Hallowe'en Sonata

by Radiant Sparkle

Rating: everyone
Tags: Crossover, Sonata Dusk, Alternate Universe, Equestria Girls
Length: 3930

Sonata Dusk has a Hallowe'en she can neither explain nor forget!

Written for a group of friends on another site as a dare, I'm posting it here because ponies. And Sonata Dusk, which should be reason enough. :) It involves a Hallowe'en event where a random collection of anime characters from across the multiverse have apparently shown up at the same party. Unable to resist the urge to meddle, one of them decides to give Sonata a second chance. This story is what happens.

Published 2019-10-30 00:40:01 UTC
Last updated 2019-10-30 00:40:01 UTC

What was in that punch again?

The girl walked slowly across the outside lawn, and hesitated at the steps leading up. She looked around curiously, and blinked a few more times. The pulse-pounding beat inside drew her forward. Music called to her, the way it always had. Well... Until recently.

The girl brushed her two-tone hair out of an eye, and considered the landscape. Ten minutes ago she’s stormed away from her sisters. Adagio, as usual, was talking about going into town. The locals called it ‘Hallowe’en,’ instead of Nightmare Night, but it was basically the same thing. Adagio, being the sexed-up floozie she was when she wasn’t threatening Aria or yelling at her, decided to find some hot boy in a macho costume, and give him an education, or something like that. Whatever. Not her thing.

Which wasn’t to say sex wasn’t fun. Even Sonata had gotten lucky now and then. You couldn’t live for a thousand years plus without finding the occasional piece of hot property. But since last summer, it just hadn’t been as much fun. Not since...

Sonata inhaled sharply, banishing the memory for the umpteenth time even as she pushed back the tears. She pulled out the tiny box she carried, and opened it like she did pretty much every day since.

Inside, the shattered remains of the red crystal lay on a black velvet pad. Her crystal. Without it, she didn’t have her music anymore. Without it, she didn’t have her extended lifespan.

Without it, she couldn’t go home. Ever.

The scent of party food reached her as she brooded on the steps. Closing the box with a brittle smile, she pocketed the container and took a deeper breath. “Food,” she said finally, choosing to ignore the hitch in her voice as she said it. “I really need food.”

She pulled the door open and wandered inside. “I wonder if they have tacos?”

* * *

Fate drifted across the edge of the party, and smiled as she saw some boy try very skittishly to chat up Nanoha. He was roughly her age, with short cropped brown hair, and a sparse frame. He seemed to be a bit of a wallflower, but if she knew Nanoha, Fate had no doubt she’d pair him up with someone who would draw him out of his shell. She hadn’t become a legendary mage-ace and Striker commander by missing the obvious. She wondered who the boy would eventually be matched up with.

Another figure walked into the party that Fate didn’t recognize. To say she didn’t know anyone was an understatement. She wasn’t entirely sure how this party was even possible. Some of the people claimed to be from places and times that simply couldn’t exist in the same timeline.

Her Device pinged softly, drawing her out of her reverie. She blushed and held the crystal up to look at it. “Gomen, Bardiche. I was spacing out on the impossibility again.”

The machine chimed softly. “Distraction comes in many forms.”

“Hai.” She held the crystal to herself for a long moment before putting it away. Bardiche was right, as usual. She needed something to distract her from the improbability of the Hallowe’en party she was at and just enjoy it for a while.

Another glance across the other way showed Nanoha engaging the boy and another girl in a fairly animated conversation. Seeing the matter well in hand, Fate drifted around to the other arrival she’d seen. The girl was sneaking party food onto a plate, and looking around at everyone else. She bit her lip and selected something to drink before sliding to the patio door. Suppressing a grin, Fate followed along behind.

Sonata exited the party to the yard outside. Finding a nice spot just out of sight, she sat down, and hefted the first of several tacos she’d loaded up. She paused for a long second when she heard the quiet tapping sound behind her, of someone knocking on the tree to one side. Grinning unrepentantly, she looked back.

