"Don't you think you should wait for Starlight to come back from her trip?" Spike asked nervously.
Twilight laughed. "Don't be silly, Spike. I've been doing magical research for years with just your help. I don't need another unicorn to spot me."
"Yeah, but..." His eyes flickered over the stack of books, the materials, the preparations. "You yourself said this is a completely new spell. Nopony's ever done this before."
"That might not be true. The whole reason I got the idea was those books from the Crystal Empire I've been reading." She lifted one in her magic, taking a few merrily prancing steps toward it to meet it halfway. "Look, here, this is the first hint I've found in any record as to where Starswirl went, and it strongly implies he opened a dimensional portal. 'Then to defeat the evil did Starswirl banish himself and the Pillars to a world of darkness.' How do you banish yourself to another world without opening a portal?" She put the book down. "Discord insists that he's the one who created the gateway to the world Sunset's in, and all Starswirl did was anchor it into the mirror and put in containment spells to keep it from opening up just any old time, and after I saw what Discord did at the Gala that one year, I believe him. But Starswirl himself must have figured out how to create portal spells himself, because Discord says he doesn't know anything about this banishment to darkness thing and he himself was in another dimension when it happened, so he couldn't have created the portal in this case."
"But you haven't found any evidence of an incomplete spell in the Starswirl Wing or in the Crystal Empire."
"Right, and that's why this is so exciting!" She reared back on her hind legs and kicked her forehooves a little, unable to contain herself. "This will be new magic! Completely new magic, not like fixing a spell somepony else started!"
"And that's why I think you should wait for Starlight! She has experience creating completely new spells."
Despite her best efforts, Twilight's mood soured slightly. "Yes, her cutie mark removal spell. That was groundbreaking. Plus, she fixed one of Starswirl's spells herself when she got the time spell working. Starlight's amazing. That's why I want to do this now."
"You want to do this without her because she's amazing."
"Yes!" Twilight paced. "Spike, I had all the advantages. I was Princess Celestia's student. I had the run of the library. My job was just to learn magic, for ten years. I was so good at magic I became an alicorn. And Starlight, who never went to Princess Celestia's school at all, who didn't have nearly the same access to books of spells and theory that I did, managed to both fix one of Starswirl's spells – which is the thing I did that made me an alicorn – and create completely new magic from scratch, which I've never done. Don't you see, Spike?" She stopped pacing and looked at him. "She's better than me! At the thing I'm supposed to be an expert on!"
"I thought you were supposed to be an expert on friendship," Spike said. "And anyway, Starlight is ten years older than you. She just had a lot more time to learn magic and practice it."
"Yes, I'm supposed to be the friendship expert, but who was it who reformed the entire Changeling race? Starlight!"
"Actually I kinda think it was Thorax..."
"Well, okay, but because of advice Starlight gave him!" Twilight sighed. "I'm not jealous of her, don't get me wrong. It's not good to be jealous of a friend."
"That didn't stop you during the whole thing with Discord and our friends after the book sortation..."
Twilight ignored that. "She solved a friendship problem between the Princesses. She's... maybe not perfect, but she's mastered this whole friendship thing and reforming ponies after just one year of me teaching her. It took me three years to get to the point of becoming the Princess of Friendship! Four, before I figured out that was what I was princess of!"
"Starlight's still not a princess, and have you considered that maybe she learned faster because she had a teacher, and you had to do all the research on your own with your friends' help? I mean, why are you looking at this as 'Starlight learned about friendship faster than I did' when you could look at it as 'I taught Starlight about friendship so well she could reform the Changelings in only one year of study, when she started out as a supervillain?'"
"I'm not sure Starlight ever qualified as a supervillain, that's kind of a comic book thing—"
"She destroyed the world seven times, I think it counts."
"Okay, okay, I know what you're trying to say and I understand. And I shouldn't be jealous of Starlight, and yes, she's older than me so she's had more time to learn magic, but..." Twilight sighed. "Magical research used to be what I was known for. It was what I wanted to do with my life. This whole princess thing? I never expected this. I wouldn't change it, but... I don't feel like I'm really me anymore. I never get to do what I love, the first thing I was good at."
