Spike let out a belch and flopped to the ground in an ungainly display. Twilight caught the resulting scroll in her magic. "From the princess?" She had it open quickly, eyes sweeping back and forth. "I am overjoyed to hear that Sombra has been put to rest and the Crystal Empire restored. However, your report of 'Queen Umbra' does cause some amount of concern. If you could keep an eye on her and give a more detailed report, I would appreciate it."
Umbra leaned in and to the right over Twilight's shoulder. "Should I not have heard that?"
Spike laughed even as he sat up. "Probably not."
Twilight colored at her error. "That just means I don't have to keep it a secret. Besides, I was studying you anyway, so this changes nothing." She nodded with rebounding confidence. "Now..." She resumed reading, "A wielder of shadow magic can be very dangerous. If they have a dark temperament, pardon the pun, they can not only manipulate light and shadow and crystals, but also the shadow of a pony's mind. Dream manipulation, thought control, and other potentially hazardous things could result. Sombra was feared because he wielded his populace as a weapon that obeyed him without a choice in the matter."
Umbra squirmed as the list of potential problems were raised. "I'm not like that!" she assured, even if her voice conflicted with her nervousness, a dark mistress that didn't want to be judged harshly. "But... I can do that?"
"I would like to find out." Twilight nodded. "But only if they are used by a good pony." She reached out, placing a hoof on Umbra's chest. "Which, so far, you have shown yourself to be. Any magic is a tool, not evil or good until used in an evil or good way."
"Yeah!" Spike had regained his footing. "You're pretty nice. You remind me of a worryingly powerful wizard Fluttershy really." He rubbed behind his head. "I mean that in a good way."
Twilight raised a hoof to her chin. "You're no wizard just yet. You're only using your magic instinctively, not with practice or knowledge. Do you want to change that?"
"Yes. Si. Oui! Hai?" Umbra was bobbing her head furiously as she ran through all the yesses she could think of. "That sounds super fun. I'll be responsible, promise. But, really, shadow in people's heads?" She tapped at her own head. "Sure it's kinda dark in there?"
"These are the powers." Twilight tapped at the floating scroll. "At least the ones that Sombra knew and displayed. You are... like him. You've shown you have a similar kind of magic. You even wore his armor when you first appeared. If we imagined a female Sombra, that's you." She shrugged softly at that. "Though far nicer."
Umbra clopped with giddy enthusiasm. "Well, I'm not a jerk, so show me how I can do good things with it." She leaned forward suddenly. "She said dreams, right? Can I help someone get good sleep? Can I help myself get good sleep? That's a super power I will take!"
Spike patted Umbra on the side. "You sound eager to start."
"Because I am!" Umbra turned on Spike in a sharp spin, lifting off all but one hoof to spin in place a moment. "Before... all this, I was just a... person with no magic and barely any hope for the future. Now I'm a super mare! What's not to be excited about?" She began to dance in place. "I want to be a good pony."
Pinkie popped out from behind a column. "Ya know, it never stops being odd hearing that voice being that happy, but I like it!" She pronked towards Umbra with a joyful grin. "By the way, the party's on for tomorrow."
"Tomorrow?!" Umbra's joy deflated. "That soon?"
Pinkie inclined her head. "Why the frown? It'll just be us." She waved a hoof in a circle. "The girls, Cadance, and Shiny! Oh, and you, duh." Her tail casually poked her in the side. When she glanced at it, it pointed at Spike. "Oh, right! And Spike! You two are buddies now, right?"
Umbra threw an arm around Spike. "Yes."
Spike colored at the sudden embrace. "I'd better get a gift." He tried to squirm away, but Umbra held him.
"Spike, you being there is a gift. Seriously, I'm drowning in blessings right now." She released him then if only to throw her hooves wide. "I'm a magic pretty pony!" Her nervousness forgotten, she resumed dancing in place. "Twilight, teach me. I am ready to learn!"
Pinkie clapped with approval. "That's great. Good to hear you're happy about things. Some ponies are gonna be super nervous with you flinging shadow magic around, but you'll handle it great!"