The girl was dressed in some kind of Nightmare Night costume Sonata didn’t recognize. She had long blonde hair, deep red eyes, and a smirk on her face. “Umm... Hello?”

Fate sat down beside Sonata, placing her own plate of snack foods in front of her. “Crashing the party, huh?”

The party crasher just made a sound and shrugged as she bit into the taco. “Mmmm! Oh, that’s soooo good!” She pointedly ignored Fate for the few moments it took to scarf the entire taco, then sat back with a contented sigh as she sipped her drink. “So. Gonna tell the others on me?”

Fate snorted. “Nah. What’s one more party guest, right?” She waved around at the house in the distance. “Besides, I barely know anyone here myself. My girlfriend and I were at a party elsewhere when we ran into this guy who invited us back here. So if they’re okay with us, I don’t see why they’d mind another party crasher.”

Sonata held up a second taco. “Works for me!” She bit in with clear enjoyment, much to Fate’s amusement. After a long moment of chewing and swallowing, she sipped her drink and tapped it to her forehead. “Sonata Dusk.”

“Fate Testarossa.” She pulled out a golden metal triangle inset with a golden gemstone, and placed it beside her. “And this is Bardiche.”

“Greetings,” the Device chimed.

Sonata blinked several times at the strange event, and bit her lip. “A talking magic stone? I’ve never seen something like that before.” She tilted her head to one side. “So is it really intelligent, or you know, reading from cue cards?”

Fate snickered as the light shifted across one of Bardiche’s facets. The device was really good at suggesting emotional reactions for a mystical machine that didn’t speak literally any more than it absolutely had to. “He’s alive. Just different from us.” She looked over at the other girl, and touched an arm. “So... what are you going as tonight, anyway? I’ve been able to guess some of the people here, but frankly, the light pastel skin tone is really confusing me.”

This elicited a giggle from the other girl. After a few more snickers, Sonata looked back at Fate. “I’m not going as anything right now. This is my normal skin tone.” She leaned over and stage-whispered to the other girl. “I’m a SIREN!”

“Ri-ight,” Fate drawled as Sonata finished off her second taco. “I suppose you’re going to break into song now?”

The sharp inhalation caught Fate entirely off guard. The blue skinned girl balled her hand into a tiny fist on the table and rocked slowly as she clearly tried to compose herself. “I can’t,” she replied quietly, voice scratchy. “My stone was destroyed last year.”

As Fate watched, a million questions in her head, the other girl took out what looked like an earring box, and opened it. Inside, the remains of an elaborately cut ruby gemstone lay. It was easy to see how the shards all fit together, but it just lay in the black box, a dull and lifeless reminder of what Sonata had lost. “Without my stone...”

Sonata touched the crystal with a gentle longing that sent a pang through Fate. It didn’t take much to see herself holding the destroyed remains of Bardiche that time many years ago when Signum had all but killed her. The almost-loss of her partner had devastated her. And she’d gotten him back. She could only imagine what it must feel like to lose something that important and know you would never get it back.

Fate made a decision in that moment. She didn’t know if it was a good decision or not, only that it was the only choice she could make that she could possibly live with. “I... might be able to help with that,” she said, very softly, as she placed her hand on Sonata’s arm. “If... you want me to.”

The blue-skinned girl’s look of deeply pained need was all the answer Fate needed. Gesturing to the side, she caused Bardiche’s storage pocket to open. “I’m a magical enforcement type back home. But when I’m not handling security issues, I also teach advanced tactics to magical adepts and student prodigies.” She paused as she reached in to pull the object of her focus out. “Wow. That just sounds really elitist when I say it like that.”

Sonata giggled, wiping away tears as she watched the other girl take out what looked like a magic rod of some kind. It had a kind of abbreviated weapons head on the top, split into two stubby prongs. The girl placed it on the table.