"I thought the first thing you were good at was reading."
"You know what I mean." Twilight brightened up. "So that's why I'm going to open a portal to another dimension, without Starlight's help, and prove beyond a doubt that that's a thing harmonic magic can do!"
"Okay, but if you won't get Starlight's help... don't you think at least some unicorn should be here to spot you in case something goes wrong?"
"I don't think Rarity or Sweetie Belle would be much help. Or anypony else in Ponyville, really. And besides, I have a lot of experience with this!" She raised her forehoof and pawed at the air, making imaginary check marks on equally imaginary ticky boxes. "Firstly, I've opened dimensional portals before. I was in the Realm of Chaos at the time and it's a lot easier to do it there than it is to do it here, but I know how it feels. Secondly, I was right there at the Gala when I saw Discord open a portal, and... the thing about chaos magic is that it's raw magic. Discord's so much more powerful than any of us because he can just talk to magic and get it to do what he wants without using any of the energy in building a constraint structure. But once he gets it to do a thing for him, I can see how the thing is built and figure out the constraint structure that would be needed to make it happen. Plus, thirdly, my counterpart in Sunset's universe opened a lot of dimensional portals without any trouble when she'd absorbed all the magic from my friends over there... which means she was probably about alicorn level at the time."
"I thought there was a lot less magic over there overall? Can anypony – sorry, anyone over there get to alicorn level?"
"Well, if she wasn't alicorn level then it's even more obvious that I should have enough raw power to do this!" Twilight gestured at the place where she was going to bring a portal into existence.
Spike sighed. "All right, fine..."
Twilight took a deep breath. It had long been held by the greatest minds in Equestria that it wasn't possible for harmonic magic, the type that unicorns and alicorns cast, to open dimensional portals, and that Starswirl had taken advantage of naturally occurring ones. Except Discord had confirmed that that wasn't true. A naturally occurring portal would have still been around for Discord to find if Starswirl had used it to banish himself, or the evil, or whatever it was that that passage was actually claiming he did. In fact, it had turned out the main reason Princess Celestia had wanted Discord reformed was his power to find and close the portals. Starswirl's had to be closed or Discord would have found it by now, and if Starswirl could close a portal, odds were he had opened it in the first place.
So Twilight's theory was that yes, harmonic magic could open portals, and that she could devise a spell that would do so.
She was about to make history. Well, okay, she'd made history several times by now, but she was about to do it again. Twilight checked her saddlebags once again, making sure that everything she'd planned to pack was still in them. Once the portal was opened, after all, she definitely wanted to go through it and explore the world on the other side, as long as it was safe for equine life over there.
She concentrated, shaped the spell in her mind, and fired it from her horn.
A distortion wavered in the air in front of her. Success! It wasn't something she could clearly see through, like the portal Discord had opened at the Gala or the one bound in the mirror, but it was definitely there. "YES!" she shouted, excited. She started to trot over to the distortion to stick her head in and see what it looked like on the other side, but common sense prevailed – once the horn that created the portal went through it, it might just close and spit her entire body out on the other side. "Spike, can you stick your head through and see what it looks like on the other side?"
"Sure." Spike walked toward the portal. "Uh, Twilight?"
"Is something wrong?"
"It feels like... something's pulling..." Spike tried to step back – and fell on his tail instead, whereupon he slid forward toward the portal. "It's pulling me in!"
"No!" Twilight grabbed onto him with her magic. The portal was definitely yanking at him. And at her magic. Her grip on Spike was weakening. It felt as if her magic was draining away from where it contacted him, toward the portal.
She charged forward and grabbed Spike's tail with her hooves, trying to use the earth pony strength of an alicorn to pull him back, but she had no traction – the crystal floor was smooth and polished, nothing to stop either of them from sliding forward. She tried using her wings, but it was too late. With a pair of screams, they both slid the last little bit across the floor and through the hole into another world.
From his home in Chaosville, Discord couldn't necessarily detect all the ebbs and flows of magic in Equestria, but something as significant as a dimensional portal made him sit up and take notice.