That vote of encouragement did little to help keep Umbra's mood high. "Oh..." She sank back to her haunches. "I'm gonna look creepy whenever I do it, aren't I?"
"Probably," admitted Twilight with a shrug. "That seems to be part of the package. Still, if you gain a reputation for being a good pony..."
"Then... they'll get past it, eventually," hoped Umbra out loud, not sounding entirely sure. "At least the ponies right here are alright with it."
"Totally fine." Pinkie threw an arm over Umbra, squeezing. "Now, there are last touches to do. See you tomorrow!" And she vanished in a puff of pink smoke off to do her party-related magic.
Umbra rubbed a cheek with the flat of a hoof. "On one... hoof... I'd almost want party magic, on the other, look what it's done to Pinkie."
Spike smirked at the proposed theory. "Poor Pinkie, if only she hadn't gotten into that foul party magic." He made a few lucky symbols of a gesture, chuckling. "You'll do better with yours."
"With my help," announced Twilight proudly. "Speaking of that, let's stick to the basics, which you have not mastered. For instance, you can make yourself into a shadow, but you haven't exerted any control over shadows that aren't you, so far."
Umbra raised a brow. "Well... I am shadow." She rose and shook herself out. "Umbra, shadow. I just... have to read in there." She trembled as she concentrated, wafts of shadow magic leaking from her eyes without much other visible effect. "Just..."
Twilight inclined her head. "You need to learn how to use one of these, I think." She pointed up at her horn. "You have good instinctual use of it. You can light it and grab things, but no finesse past that. A fine start, but just a start."
Spike bobbed his head. "Twilight had her horn working when she got into magic school, and she had way more to learn." He turned to Twilight. "Going to take her to Magic Kindergarten?"
Twilight shuddered. "I wouldn't be so cruel. But there is a lot to go over. Do you want to start now, or after your party?"
Umbra leaned in, tapping her horn to Twilight's. "Pretty sure I answered that, nerd horse."
"Nerd horse?!" Twilight looked appropriately affronted. "I expect that sort of nonsense from Rainbow Dash."
Umbra went red. "Sorry! I didn't mean to offend."
Twilight looked confused at the whiplash. "I'm not that offended... Um, either way, as your teacher, you should address me with respect." She nodded with rebounding confidence. She knew how teacher student relationships were supposed to be. "Under my tutelage, we'll advance your understandings, but you have to listen and do as I say, even the parts that aren't very fun."
Spike hiked a thumb at his nerd of a big sister. "She's gonna channel Celestia now."
"Spike!" Twilight's cheeks puffed in defiance. "I am not... I've had other teachers besides her." She turned up her nose and refocused on Umbra, only to blink. "You alright?"
Umbra was fidgeting nervously. "School was not my favorite place, but this isn't school. This... You're a friend, I get that. You're a friend just showing me how to do something. Not school at all." She laughed tensely, trying to convince herself. "No desks, no blackboards."
Twilight mentally threw out the desk and blackboard she had planned. "No, none of that," she promised with a smile, her original plan dashed. "Just two ponies talking about how to do magic. But I do need you to listen and follow my directions. Is that alright?"
"Yes!" For whatever nervousness Umbra had a moment before, it was thrown aside. "Show me. School, not my fave, but just shutting up and listening to someone I trust, that's different." She sat on her haunches to clop her forehooves. "Learn me some magic!"
"You have to do the learning," corrected Twilight officiously. "I will do the teaching. Now, let's start with some basic horn principles. That thing isn't there for decoration." She pointed at her own horn, less spectacular than the gradient-wielding model that Umbra had. "Let us begin."
Shining looked across the table at his wife. They were in a small room, almost cramped. There were no guards, just the two of them, granted privacy. "Twily's off in her own world."
"As usual." Cadance nodded gently. "But I don't entirely disagree with her."
"You don't?" He quirked an ear at her. "We're dealing with a wielder of potentially horrific magic."