“This is a training weapon we use to teach basic magical control and some combat to academy trainees.” She touched the oval gemstone in the weapon’s head. “This is a generic device which is used to manage the energy flows and maintain the weapon. It’s like an entry-level version of what Bardiche is. Given time, it could be upgraded to include more power, and a personality of its own.”

“How does that help me with my stone?”

Fate touched the oval stone in a specific pattern, while focusing on a simple spell. With a faint click, the stone came free from the staff weapon. Holding it up, Fate looked over at the fragments. “I want to use magic to blend the two items together. Your stone will become part of this power core, which will also become part of your crystal. My goal is to see if I can restore the stone and give it an independent power core, as well as the ability to fix itself going forward, so that this doesn’t happen again.”

Sonata blinked several times, processing the possibilities. If it worked, she’d get her powers back. Adagio would be furious, of course. She might even try to take it away from her. Aria would pretend to not care, and try to steal it while Sonata slept. She’d have to do something about that.

As for the party nearby... Sonata glanced back at the people. Even without her crystal, she still had enough of her old power that she could sense it. Their need. Their energy. With the stone to push them, and to amplify her song, they’d gravitate to her like iron to a magnet. They’d fight over who got to spend more time with her. And she could soak up all that wonderful, delicious energy.

She caught herself up short when she became aware of something more. Even at her low strength, she could clearly sense a great many people in the party who had astounding power levels. It was like being within a stone’s throw of a whole dance party of Princess Celestias. And while the urge to take their energy was strong, she wasn’t suicidal.

She looked back at the expectant girl beside her. Get the stone back. Play nice at the party. Live long enough to get away with her restored power. “Umm,” she began slowly. “Okay. I mean, if it works... right?”

Fate nodded and grinned encouragingly. “Let’s see if we can pull this off.” waving the floating stone down to hover over the red fragments, she gathered her power and fed it to the utility weapon crystal. The stone began to glow, and reached tendrils of power out to the red fragments as the mystical machine within processed Fate’s intent and began to put the mage’s will into action.

Sonata watched as the oval stone’s glow seemed to seep down into the ruby fragments. Then, amazingly, they began to glow as well. Sonata could feel it. A faint pulse of their old, familiar energy, as the fragments were pulled up and *into* the oval, vanishing within.

With a flare of light, the oval vanished. In its place, the restored ruby stone floated, aglow with its own magical potential. Sonata reached out to it, eyes wide. Her expression was one of total disbelief and wonder, as she touched the surface of the stone. Even though her stone had never had a mind of its own, she couldn’t help the hopeful whisper. “Do you... remember me?”

In answer, the stone glowed more brilliantly, and flew across the space between to hover at neck level. A flare of energy heralded it somehow creating a pendant form for it to rest in, as the completed necklace lay against her throat.

Sonata closed her eyes and breathed deep, touching the stone and concentrating. She could feel it pulse in time with her heartbeat. The power inside was still nothing more than a fraction of the vast pools it could contain, but it was cool and incredibly welcome.

The girl opened her eyes and looked over at the expectant blonde girl. With a squeal, Sonata lunged across and tackle-hugged the other girl. “That’s amazing! Thankyouthankyouthankyou!”

Fate laughed as the two girls untangled themselves and sat up. The girl with the pastel skin seemed to be more alive than she’d been the entire night all of a sudden. The red gemstone glowed faintly around her neck as she laughed and pulled Fate back up again. “I”m glad I could help. So, care to show off what it does?”

Sonata blinked and quickly ran through her roster of known songs. Considering the epic power levels she could sense even more clearly now that she had her pendant back, a huge chunk of those songs, and what they were used for, went firmly into the Really Bad Idea category. At least, as long as she was around these people. But there had to be something she could sing...