He'd been playing a card game with himself in which he changed the rules constantly. The other Discord adapted to the rule changes instantly, of course. It was a semi-detached alternate, like Specs but with less personality, so that he wouldn't immediately know its cards. But it wasn't very smart or good at this game, so it wasn't much of a challenge... or, honestly, much fun. This promised to be much more interesting.
The other Discord and the cards popped out of existence, and Discord himself appeared... right outside Twilight's castle. Oh, now, he should have guessed. If a random dimensional portal opened in Equestria, it would probably be either Twilight Sparkle or Starlight Glimmer's fault, and they both lived here. He couldn't teleport into the castle because of the harmonics, but he could certainly locate the portal. Quickly he flew there, already thinking of the funny things he'd say to Twilight or Starlight, whichever one of them was muscling in on his territory.
Except there was nopony there. Just an unstable portal, floating in midair. An unstable portal that was exerting enormous negative magical pressure on the room, attempting to suck in anything that contained enough magic to be pulled by the pressure. Discord was used to this kind of behavior, and had already magically anchored himself far enough away that the pull scarcely bothered him.
He saw skid marks from hooves and dragon claws on the floor, but no magical pony and no Spike.
A quick summoning brought him a scrying crystal that had been hardened against the harmonics. It found Starlight, in the Crystal Empire, spending quality time with her coltfriend. It did not find Twilight. It would have found her anywhere in the world, which meant she wasn't in the world.
Several thoughts and emotions ran through Discord all at once. Fear for Twilight and Spike, who were his friends. Deep irritation, bordering on anger, that Twilight had been such an idiot as to try to use harmonic magic to create a portal – that wasn't what harmonic magic was good at! You wanted a portal, use chaos! Excitement at the thought of being able to rescue Twilight, rub her nose in the fact that he'd saved her, and get praise for being a hero. Unease at the fact that he could see the branes in the portal separating, growing further apart slowly. Already, the return portal would have separated from the entrance portal, so Twilight wouldn't be able to just turn around and come back. She'd have to be told to find the return portal, that it would be separated... but if he waited too long, it could splinter again, and then the closest exit portal wouldn't be a return portal anymore and Twilight and Spike could end up having to play scavenger hunt to find their way back to Equestria at all.
He could tell from the characteristics of the portal that it opened to a place with gravity similar to Equestria's, with breathable air, where the laws of physics were roughly similar to Equestria's, but where there was very, very low magic. He could even tell that the world the portal opened onto was one he'd either been to before, or its close cognate – one of the myriad worlds of humans that populated the multiverse, not the pony-like humans from the world Twilight had visited but real, fully alien humans. There was no translation matrix, so they'd be over there as a pony and a dragon... in a world where there was one dominant tool-using sapient species, and they thought of all the other species as non-sapients.
Having been mistaken for a non-sapient being in his lifetime and having suffered greatly as a result, Discord didn't handle that thought well.
A low-magic world would drain him badly and he might not have the strength to get them back directly, without using Twilight's broken portal, but he should be able to replenish quickly enough from the ambient chaos in the environment that he'd at least be able to teleport to the exit portal. He'd have to end up in a place where there was no chaos he could reach at all – deep inside a cave system or in a frozen polar wasteland or something – for it to drain him so quickly that he wouldn't be able to help them. And the thought of leaving them there – of facing Fluttershy and telling her that Twilight was gone, that all they could do was wait for her to find her way back, of leaving brilliant Twilight and snarky little Spike in a world where the denizens would think they were animals, and where animals were routinely hunted for food... no.
All of this passed through his mind in a second. Without hesitating any further, he threw himself at the portal, planning to retrieve Twilight and Spike and bring them back home.
OH MY GOD im hyped! Ice was the first fic of yours I read and I am SO GLAD it's finally getting a multi-chapter series! This is going to be amazing
Horray! I'm eager to see the expansion of Ice!
I did not expect this would be how Discord and Twilight and Spike ended up on the other side of a portal together. Looking forward to more surprises!
And so it begins.
I was half-hoping that Discord would poof a note into existence about what happened before diving in.
9299013
Discord? Do something sensible? Naah.