"We're dealing with a vulnerable mare that desperately wants to fit in." Cadance reached across the table, setting her hoof on his shoulder. "Not a dark overlord."
"Now, this is just a theory." Shining set his hooves together. "But is it possible she attached herself to us on purpose? It makes attacking her basically impossible."
Cadance drew her hoof back. "For the sake of argument, alright. Let's say she did exactly that. I'd almost be relieved, since it would likely mean she could undo it as soon as we convinced her she was safe to do so. But let's not hop to that. She did it, she wove a spell of intense power that hooked all three of us to the Crystal Heart."
"And now she can monitor us." Shining tapped the table for emphasis. "And is using us as a shield."
Cadance raised a brow. "You volunteered for shield status, Shiny. 'I will protect these hearts', was it? I don't think she forced those words out of you."
Shining deflated in place. "Just... What if? We're arming what could be our own worst enemy. We're training them, giving them a nice place to live and grow in strength. We'll look pretty bad if she turns out to be Sombra 2.0, which she already looks like."
"Counter proposal." Cadance set her own hooves together at the center of her chest. "Let's say she is doing everything you said. She made the link, and she's hoping to gain an advantage over us for nefarious ends. This is our chance to head off a problem before it becomes a crisis. We can turn her away from such thoughts. By surrounding her with genuine care, she'll become increasingly less likely to want to hurt anything."
Shining quirked a little smile. "You do look for the better side." A pause. "Unless it's a changeling."
That got him a scowl. "Hardly a fair comparison. But there are no changelings." She huffed at the idea. "With any luck, there never will be a single one in the city."
"Hopefully not." It was his turn to offer her pats. "And now she's probably wondering what we're doing."
Cadance burst into a snicker. "We're married. Touching each other is part of the package. A little poke and pat is hardly on the radar. Now, really. Umbra is scared, not plotting mischief." Her eyes rolled softly. "On the other hoof, she is learning from Twilight. I will be honestly shocked if they don't cause some amount of mischief without trying. But that's Twily's fault, and we're not getting rid of her, hm?"
"No! 'Course not." He huffed and fidgeted at the idea of kicking his precious little sister to any metaphorical curb. "You're right. We have Twilight, right there, keeping an eye on her. She takes orders from Princess Celestia very seriously, so I imagine she's working extra hard to figure Umbra out."
Twilight gestured to a strange machine with a cap. "I learned a lot from my... prior mistakes. Besides, your magic is well documented." She clopped her hooves. "We're not proving something, we're measuring it, and it should be much easier all around. If you would put that on?"
Umbra held up the helmet in her magic, eyeing it as she turned it left and right as far as she could without tangling the many cords attached to it. "Are you doing a brain scan?"
Twilight's ears pricked. "Yes, actually. I'm impressed you figured that out just by looking at it."
Umbra poked lightly. "Looks like the kind of thing you'd measure impulses with." She stepped forward as she brought the helmet in, slipping it snugly over her head, ears poking through available holes. Her tiara was not on, having been warned it would get in the way. "Alright." She looked up at her horn as best she could, thrust up through a third hole. "Now what?"
"Now we get a baseline." Twilight's horn was glowing as she got the machine humming and glowing, papers spilling out onto the floor. "So just relax and don't think about anything that strongly."
Umbra burst into giggles. "Whatever you do, do not think of a pink elephant."
"Yes." She paused. "Oh." The pink pachyderm had clearly visited her. "Ha ha." She looked over the line being produced. "This looks good though. Now, go ahead and lift this." She floated over a small ball and set it in front of Umbra. "Just pick it up." When Umbra reached for it, Twilight thrust out a hoof. "With your magic."
"Oh." Umbra's horn began to glow, the ball lifting, wrapped in her shadowy magic as it began to hover in the air at her eye level. "Like that?"
"Perfect." A quill floated over, making marks on the charts where Umbra began to use her magic for later review. "Now put it down." When the ball was set down, Twilight went right on, "Let's try a spell."
"Skipping crystal sculpting?" Umbra wobbled a hoof over the ground, imagining the work but not actually messing with the crystal floor.