She stopped and blinked again as a really subversive idea occurred to her. She could do Rainboom covers! “As long as Adagio doesn’t find out,” she commented under her breath with a grin. “She’d never let me live it down.” She touched the pendant and looked back at Fate. “Umm... I have grabby sisters,” she began, looking down at the red glow. “Is there any way I can prevent them from... you know...”

Fate grinned and nodded. “I know the feeling. Subaru’s sisters were a real handful for a few months a while back. If it wasn’t clearly labeled, they absolutely grabbed and ate it.” She winked. “I had to teach them not to do that with a few strategically placed hot peppers and wasabi rolls, but they got the hint eventually.” As the other girl giggled, Fate reached out and touched the stone. Her fingertip glowed. “There. I’ve put in the standard instruction guide for new mages. The TSA encourages us to share our knowledge with anyone who wants it, so don’t worry about it. And if you’re any good, you could learn the advanced stuff.” She waved around at the party environment. “I’m fairly sure there’s someone here who can make that happen, no matter where you’re from.”

Sonata blinked a few times. The image of her cackling maniacally while standing off Starswirl briefly filled her mind. Then a buffet’s worth of tacos marched by, playing their tiny musical instruments and banging drums enthusiastically, causing mage-Sonata to lose her focus and bounce off after the deliciously musical food. Starswirl picked up mage-Sonata in his magic once more, and threw her through the portal once again as the girl gleefully chowed down on tiny, terrorized Appleloosian food.

Sonata shook her head, clearing the image. She grinned at Fate’s confused look. “I’m sure we can. Don’t worry. Clearly, I need more tacos.” She considered songs, and focused on her crystal. If she was going to try the syrupy sweet feel-good songs the Rainbooms were fond of, she might as well go whole-hog and dive into it. Sort of like Adagio pulling out the stuff buried at the bottom of her tickle trunk. The stuff the openly trashy skank would never voluntarily admit to owning, yet still went on ‘dates’ wearing from time to time.

“Now... What fits the moment?” With a grin, she made her choice.

Reaching into the pendant for just enough power to start, she gestured to the side. Purplish energy swirled out and formed a mosaic behind her, suggestive of a bunch of girls in a band. They began to play music. So lost was she in the moment, the Siren failed to notice the projection didn’t glow the deep, poisonous emerald she was so accustomed to.

The first bars of “Legend you were meant to be” drew her into the music. She began to sing, enjoying the look of surprised happiness on the other girl’s face as Sonata’s singing voice, restored to its smooth, enticing potential by the magic, reached out and pulled the girl into the song with her.

I used to think that stories were just that
Set in stone, concrete as a fact
It didn't dawn on me
That I could change history...

Sonata’s voice reached out like a wave, calling others within its range. Other partygoers, hearing the song, drifted away from the main group to the girl singing in the yard outside. And if no one knew who she was, it didn’t seem to matter.

To one side, a beautiful woman of indeterminate age with a glowing gemstone in her forehead walked to the balcony and leaned against the railing, watching the girl with a mysterious smile on her face.

Now I know I'm writing my own song
Fight my way to the ending that I want
I'll turn a tragedy
Into an Epic Fantasy!

Fate’s eyes widened as she heard Sonata’s voice shift in the second stanza. It almost sounded like a second girl. Whatever Sonata’s talent with music, Siren or not, she had real skill.

Sonata watched with glee as the blonde’s expression shifted as she altered her voice slightly. This next part was going to *totally* freak her out!

Hey, hey, hey
You can be a hero (hero) too
Oh-oh-oh
Take my hand, I'm here for you
Come away with me
Be the legend you were meant to be
You'll always be Everfree!

In the crowd, Nanoha blinked in surprise as the mystery girl Fate was with somehow shifted her voice into a triple descant, apparently all by herself. And the chorus again sounded like an entire group of girls singing together. Making her way across the yard to her girlfriend, she continued to listen to this impossible singing voice as the girl sang of second chances and happy discoveries.