Spike definitely has a healthy outlook on this. If Starlight friended further, it is because she stood on the withers of giants.
In any case, we have our scenario. Now to see how long it takes for the locals to realize this is a first contact event... and how deep the trouble gets before then, if the time ever arrives. Looking forward to finding out.
9299058
The show paints a different picture, one where Starlight is entirely self-made.
I gasped for a solid minute when I saw this!!!
This literally made my day.
I'm stoked you're writing this! I loved Ice
Words can not describe how happy I was when I saw that you made a sequel for Ice.
Aaah, this should be interesting! I eagerly look forward to Twilight's experiences with a new world and humanity's -- or humans', if not the whole -- reaction to learning that magic and unicorns and dragons are things that exist. Once the unfortunate incidents with Antarctica and the ocean are dealt with, anyway.
I dunno, you sure sound like you're jealous.
derpicdn.net/img/view/2017/4/1/1401156.gif
Ice was lovely.
I like how this Twilight realizes what a Mary Sue Starlight is in the show.
9299819
Starlight is not a Mary Sue. She's a reformed villain. There's a difference. Villains are usually stronger than the heroes; they have to be, to be a threat. Starlight is the first ordinary pony (as opposed to Changeling Queen, centaur, alicorn, draconequus or evil king) to serve as the main villain of a season, so she had to be an unusually talented ordinary pony to be a threat to Twilight and her friends. Many stories end up nerfing the reformed villain to get them to fit within the powerset of the heroes and not overshadow them -- this has happened to Magneto, like, umpteen zillion times, and fanfic writers keep doing it to Discord, so I'm actually happy they didn't nerf Starlight. She remains OP, as is proper for a character who was the villain of a season opener and a season ender. Only Discord and Chrysalis have done that besides her (and Discord, it was actually two different seasons, and the main big bad of the season finale he was a villain in was Tirek.)
My explanation for this is simple: Starlight is ten years older than Twilight, so much, much more of her knowledge is practical and experienced, rather than Twilight who's learned everything from books. Starlight's probably been studying magic as long as Twilight has, without the advantage of a mentor, but also without the effect of being boxed in that studying in a school gets you as opposed to self-study. She's invented more magic because she didn't have access to as many spellbooks, so she needed to learn to invent magic to get what she wants. It's why she was able to tie against Twilight despite Twilight being an alicorn -- Twilight has a lot more raw power, but Starlight has a lot more experience in using hers.
But yeah, Twilight is wigging out because she doesn't really understand the advantage age gives, and as far as she's seen, Starlight can do anything she can do. (This is not true, of course.) Not that Twilight's incapable of getting it into her head to test a new magic spell without backup before she ever met Starlight; the plot point where Twilight did this and got them all stuck on Earth was a thing I came up with in early 2014, after all. But I thought it'd add something to the story if I explicitly set it after Starlight and showed Twilight refusing to take advantage of the fact that she could have a unicorn mage spotting her because she's neurotic about Starlight.
Can't be out Earth. There's plenty of magic here.
(a wizardish-looking fellow leans into frame and scowls at Alondro)
Oh... OHH!! Yeah, right! Uhm, did I say plenty of magic? I meant NO MAGIC WHATSOEVER!! Not an iota! Eh-heh...
What the masses think of this fic.
9299870
I understand what you're saying, but I don't feel like saying Starlight is ten years older than Twilight is enough to account for what a complete upset her power level is. Twilight is literally The Chosen One in the show; from an early age she has the attention of Cadance, she has the Element of Magic on her cutie mark, she has a 6-way group destiny cutie mark, personal tutelage by Celestia and (implied) the finest tutors/instructors possible, she literally is part of and fulfills an ancient prophecy, "The stars shall aid in her escape", her cutie mark is on the Tree of Harmony right next to the other alicorns', etc. etc.
