Sonata Fortissimo

by MassDriver

Rating: mature
Tags: Equestria Girls, Sex, Sonata Dusk, Other
Length: 4697

To protect her boyfriend Silent Mic, Sonata Dusk grows into a 1500-foot-tall, hyper-muscled giantess.

Sonata loves to grow bigger for her boyfriend Silent Mic - and Silent Mic loves to see her grow. But there are new horizons in size and in bulk, as the two discover when giant monsters invade from another dimension.

Nourishing herself with Silent Mic's love, Sonata grows hundreds of feet tall, gathering strength in gigantic muscles to overpower - and devour - the invaders that threaten her little boyfriend's life.

Contains: Giantess, Hyper Muscle Growth, Soft Vore, Crush (no gore; crush victims are cartoonishly flattened), Sex

This story was a commission! If you want one of your own, see my commission policy and prices here. I can also be reached at massdriver77 {at} gmail {dot} com, or on Discord at MassDriver#3858.

I've also set up a Ko-fi! If you want to support my work but you're not looking for a commission, it's a great way to leave a tip!

All characters are over 18.

Cover image is an edited version of "Moka Hyper Buff commission", available on the artist Dagwam's deviantart page. Used without permission.

Published 2017-12-14 00:10:06 UTC
Last updated 2017-12-14 00:10:06 UTC

Chapter 1

“Wait,” said Silent Mic. “Hang on.”

Returning from the bathroom, Silent Mic was stopped in his tracks by the sight of Sonata Dusk - his girlfriend - lifting the living room couch over her head.

Silent Mic’s couch was a bit heavier than average, thanks to the mechanisms that permitted it to fold out. One hundred and eighty-five pounds, give or take. And Sonata Dusk was a slim girl, who - in addition to weighing considerably less than the couch itself - didn’t have any muscles to speak of.

Of course, Silent Mic had seen her perform numerous feats of strength… but only when she’d grown into a giantess. As a siren, Sonata had the power to absorb love - his love - and turn it into size. Standing at twenty feet tall, Sonata was stronger than anyone alive, and she’d proved it by fighting to protect Mic. She’d beaten - and consumed - plenty of tough customers, and her strength was not to be trifled with.

But right now, Sonata wasn’t a giantess. Her height was south of six feet, and her limbs were scrawny… and yet she was lifting the couch over her head like it was a hollow prop. And she’d paused whatever she was doing to turn and look at Mic, waiting on him to finish his thought.

“Are you always this strong?” asked Silent Mic, finally.

“Nah,” said Sonata, “But I dropped my phone between the cushions. And I think it’s stuck in there somewhere? So I used a little bit of your love to make me stronger.”

“Oh,” said Silent Mic. “So you don’t need to get bigger, necessarily? Or even, like, grow huge muscles?”

Sonata laughed. “Ooh, that’s a fun idea!” she said. “I could grow muscles. I can be big and buff!” She fluttered her eyelashes in Silent Mic’s direction. “Do you want to see me like that?”

SIlent Mic tried to imagine a buff Sonata. In his mind, he added a layer of toned muscle - and then he imagined bulging thighs and biceps, with rock-hard abs in between… his imagination was going deep into this previously unexplored territory, packing on more muscle, thicker muscle, every inch of her swelling with strength… “Yeah,” said Mic, “That sounds kinda cool.”

“Awesome!” said Sonata. She closed her eyes and lifted her head slightly, seeming to breathe in. Silent Mic did what he usually did when Sonata needed to grow: he sent his love to her, focusing his mind on his feelings and sort of directing them at Sonata’s body.

Sonata’s head began to climb higher, and Silent Mic’s heart raced at the familiar sight. Even though it wasn’t a surprise anymore, it was a thrill to watch his beautiful, magical girlfriend grow larger. But this time she wasn’t just growing taller - she was growing wider. Her head stayed just the same, but her shoulders spread apart, making room for the muscle mass that sprouted up around her neck and shoulders. Below her plaid skirt, her thighs expanded outward, each set of hamstring growing into thick, powerful cords of muscle. Inside the sleeves of her stylish purple top, her biceps and triceps swelled into bulging mounds.