For herself, Sonata was lost in the music. This was exactly where she loved being. In the moment, with the music swirling through and around her. She could feel the pendant’s magic drawing on the emotions of the crowd. Soon, it would turn that into energy it could draw on, and feed it back to Sonata, empowering her still further. With nothing but the pendant and two sisters, they had conquered entire civilizations, once. She wondered what she could do with it now.

After a long second chorus, she focused on the magic. Shifting to approximate the entire Rainboom band would take some effort, but she needed to for this next segment.

There was a time when fear would hold me down
'Cause I let it chain me to the ground

Look at me now, I'm soaring high
It's never boring in the sky

When I know I've got friends on my side
Whatever trials, I'll take them all in stride

Together we will shine so bright
A radiant brilliance in the night!

The words flowed out of Sonata in a long rush, even the effort to shift her voice to sound sort of like the Rainbooms was almost meaningless against how good it felt. Then she became aware of it. The magic. Infused with their emotions and pouring back to her. About to fill her with power, like it always had before. She almost lost her place in the song as the tendrils finally reached the pendant, and began to fill her with energy.

Sonata’s eyes widened as she felt the energy pour in. It felt... different. Not cold and needy, like it always had in the past. Then, when the emerald energy reached her, it filled her with power, yes. But also a deep need for more. She was always hungry. No amount of power was ever enough to fill the need for more. And she had taken more. And more. And it always filled her with a deep need to drink deeper.

Not this time. As the energy poured into her pendant, she felt something she’d never felt from her power before.

Warm.

Instead of filling her with hunger, it seemed to fill her to bursting with warmth. She finished the song mostly on autopilot, but from the enthusiastic applause from the impromptu audience, she’d done it well enough.

Sonata cupped the pendant in her hands, and stared at it. The red jewel gleamed complacently in her hands. She could somehow tell it was entirely happy where it was. It was with Sonata, which meant all was right with the world. And yet, the energy it had just channeled back to her was like nothing she’d channeled before.

She could feel it inside. The energy felt warm and invigorating. She knew without needing anyone to tell her that her interrupted longevity was back, as were her other advantages. But that gnawing hunger was still gone. In its place, she just felt warm.

“Is it the song?” Sonata whispered to the jewel. Lacking a mystical intellect of its own, it just lay in her hand, glowing happily. “Is it the lyrics? Or what Fate did? Or is it,” she added with a twisted grin, “that that Rainbooms are actually *on* to something? Adagio,” she finished with a depressed sigh, “is really not going to like this.”

She looked over as Fate and her girlfriend approached her. “That was awesome!” Fate gushed. “How did you do that with the voices back there? I’m sure you didn’t cast any spells or anything.”

“I told you,” Sonata said with a teasing grin. “I’m a Siren. Music is what we do.”

Nanoha gestured at the people still drifting out of the house. “Feel like any more performances?” She grinned. “You’ve definitely got an audience.”

The Siren bit her lip and started walking out into the yard proper. She spun around and pointed at the two girls. “Tacos. After this. I definitely need more tacos.”

Fate laughed and tapped Bardiche’s crystal to her forehead. “Absolutely. Now go rock their world!”

Making her way out to the yard, she took in the expectant faces of a wide range of strange people. Being the center of attention was nothing new to her, it still filled her with that familiar anticipation as she cued up her next performance. Since the Rainbooms’ music worked so well last time, it made sense to pick something else. Heck, maybe cover their entire performance.

As Sonata began a very heartfelt rendition of “Hope Shines Eternal,” to mystical accompaniment, the woman on the balcony shifted to the side to make room for her older sister. The dusky-skinned goddess popped the last mouthful of something spicy into her mouth and chased it down with something definitely alcoholic. “So, that’s her, huh?” Urd shook her head slowly as Nanoha began to sing the chorus on the second pass while looking deep into Fate’s eyes, drawing a deep crimson blush from the blonde girl. “You are such a softie.”

Belldandy grinned and bit into her taco with a shrug.