Starlight is a pony whose friend moved away to magic school which implies she didn't go to magic school or they wouldn't have been separated by more than a few weeks to months. Even though she says in season 5, "I spent years studying that spell!", why? Why would she spend years studying an attack spell? If her motivation was to eventually remove cutie marks and force equality so others wouldn't know her pain and loss, why would she spend years studying unrelated magic? And even then, what accounts for a random unicorn who couldn't even go to magic school being able to punch in the weight class of Immortal Alicorn Princess Sparkle, Chosen Pony of Destiny, Prophecy, and literal Legend? Or being able to cast harmful magics on two(!) other alicorns at the same time, switching their cutie marks like it was nothing?
Starlight is a "reformed" villain who keeps getting away with the same crap and harming her friends and rulers, and there's no justification for how she is so much stronger than everyone else. Being ten years older than Twilight is certainly not older than Celestia and Luna, and yet she can cast harmful magics on them with impunity as well. I get what you're saying, but Starlight in the show is most definitely riding Mary Sue powers.
9300869
Pretty sure it's just you buddy. The masses are digging the heck out of this
9300869
You have so little taste that not only do you not get why people like this, but you can't even say you dislike it in your own words.
A new low, ladies and gentlemen.
9300994
I got to deal with the likes of you?
9301192
You are truly a poet.
9299870
Isn't it?
9301531
Starlight can't wield the Elements of Harmony. She can't rapidly regenerate an injury, use pegasus or earth pony magic, or project magic through a different body part if her horn is restrained (this is an ability alicorns have in my stories; it's not canon but neither are horn restraints in the first place.) She has a lot fewer friends, most of whom she has through Twilight. My Twilight can analyze magic she's exposed to, and generally speaking can figure out how to replicate it; my version of Starlight either can't do that or can't do it as well. There are other differences as well, but I feel like I need to finish watching all the Starlight episodes before I can finish codifying my take on the character completely.
9301572
Neither is being able to rapidly regenerate an injury. In any case, "be an alicorn" (which this and the ability to use an iota of earth pony and pegasus magic amount to) is hardly impressive. Nothing about "being" is.
9301623
Not saying it's impressive. I'm simply saying Starlight can't do everything Twilight can do -- at least, based on my headcanon regarding alicorns and Twilight specifically, and nothing in the show has contradicted it.
9301572
Depending on what exactly is meant by "horn restraints", they are since the 2017 movie.
derpicdn.net/img/view/2018/1/25/1640458__safe_screencap_lyra+heartstrings_my+little+pony-colon-+the+movie_spoiler-colon-my+little+pony+movie_background+pony_bound+together_canterlot_c.jpeg
(Spoilers if you haven't seen it, naturally.)
9301652
Well, usually when people make that comparison, they're talking about worthwhile actions a person can take, and not something on the order of "have this exact shade of hair."
WOOOOOOOOOO!!
Edit: Oh, okay, this is more like you restarting that series of short stories with an effective Prelude. That works too...
9299076
In magic? Sure. In friendship? Do you remember how she came to reside in Twilight's castle?
9303475
Reasoned examination of the consequences of her actions and an internally-motivated request for aid and absolution?
I also remember A Royal Problem, where the Map gave Twilight a pointed reminder of where, how, and with whom Starlight surpassed her in friendship - and that, because she was not sent at all, she could not even grow to match, but was forever doomed to be stuck in her rut.
I also remember Starlight being able to connect with Maud where Twilight could not, and with Trixie and Discord where she would not.
9303499
I get that you're an apologist, but if you think Twilight wasn't the driving force in prompting Starlight to realize the error of her ways then you're pretending that Starlight did it all by herself, which frankly seems ludicrous though you're free to present your case.
Meanwhile, though, your second and third paragraphs forget the premise you're arguing against.
9303663
Starlight was the active person shaping events throughout The Cutie Re-Mark. Why should this matter be different?
You made a claim that Starlight was instructed in the ways of friendship (presumably by Twilight, though this is not stated), and was not self-made. I argued against that by pointing out examples of her singular accomplishments in the field of friendship.
9303683
Do you know what this was a reference to? Either way, do you know what it means? I ask because what you've been posting does not betray such knowledge.
9303711
It's a bullshit humblebrag by Isaac Newton. And being that it is such, I have chosen not to dignify it with any authoritative weight.