There was an abrupt riiip as her sleeves split open, utterly destroyed by the unstoppable growth of her arms. That was a surprise; Sonata usually had no trouble making her clothes grow along with her, but this time they weren’t keeping up with her. Her top, held together in the front by three blue buttons, was struggling to keep her swelling body contained, stretching and bunching as she expanded. As Sonata grew past seven feet, the herm of her top began to creep upward, exposing her navel… as well as the rigid, powerfully defined six-pack that now framed it.

At seven and a half feet tall, Sonata Dusk boasted a physique that would put any bodybuilder on the planet to shame. Every muscle beneath her pale blue skin was thick, bulging, and proudly defined - but her growth had preserved the more feminine aspects that Silent Mic loved best. Her face was unchanged - still rounded and innocently smiling. Her breasts, although pushed forward by a layer of muscle underneath - had only grown rounder, in contrast to the pure muscle that had filled out the rest of her body. And Silent Mic could see an even bigger rump pushing out the back of her skirt, two wobbling globes that no doubt concealed a world-class set of glutes. Silent Mic was speechless, gazing upward at his girlfriend - a woman who commanded more power than anyone else on earth.

A moan escaped Sonata’s lips, becoming louder as her lungs grew bigger and more powerful. She wasn’t done growing, Silent Mic realized - and that wasn’t too surprising, since he’d seen her grow to twenty feet tall. But she wasn’t just getting taller; her muscles, already close to the apex of human potential, were still swelling bigger. As her chest expanded, the bottom two buttons flew off… but the last one held fast, preserving Sonata’s modesty

Silent Mic couldn’t help himself; he approached Sonata’s beautiful, fearsome body and placed his hand on her thigh. Her smooth skin was rumbling with power, the muscles shifting underneath as they grew to impossible sizes. Beneath his fingers, individual muscles swelled to the size of bowling balls and beyond. He placed his other hand on the opposite side of her thigh, feeling it widen until it was twice as big around as his waist - and even still, it grew.

“Ooh, this feels good,” moaned Sonata. “I’ve never tried this before… do you like me big and strong, Silent Mic? Mmm, you like a girl who can fight for you, don’t you? A girl who can keep you safe…”

“Yeah, I do,” whispered Silent Mic. He leaned his body against Sonata’s thigh, feeling its growth pushing back on his whole body. Her leg didn’t move an inch, even as he leaned all his weight against it; it was as wide and sturdy as a tree trunk, planted firmly on the floor. “Sonata, you’re the strongest, most beautiful girl in the world… I know you can keep me safe from anything…”

“Mmm, keep stroking my big, strong muscles, Silent Mic,” purred Sonata. “Being huge feels so good… and being strong makes it even better…”

Silent Mic ran his hands along the surface of her thigh, feeling her growth rumble and shudder to a halt. Her thigh was three times the width of Silent Mic’s waist now, her leg muscles swollen to a size that no human could ever hope to attain. Her feet, like her head, were proportioned normally - but her ankles bulged outward, wrapped thick with muscle, and her thighs were even wider. Her arms were just as thick, every inch packed tight with thick, round, beefy muscle. Every muscle had grown, even ones that Silent Mic hadn’t known existed; her neck muscles had grown into two gigantic humps that overshadowed her head.

Some might have found her appearance strange… but Silent Mic had come to admire her strength. Seeing her body swollen with strength, bursting with it… it only made her more beautiful. And it didn’t hurt that her breasts and her ass were bigger than ever, smooth and round and gently wobbling with each breath she took. Her clothes were barely sufficient to contain her tremendous body - her top was still holding on by one straining button, and her skirt completely failed to conceal her butt.

And while Silent Mic had done nothing but gaze slack-jawed at his beautiful, growing girlfriend, Sonata hadn’t opened her eyes since she started growing. “Woooah!” she said, finally looking down at herself. “I’m frickin’ huge! I wasn’t even trying to get this big!” She looked down at Silent Mic, with a mischievous gleam in her eyes. “Just how much love were you sending me, little guy?”