"For now. Go ahead, the one we went over." Twilight rolled a hoof to continue, watching intently.
It wasn't as if Umbra had a lot of spells to pick from, just the one that she had learned at Twilight's hooves. "Alright." She focused on the spell that came naturally to her, the very same that Twilight had to struggle to do. Sensible enough, considering its nature. She began emitting a line of pure shadow magic in a line to the floor. "Should I aim this anywhere?"
"Hold it steady." Twilight made new marks, a few question marks to join in other places. "Hm... Curious."
"That's a funny party hat." Pinkie had appeared, as was her wont. "Not sure it'll catch on."
"Pinkie!" Umbra looked at her, also blasting her with shadow magic for an instant, her squeak coming even as she ended the spell. "Are you alright?!"
Pinkie coughed, her face blackened with the blast. "Not the first time I got a kaboom in the face for coming in when Twilight was busy doing science." She did not seem bothered at all, pointing instead. "But you're gonna be late for your own party and that is not something I can tolerate, young lady!"
"Interesting." Twilight made a final note, her magic drawing the helmet free of Umbra. "Alright, Pinkie planned this before I did, so let's go have some fun."
Umbra brought over a rag floating in her magic, quickly trying to wipe Pinkie clean of the soot. "I'm so sorry. Does it hurt? You sure you're alright?"
Pinkie grabbed the rag with a hoof, wiping away the mess in one grand swipe that left her good as new. "Ta da! Now is party time." She bonked her head against Umbra's. "PS: I'm not mad. I'm the one that came in all of a sudden." She nodded firmly. "These are the prices a party pony must face, if they are to bring joy to the world!" She turned in place for the exit. "A price I will gladly pay! Now c'mon! It's hardly a party without the pony of honor."
So the science of magic was set aside in favor of festivities. The girls were there, as well as the royal couple. Decorations hung from the ceiling. Party favors were scattered almost haphazardly. Games were setup on the wall, on the floor, and even the ceiling in the form of a piñata swaying lightly with a bat nearby, waiting to be bashed open.
A table, longer than wide, but plenty of both, had a fine cloth draped over it. On that, a variety of snacks and drinks. Spike was sipping from a cup beside that, watching the party.
Applejack closed with Umbra as she arrived. "There ya are! Twilight not messin' wit' ya too badly, ah hope?"
Rarity floated a pastry over into Umbra's range, close to her snout. "Pish posh. Umbra is a very willing subject, from what I can gather, darling."
Umbra accepted the unspoken offer, taking a big chomp of the floating sweet. "Mmm! Nice. Thanks for coming, both of you." Soon she had an arm around either mare, hugging with a sharp smile. "Twilight's been great. I'm starting to learn how do be... me." She paused a moment, frowning. "Even if that may be a little scary? I'll use it for good! Not sure what that shadow beam's good for though."
Twilight took up position next to Umbra. "You can blame that on me. It was the only shadow spell I had on hoof, and I had a hunch you'd be able to pick it up quickly."
"You weren't wrong." Umbra had been able to pick up and gallop off with the spell in hardly any time. "Just wish it did something useful." She turned in place. "Say... If Sombra had this spell..." Her horn began to glow, eyes trailing with power as they colored a vibrant green. Shadow magic gathered in purples and greens. "Something might react." She turned in place, taking in the throne room, the nervous guards, the curious mares, the royal couple... She began zapping things largely at random, non-living things that didn't seem to care.
Twilight waved a hoof at the idea. "Even if there is something, the odds of finding it randomly are--" Umbra struck the right crystal, a large one behind the throne. Shadow spread out through the center of the room, sending ponies scurrying out of the way. It gave way to a hole, stairs leading downwards.
With a great crash, the table with the food slammed to the side, falling right off the ledge that had been created under one of its legs. The food on it began to slide quickly towards the hole. Spike threw himself in the way with a heroic battle cry, almost sliding in himself, but he managed to brake himself, barely clinging to the edge of the table.