9303714
It's an observation that no caveman, however smart, could have invented calculus. And, similarly, without a lot of work on the part of Twilight Sparkle, Starlight wouldn't have been making those breakthroughs in friendship.
9303729
Work like what, exactly? All we see is bad advice and misguidance, a la "No Second Prances." Starlight learns in despite of her teacher, by her own effort, not because of her.
9303745
Yes, she reformed from being a supervillain all by herself. Clearly that would have happened with no input from the rest of the cast.
As for more current events, Twilight's far from perfect, but so's Starlight, unless you've forgotten that her first problem-solving impulses are magic, more magic, and mind control magic.
9303772
Well. I'm glad you've seen reason. Entirely under your own power and without external prompting. A Starlight-worthy achievement.
There is nothing necessarily wrong with using magic to solve problems.
9303780
OK, so you've been trolling this whole time. You got me, I guess.
Oh, an exciting start. That was quite a good opening, where Twilight does something incredibly stupid, but it is a very well-reasoned and character-consistent incredibly stupid.
9299870
Another factor is how much time has Twilight actually spent studying magic since becoming a princess. Between doing stuff for Celestia, outings with her friends and later friendship missions, we really haven't seen Twilight studying magic after season 3. Meanwhile Starlight was probably frantically experimenting in her cabin whenever she wasn't outside leading the villagers of Our Town in song. Then in Season 5 she was probably hiding out in libraries working on magic whenever she wasn't spying on Twilight.
There are some who believe Starlight may have also had another mentor as well, like a pen-pal relationship with Tirek or something.
I don't think Starlight is a Mary Sue because she's so poorly optimized for MLP. In RPG terms, Starlight is a blaster wizard where 95% of all problems are solved with Diplomacy Checks and Sense Motive, both of which she is pretty terrible at.
And of course Discord doesn't alert anyone or need a note. Discord having common sense or seriously entertaining the possibility of failure would be like Trixie speaking in the First Person.
9299058
That's a great line!
Oooh this is interesting. I really liked ice and the other chapter on desserts first, so it’s nice to see how it all happened.
I really liked Discord reasoning for going in alone so fast. Not the smartest thing to do since the least he could’ve done was leave a note explaining the situation, but it does feel like something Discord would do?
I enjoyed this chapter and I’m eager to see where this goes!
Can't wait to see more!
Another sequel to Ice? Hell, I'll take it. I'm curious to see where this'll go once we're caught up to Ocean.
9300939
Sorry for digging up a comment chain from half a year ago, but I had to say, I kind of agree with your point here. Starlight's power level is... strange. Alara's explanation for her version of Starlight, I can accept for story-telling purposes, but you do bring up a good point that Twilight has numerous advantages that Starlight simply doesn't, so there is a discrepancy still. As you say, Twilight was born powerful, chosen by destiny, and raised and taught by one of the most powerful beings on the planet. She has nature and nurture going for her. Starlight? I wouldn't think a similarly studious nature and ten year head start would bring her up to that level.
A friend of mine who also really likes overanalysing canon actually did a blog post on this exact subject once, positing the theory Starlight may possibly have had some kind of unseen mentor, for this and other reasons. Though personally, my favourite explanation for Starlight's power level is one that Shrink Laureate came up with in the comments of that blog, that Starlight's cutie mark removal spell/talent also allows her to copy spells from other ponies. Obviously, she'd still have to be pretty studious, considering all the new magic she's invented, but if she could copy spells directly like that without having to learn them the slow way, it'd go a long way towards explaining how she caught up with Twilight despite all her advantages.
9554525
Being able to copy spells wouldn't give her the power needed to cast them, though. She can go Blue Mage all she wants, but some spells just require more power under the hood; Twilight swapping cutie marks and fixing it was her literal ascension to alicornhood and required all of her friends and the EoH, while Starlight just does it impulsively by herself against the two legit-celestial alicorns (without having seen the cutie mark swap spell to copy it, I realized after some reflection).
Whether she has that copy ability or not, she still has far too much raw power for a random pony hiding at the ass-end of Equestria, not even using magic on a daily basis because none of her town's residents could and she needed and wanted to appear "equal" to fit in.
