thought of me that way." She magicked up a fan in front of herself and batted it in front of herself coquettishly.
This time, Twilight blushed. "Y-you know what I meant! You don't have to become my vision of 'a pony with powerful magic.' That's entirely your decision, and I respect that."
"Thank you, Twilight. I've figured it out my way, but I never would have known without your counsel. So, thank you, darling." She gave Twilight a fierce hug, and Twilight returned the gesture.
After a few seconds, Twilight whispered into Rarity's ear, "You know what we still have to do, though."
"What?" Rarity asked, leaving Twilight's embrace.
"A magic contest! Didn't you do any in your magic classes?" Twilight asked.
Rarity gave a gentle cough. "Ahem. I, er, didn't actually take any. When I opened up the boutique, I was still in school, and my teacher let me take half-classes so I could run the store. I'm entirely self-taught."
"No. That's..." Twilight put her face in her hooves. "Rarity, you're amazing, you know that, right?"
Rarity gave a wide smile. "My dear, of course I do. Now, you were saying something about a contest?"