“Uh, a lot, I guess…”

“Oh, geez,” she said, testing her elbows, “these muscles are so big I can barely bend my arms!” She extended both arms in front of her, grunting as she fought against her own bulk. “Aw, man!” she whined, “I've got these giant boobs and my hands don't even reach ‘em!”

Sonata leaned forward, gazing hungrily at Silent Mac over her immense rack. “I guess you'll just have to touch ‘em for me…”

Her giant, bulging arms swung down, closing in on Silent Mic, and he flinched, cowed by her strength. Sonata was a great girl, but she could be a little careless… and if she had more strength than she knew what to do with, Silent Mic could be crushed flat just as easily as the thugs she’d dispatched in the past.

But her hands clasped him gently, her fingers encircling his waist and lifting him up to chest level. “Woah!” she gasped. “Silent Mic, you weigh, like, nothing!” Silent Mic blushed, feeling very small - but very safe - in Sonata’s hands.

“Come on and grope these boobies for me, little guy,” said Sonata, bringing him as close to her bust as her arms would allow. “This body is super cool, but I can barely touch it! So I'm gonna need you to touch me all over…”

Silent Mic gulped and extended his hands to grasp Sonata’s tits. They were exactly the opposite of the powerful leg muscles he'd felt as she grew; where those had been as hard as steel, her breasts were pillow-soft, yielding to his touch. He pressed his hands into her massive mounds, sinking them into her flesh up to his wrist. Sonata sighed with pleasure, and Silent Mic ran his hands along her bust, sneaking his hands beneath her top to feel her bare skin. “Sonata,” he whispered, “your body is incredible.”

Sonata laughed. “I haven't even done anything yet!” she said. “But I should do something incredible with this body. Maybe we can go out and see what kinda stuff I can lift… unless you'd rather just let me carry you off to bed…”

This proved to be a difficult choice. Being carried off to bed had obvious appeal, but watching her use those big, beautiful muscles would be amazing foreplay. Silent Mic weighed his options, his hands still gliding over the soft skin of Sonata’s breasts… until an earth-shaking thump interrupted his thought process.

“Woah,” said Sonata. “That, like, wasn't me.”

Another thump shook the apartment. More followed, in a rhythm that sounded eerily like footsteps. “Sonata, I'm kind of worried…” said Silent Mic.

Sonata looked down at him sympathetically - with an expression that Silent Mic recalled from the last few times she'd protected him from danger. “Well, we can't have fun if you're scared,” she said. “Let’s see what’s making all that noise.”

She stuck Silent Mic under one arm, holding him between her bicep and her torso - but even as she pinned his body between two thick, steely muscles, Sonata held him gently. She walked to the apartment’s front door, and in one smooth motion she crushed the doorknob in her hand and ripped the door off its hinges.

“Oops,” she giggled, tossing the door aside and gradually maneuvering her burly body through the doorway. Silent Mic stammered, unable to articulate a protest - but as it turned out, the door was doomed from the start. Sonata’s ten-foot, musclebound body couldn't get through the doorframe without widening it, cracking the wall in the process.

Once they were outside, it took no time at all to discover the source of the quakes. Distant sirens drew their attention towards the outskirts of the city, where some kind of immense crustacean - red-shelled, with wildly snapping claws - was crushing buildings underfoot.

“I smell magic,” said Sonata. “That’s some kinda magic monster, here in this world to conquer and destroy!” Her face twisted into a scowl. “That's unforgivable!”

It occurred to Silent Mic that Sonata’s description applied fairly well to herself (at least, before her confrontation at Canterlot High), but other concerns were on his mind. “You're not gonna try and fight that thing, are you?” he asked. “Even if you grow to twenty feet, that thing’s… way bigger.”

Sonata chuckled. “Oh, Silent Mic,” she said, “twenty feet isn't my maximum! It's just a convenient stopping point that lets me eat my enemies, navigate most human-sized environments, and fool around with my boyfriend! I can get bigger.”

“Oh,” said Mic. “Like… how big?”

“Well, it depends how much love you can give me,” said Sonata. She held Silent Mic with both hands, lifting him until his head was level with hers. “Give me everything you got, little guy.”