9555031
Well, I think swapping cutie marks around is more a feat of magical knowledge than one of raw power. Remember, back in season one, Apple Bloom asked Twilight to give her a cutie mark with magic, and Twilight was sceptical that such a thing was even possible. She tried anyway, but she couldn't do it. Then by the end of season three, she could, not because she was notably more powerful than in season one, but because she was more knowledgeable.
Starlight had that knowledge too because she spent years studying and creating her cutie unmarking spell, and I think it might be related to her special talent as well. Swapping cutie marks is just a natural extension of what Starlight was already doing from her first appearance. And if she could remove Twilight's cutie mark by taking her by surprise, then there's no special reason why that shouldn't work on the Royal Sisters as well. Though, why they let her get away with this instead of immediately throwing her in the dungeon is another question.
All that said, while I contend that knowledge is more important than raw power, Starlight definitely does have a lot of power as well. I think a better demonstration of what you're talking about with some spells requiring more magic would be when she banished Discord in Matter of Principals. Because whatever other effect it had, Starlight obviously put a lot of power behind it.
vignette.wikia.nocookie.net/mlp/images/4/40/Starlight_blasting_Discord_with_magic_S8E15.png/revision/latest?cb=20180806035222
vignette.wikia.nocookie.net/mlp/images/9/99/Starlight_leaves_a_crater_in_the_buckball_field_S8E15.png/revision/latest?cb=20180806035356
This is admittedly harder to account for, though if Starlight is already leaching knowledge from those she steals cutie marks from, I don't think it's a stretch to imagine that she leaches magic as well, Tirek-style (or at least that she used to when she was a villain). After all, there were a lot more cutie marks in that cave of hers than there were villagers in Ourtown, so she'd obviously been using her spell on ponies for years before. If she took even just a little bit of magic from every one of her victims, she probably would have built up quite the reserve by the time Twilight met her. And she probably went hunting for more while planning her revenge, too.
9556090
I think the important thing to recognize is that Twilight's first experience with her own magic was to turn her parents into potted plants and turn an egg into a giant dragon. Twilight's entire magic learning career has been about learning control and focus.
Starlight probably has as much raw magical power as Twilight the unicorn did, and a lot less motivation to restrain herself in any way. Her first experience with magic was, likely, feeling like she wasn't good enough or strong enough, because she wasn't talented enough to go to Celestia's school with Sunburst. I feel as if for Starlight, the struggle to achieve raw power came first, the control second; she's extremely adept with her control, but she has no psychological barriers against letting loose completely when she has to. Twilight does.
This actually makes Twilight a better candidate for Element of Magic and eventual successor to Celestia than Starlight, who is a neurotic mess who brainwashes ponies so she can have some friends, but it does mean Starlight has a lot of raw power. Not more than Twilight, but more than Twilight would usually allow herself to use.
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A general lack of restraint has certainly been a defining quality of Starlight, both as a villain and a hero. It's one of her most persistent recurring character flaws. Even after her reformation arc, she still often acts impulsively and without stopping to think of the consequences of her actions. It's only natural that such a flaw would be reflected in her approach to magic as well.
That said, how does a unicorn build up their power in your magic system? Obviously magical beings have an internal supply of magic, since Tirek was able to steal it from them and all, but from your other stories, magic in the Last Draconequus universe seems to mostly be found in and drawn from the local environment. Even Discord is severely weakened by low-magic environments like Earth or the Frozen North. So if a unicorn like Starlight has a limited reserve of power, and they replenish it when low by drawing from the environment, then how does building up more raw power work? Can any unicorn just keep drawing magic from their surroundings without limit until they're a powerhouse like Twilight and Starlight? Or do they have a personal limit on how much they can gather that they have to increase by exercising?
My personal theory for why Starlight is so strong is that she's the magical equivalent of the Hulk: the stronger her emotions the stronger her magic gets, which is actually different than most unicorns. It led to her sort of spoiling herself since any stress would solve itself by giving her the strength to get rid of the stressor, and anything magic couldn't fix (such as Sunburst leaving, losing her town) just led to her strength going up until it let her do something that made her feel better.