Applejack got in on one side of the table, Rainbow Dash the other, the two working to heft the table upright and back onto solid ground. Rainbow was laughing at the whole thing. "Well! Guess that spell does something."
Twilight inclined her head at the new gaping tunnel created. "So it did..." She glanced at Pinkie. "Now... I want to see what's down there, but..."
Pinkie nodded with all due gravity. "Party paused on account of sudden mystery! We're restarting the moment we figure it out though." That settled, she got to hopping down the stairs. "Think of this like a party game. A shadow party game, ooo, that's a first for me."
Unlike some other timeline, the entire crew began down after her. Shining Armor advanced to the fore, horn glowing in preparation. "Umbra, you really shouldn't just play with shadow magic like that."
"Who knows what's down here." Cadance was just behind Shining. "It may be nothing, or something terrible. Hardly the way we want to end your party."
Umbra's expression was torn between the giddiness of having found something and the shame of causing trouble. "I'll be more careful," she promised, looking aside at Twilight. "You wanna see, right?"
"Very much yes," agreed Twilight without hesitation. "This is... a foreboding place. Glad we're all here." She smiled at all her gathered friends, her peers and older siblings all. "We can handle this, together."
"Yeah..." Spike stepped down carefully. "Glad we're not scouting this alone."
"End of the line." Shining had reached the bottom at long last, where a door sat forebodingly. "Not sure we should touch that."
"Dear." Cadance went around him onto the level plane before the door. "We came this far. To stop at the first hint of a challenge?"
"I volunteer." Umbra advanced towards the door without fear. "If there's some wacky shadow trap, well, I am that, so what'll it do? Oh no, my fur may go grey." She snorted at the idea. "Don't worry, I got this!" She reached for the doorknob, horn glowing as she took arcane grip of it.
She wasn't a pretty pony. She wasn't even a pony. She wasn't even a she, by some views. An angry view. "You need to snap out of it," bellowed an angry male voice. "This is why you can't get any god damned thing done," boomed the towering figure of wrath. "Stop it with the girly stuff. You aren't that. You never will be that. Face reality." She was struck across the face, sent in an uneven heap on the dirty carpet of a home she had lost so long ago.
"I'm sorry," she sniffled, getting back to her feet. "I'm not the little boy you wanted."
"Yes you are," angrily asserted the figure. "Even if I have to beat that bullshit out of your hea--"
Umbra was pulled back from the door, tears streaking her face, body shivering with emotions. "Oh... Oh god..."
Twilight let out a slow breath. "Just because you are a shadow creature doesn't mean shadow magic can't affect you. Are you alright?"
Cadance was the one drawing Umbra way from the cursed portal. "Your eyes began to glow, like you were doing magic, but you didn't seem to hear us, just whatever was in your head. It must have been awful."
"Awful... but true." Umbra frowned at the memory she tried to shove aside. "I'm alright... Really..." She shook herself vigorously, her tiara bouncing. "Did you get past the door?"
They had not. Twilight's eyes rose to the crystal at the top of the door. "If the crystal behind the throne reacted to the shadow spell, there's a good chance this one will as well. I can do it, if you're feeling bad."
"I am, but I'm doing it anyway." Her horn and eyes began to glow with the easily conjured shadow magic, perhaps all the fiercer for the dark emotions conjured within her. "Gonna zap that thing real good."
With an angry zap, they could proceed to the stairs that led upwards seemingly into the infinite. Cadance spread her wings. "Perhaps those of us with the option would be better off checking this out on our own?"
"I'm with ya!" Rainbow snapped out her wings and soon the two of them vanished straight upwards like two loosed arrows.
Spike peered at Fluttershy. "Not going?"
"Um... no." She edged closer to the center of the group. "I'm happy right here."
Applejack looped back to the door. "This can't be all that bad." She closed the door and made to re-open it, just to face her worst nightmares.
When Umbra drew her away, Applejack's tears were flowing just as thickly as Umbra's had. "It's alright."
"No, it ain't." Applejack buried her face into Umbra's neck. "Sorry ah thought you were bein' silly."