She pulled him in for a kiss, bringing his mouth to hers. For a woman so buff, she was still soft where it counted - and that included her lips. Silent Mic melted into the kiss, his mind instantly awash in thoughts of love. He did his best to focus his love into the place where their lips touched - and just like always, her body began to turn his love into growth.

But this time it was terrifyingly fast, a sudden upward jolt as her burly body expanded upward. Her lips soon outgrew his, the soft blue skin overtaking his chin, then his nose - she was kissing his entire head, and he kissed her right back, still sending his love to empower her beautiful body.

With one finger, Sonata gently nudged Silent Mic away from her lips, sending him falling backwards onto the palm of her hand. Laying prone, he looked up at her face. She wore a comforting, loving expression that Silent Mic had come to cherish - but now it was towering over him, bigger than a billboard. She'd grown into a true giantess.

“Wow!” said Sonata. “You keep giving me so much… it feels so good when you fill me with your love and make me bigger, Silent Mic…”

Silent Mic looked in the direction of the sirens. The crustacean was still rampaging… and it was still bigger than Sonata. He estimated Sonata at a hundred feet tall, which was a breathtaking height for his buff, beautiful girlfriend… but it still put her at a disadvantage. “I don't know if it was enough…” he muttered.

“Wha?” said Sonata. “Oh, don't worry… I'm not done growing! You gave me plenty of love… and if I keep you close, you can keep right on giving it to me!” She lifted him higher, setting him down in a cleft between two neck muscles. It was wide enough for him to sit in comfortably, and the bulging muscles rose so far past her shoulders that Silent Mic was seated right next to her ear. Her two-tone ponytail was resting in the same cleft, and Silent Mic grabbed a handful of her hair, ready to hang on if he got jostled loose.

“All right, monster,” growled Sonata. “Get ready to get crabbed!” She charged toward the crustacean, her footsteps producing tremors almost as powerful as the monster’s. She was still growing, Silent Mic realized - the monster’s eyestalks weren't looming quite as tall now. Mic focused on sending her more love - although he was slightly distracted by her use of the phrase “get crabbed.” What pun had she been going for, exactly?

It likely didn’t matter; the monster’s eyestalks betrayed no sign of intelligence as they swiveled to look at the oncoming giantess. But it instinctively raised its claws to intercept her charge - and although Sonata was able to grab its snapping pincers by the wrists, her arms trembled as she and the beast struggled against each other. Strong as she was, the monster was still a good thirty feet taller. Silent Mic watched the struggle - watched the monster force Sonata’s arms downward - and started to panic. She was losing.

“Ooh,” growled Sonata. “This guy’s strong. Well, I have enough of your love stored up, babe… time to use it!”

Sonata’s body surged with growth, shooting upward even faster than before. Silent Mic’s stomach dropped, and his head swam with vertigo - but he kept his eyes on the struggle between Sonata and the monster. As she approached its height, she began to overpower the crustacean - and as she shot past its height, it ceased to be a struggle at all. She grew big enough that she could hold both its pincers closed with one hand - and as she kept growing, its legs left the ground, kicking furiously as she dangled it in midair. At five hundred feet, she held the monster in front of her face - and Silent Mic watched her enormous, slick tongue emerge from her mouth and lick her lips.

“Mmm, seafood,” she said. “I mean, its magic smells like it’s from the void outside of time, but that’s kind of like an ocean…” she opened her mouth wide, extending her tongue like a runway for the struggling monster. Silent Mic, seated beside her head, felt a shiver of arousal go through him at the sight of that huge, wide-open mouth. Sonata’s power to consume her enemies was a turn-on for him, and seeing her mouth open so big and so wide was… amazing.

On the other hand… “Raw shellfish?” said Silent Mic. Also, the “void outside of time” thing didn’t sound super healthy, but he wasn’t sure how to articulate that concern.

Sonata didn’t seem worried, though; as her cheeks bulged, she turned to Mic and waved dismissively. She raised her head and started to swallow, and Silent Mic got a front-row seat to watch the struggling bulge descend her throat. The monster was big enough to stomp buildings, and Silent Mic’s love had made Sonata big enough to gulp it down whole.

Nearer the city, the sky crackled, and Sonata turned to look. There was something over the city that looked like the aurora borealis - except dark - and a furry claw emerged from inside it. A snarling, toothy maw followed after it - and even from Sonata’s shoulder, five hundred feet off the ground, its scale was intimidating.

“Ooh, this’ll be fun!” said Sonata. “Gonna need a little more love, cutie. Pretty quick!”

And she took off running. The muscles in her legs flexed, bulging bigger as they tensed - and then she kicked off from the ground with a burst of speed that knocked Silent Mac back in his seat. He was doing his best to send Sonata his love, hoping that it wouldn’t be tainted by the fear he was also feeling.

And his fear spiked as a huge lupine beast crawled from the dark aurora, with another one hot on its heels. As soon as the first dark-furred wolf fell to earth, crushing a city block beneath its paws, the next one pulled its shoulders through the tear in the sky. And another one, and another - it was a whole pack of monstrous wolves, all of them a couple hundred feet taller than Sonata.

“Furry, huh?” said Sonata. “I don’t feel like swallowing something hairy. This’ll be more fun anyway…” As she closed the distance, she surged with growth again, until the wolf pack barely reached up to her boobs. One of the wolves charged her, running on four legs and leaping at her with its toothy maw wide open.

But by the time their bodies met, Sonata had grown to twice its size - and no part of her body was small enough for the wolf to get its mouth around. It bounced off her abs, falling to the ground, and Sonata stepped forward, planting her feet on either side of the beast, putting it squarely in her immense shadow.

And then she brought her legs together, flattening the creature between her thighs. She pulled her legs apart, and the beast’s flattened body floated to the ground - still huge, but otherwise harmless.

The other three wolves seemed undaunted; they charged as a pack, sending rubble flying as they moved to surround her. Sonata just smiled, lifted her arm, and let herself drop, bringing her immense elbow - and all the weight her enormous muscles put behind it - down on top of the nearest wolf. Silent Mic, clinging to her ponytail, managed to avoid falling.

The last two wolves hesitated, their paws scraping furrows in the city streets as they backed away… but Sonata didn’t give them the chance to turn tail. She flexed the arm she’d brought down on the wolf, launching her body in the other direction and turning her body so that her enormous round breasts landed right on another giant wolf.

After her bellyflop, she lifted her body off the ground with both burly arms - revealing the dark, flat, furry pancake the beast had become. There was also an entire city block squashed flat beneath it, but Sonata wasn’t worrying about that - instead, she lifted herself into a handstand with nothing but the strength of her arms. Then, as Silent Mic braced himself and held tight to her ponytail, she bent her elbows - and then flexed them hard.

Using the full strength of her arms, she launched herself into the sky, leaving two deep craters where her hands had been touching the pavement. She soared up, past the clouds - and then bent at the waist, aiming her gigantic jiggling butt at the earth.

The last wolf began to flee, scampering for the hills, and it looked like Sonata would miss… but on her way down she expanded again, widening her beautiful round bottom - along with every other part of her - to almost twice its size. Her left cheek flattened the wolf - along with several city blocks.

And then she stood, rising to her full height - which was much taller now than the last time she’d stood on solid ground. The tallest building in the city was just at eye level with her - which Silent Mic knew made her about 1,500 feet tall. “Ooh, Silent Mic,” she said, “I’m so full of your love, sweetie… it feels so good to be able to use all of it to grow… and get buff.”

“You’re beautiful,” said Silent Mic. “You’re so big and powerful… I can’t believe my love helped you do that.”

“Your love does all sorts of things for me,” said Sonata. “But being this big feels so good… and there’s one thing I really want you to do for me right now.”

She held her hand up to her shoulder and leaned her body forward. Silent Mic let go of her ponytail, letting himself fall into her hand. “How about you strip down and show me that cute little body?” she said, and Silent Mic complied, pulling off his shirt and his pants and dropping them onto Sonata’s palm.

“Oh my gosh,” Sonata gasped, her gigantic eyes shining as she stared down at his tiny, naked body. “You have never been cuter, SIlent Mic. I need you right now…” And she lowered her hand down past her tits, down past her abs, all the way down to her panties. Like the rest of her clothes, they’d been stretched to the limit by her growth; the fabric was pulled tight enough that he could see the enormous slick lips of her pussy through the pink material.

She pulled the waistband away from her body and gradually lowered the hand that held Silent Mic into her panties, bringing him closer and closer to her towering pussy lips. “Oh, wow…” he said, filling his lungs with the intoxicating feminine musk of her womanhood. “Sonata, your body is so amazing, but… I don’t know if I can really do anything for you…”

But he was about seven hundred feet away from Sonata’s ears, and she wanted this a lot. Her hand descended into her panties, pressing Silent Mic’s entire body into the slick surface of her gigantic clit. “Ooh, I can feel that little body in my clitty,” moaned Sonata. “Mmm, it’s good…”

Towering above the city, the hyper-muscled giantess held her hand in panties, moaning as her tiny boyfriend squirmed against her clit. But her celebration was premature; the dark aurora crackled again, and two scaly red hands tore their way out - followed by a lizardlike and yet feminine face. Cruel green eyes surveyed the city, and her immense toothy maw opened wide.

“Mortals,” growled the monster, “One among you has trifled with magic beyond your ken, birthing a rift that has permitted-” she paused, squinting at Sonata. “I’m sorry, who are you?”

“Kind of in the middle of something,” gasped Sonata - and with the hand that wasn’t holding her boyfriend to her clit, she reached toward the rift and grabbed the lizard monster by the neck. She squawked as Sonata grabbed her and pulled her body through the rift, and she struggled, kicking and clawing as Sonata pulled her towards her mouth - but her flailing claws and whipping tail lacked the strength to fight back against the goddess of muscle that Sonata had become.

“I wouldn’t mind another meal while my little man tickles my clit, though…” said Sonata, holding the monster by the neck and surveying her body. There was no need to outgrow this newcomer; at nine hundred feet, the big red lizard was tiny compared to Sonata. She was also kinda hot - just below her shoulders, her scaly underbelly curved into a prominent bosom, and underneath her tail was a thick, scaly red rump.

But fine as these features were, they weren’t long for this world. She shoved the lizard monster’s head into her mouth, then grabbed her by the shoulder and fed the scaly titan deeper into her throat. Through a full mouth and a bulging throat, Sonata moaned, moving the hand that held Silent Mic in slow, small circles over her clit.

Silent Mic was in total darkness, held tight between Sonata’s hand and her immense clitoris. He writhed against the slick, fragrant flesh, using all his strength to pleasure his gigantic, immensely powerful girlfriend. It seemed impossible that someone as small as him could make her enormous body feel anything… and yet he could feel her hips gyrating, her body moving rhythmically as she moaned and whimpered from hundreds of feet above. She was clearly getting somewhere - and Mic was coming right along with her, grinding his cock against the wall of flesh in front of him.

Sonata had her hand around the lizard’s ass now, groping the round, scaly cheeks as she pushed the beast further and further down her bulging throat. Her hips began to twitch, and the walls of her pussy clenched as her body ascended towards climax. Silent Mic was small, smaller than an ant to her - but his body was radiating love, and her magic could do so much with that. When she wasn’t using it to grow, she could turn it into stimulation. Silent Mic was like a tiny little vibrator, and he was putting out intense, thrumming waves of love. The feeling pounded at her clit, shooting deeper into her core, until the dam finally burst and her pussy pulsed in an explosive climax. Silent Mic, shoved deep in her panties, ground his hips against her throbbing clit - and felt his cock spasm as he shot his load onto her gigantic love button.

Sonata fell to her knees, gulping down the giant lizard’s kicking ankles and thrashing tail - and once the uneven bulge slipped down her throat, she finally cried out, shaking the city with her voice as her climax passed its peak and began to wind down.

Sonata was flushed, breathing heavy, her forehead slick with sweat - and even though her body was fifteen hundred feet tall and swollen with gigantic muscles, she felt weak as the feeling faded. She let herself fall backwards, managing to crush some buildings that were still standing. “Silent Mic,” she gasped, slowly moving her hand inside her panties. “You’re safe now, Silent Mic. I love you so much…”