ONE PUNCH MARE

by Slippin_Sweetie

First published

After his final battle with Boros, Saitama is sent to the magical lands of Equestria. Where not even he is sure if was isekai'd or just displaced. He's hoping the latter for his worlds sake...and Genos.

One Punch Man x My Little Pony fan fiction. Mostly just a single action and comedy scene made into a shortfic. Trigger warning for blood and character death.


Please check out my other work, and have a great day. PLUS ULTRA or something.

Fully Featured and HOT on 02/6/23, 02/7/23 you crazy bastards really wanted a chapter two.

The Hero(Ine)

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A lot of people say that the pursuit of power is the mark of villainy and evil. History and politics have events and circumstances that seem to reinforce this idea. However, in my opinion, I think there’s a price for power. For me, it was my hair…and my spirit. I have unlocked a great power to defeat any man or monster with one single punch, and honestly? It makes this hobby too easy.

What’s the point in being a hero for fun when there’s no fun in it? All I ever wanted was to feel the thrill of battle just one last time or just…anything. At least I got that last part, I think because honestly, the only emotion I’m feeling right now is…uh…weirded out….where are my fingers? Where is everyone? The space pirates, the other heroes, my hands? Did I…no way I would’ve felt pain or a cold feeling if my blood was drawn unless I was entirely destroyed by that weird alien psycho.

I think I might’ve broken something or really messed up myself because it feels like I have four legs. At least I’ve gained the ability to smell water, I guess. Better trek through this forest…


Saitama trotted through the wilderness on the outskirts of Ponyville, and, finding his way to the water with his new equine nose, the apathetic hero discovered a shockingly new revelation.

“Holy crap….I’m a horse….” he said exasperated, “.....maybe Boros changed me into a horse with his power, I guess?” the earth pony clasped his mouth as if his throat was spewing bile, “Am I a woman too now!?” she said in a rare moment of frustration and disbelief.

The earth pony examined her reflection, instinctively knowing that, in fact, she was a mare with a bit of relief that her costume was still attached to her and, unfortunately, her baldness too remained. Saitama stroked her bald head with his hoof feeling her soft white coat push against his hoof.

“This is really weird…but I’m sure the Hero Association has a fix to body changes like this, right?” Saitama thought as she traveled aimlessly down a lonely dirt road, “At least make me a boy horse right?” he pondered, attempting to rationalize and compromise with his current predicament.

A set of piercing screams echoed through the forest as Saitama’s ear twitched, immediately racing off toward the sound, a wave of relief washing over her knowing her powers still remained. Although she wondered how she could punch with no fists or hands. Maybe this was a blessing in a way. Perhaps the challenge Saitama always sought after was now given to him in this new form.

It didn’t take long for the formerly human superhero to stumble into a small village full of pony creatures screaming and running in terror as a large Centaur creature seemed to tear apart and effectively destroy the town in a fit of rage.

“TWILIGHT SPARKLE!” roared the towering creature, “WHERE ARE YOU? REVEAL YOURSELF, OR I WILL DESTROY EVERYPONY IN THIS VILLAGE AND WIPE THIS PUTRID TOWN OFF OF EQUESTRIA’S SURFACE!”

“No fair; why does he get hands?” muttered Saitama.

“ARE YOU SCARED? SCARED THAT I MANAGED TO TAKE ALL OF THE ALICORN MAGIC FROM YOUR PRECIOUS PRINCESSES?” cackled the monster, “WELL AREN’T YOU GOING TO BE THE PRINCESS THAT YOUR PONIES NEED OR AM I GOING TO HAVE TO CRUSH A FEW PONIES TO GET YOUR ATTENTION!?”

Saitama squinted disapprovingly at the monster, “Ok…that’s totally a monster,” he thought to himself, “At least I can still be a hero…and if I remember correctly, alicorns are magical…maybe he’s super powerful.”

Her heart pulsated in excitement as a smile grew across the mare’s face, “Maybe he’ll be a challenge….”

The little earth pony trotted up before the giant red monster, “Hey.” casually greeted the formerly human hero.

The large red centaur was taken aback by the plain-looking pony’s forwardness, quickly noting her yellow costume and red boots. A devious smile curled on his lips as he erupted in laughter, “What’s this!? Did Nightmare Night come early this year!? What is the meaning of this? Are you TRYING to get yourself killed, powerless earth pony!?”

“You said you were powerful, but all I see is just a brute trashing a small town with strength alone…why don’t you pick on someone your own size,” Saitama said lamely.

The centaur was befuddled, hunching over to meet the pony’s eyes, “Are you trying to get yourself killed? NOPONY COULD HANDLE MY POWER; NOW STEP ASIDE OR PERISH!”

Saitama quickly snapped up on her back legs as she cocked her right front leg and made a punching motion with her front leg, slamming her hoof into the creature's chest and sending the beast flying into the air and out of the village.

Saitama looked at her steaming hoof as she fell backward, losing her balance after a moment of being on her back legs, “Oh…guess he wasn’t that powerful after all...” she said with a disappointed tone.

“D-do you even know who that was!?” shrieked a mare peering behind from a pile of rubble.

“.....no….was he a hero? Wait are you guys secretly evil?” Saitama asked, now feeling a bit nervous that he potentially pumbled a fellow hero.

“N-no! That was Lord Tirek! He’s trying to steal all of Equestria’s magic so he can destroy the world as he knows it and rule over these lands with an iron fist!”

“Oh… ok.” nodded Saitama.

A large beam of orangish red magic collided with Saitama from above, creating a crater where she stood as the mare felt herself slammed into the dirt as an unbearable heat encompassed her entire being. Before, the mare was lying on a pile of soil and rock in a few feet deep in a hole.

Tirek fell from the sky as he crashed into the crater and stood over Saitama, “I don’t know what magic you possess, earth pony, but a mere distraction like yourself isn’t enough to stop ME!”

Saitama slowly blinked, “....So you’re Tirek, right? That’s what that horse told me.”

Tirek gritted his teeth as he clenched his fists, “DON’T YOU DARE PRETEND YOU DON’T KNOW OF MY TERRIBLE POWER PONY; I HAVE CLAWED MY WAY FROM THE PITS OF TARTAR-”

“Wah wah wah, you’re really starting to bore me…” complained the mare as she slowly climbed onto her hooves and limbered up, “It’s always the same thing with you monsters no matter where I go. Spare me your speeches and shut up and fight.”

Tirek threw his fist toward the mare as Saitama quickly caught the creature’s massive fist with her tiny hoof, easily holding Tirek’s immense strength back.

Tirek strained as he stared at the pony beneath him with disbelief, “What is the meaning of this!? What spell or magic is this!?”

Saitama glanced around the destroyed village, “....you think this place has a market?....Or had one before you showed up.”

Tirek growled before pulling his fist away, “Pathetic little earth pony, you think your jokes are funny!?”

Saitama looked up at Tirek, “I wasn’t joking…lets finish this up so I can get something to eat. I’m starving….”

Tirek charged a massive beam of powerful magic in between his horns as his blood boiled red hot, insulted and shocked by the sheer dismissive nature of this one single earth pony, “Your head will be ripped from your body, earth mare….”

Saitama hobbled on her back legs before jumping up to meet the centaur’s face, “Consecutive Normal Punches,” the mare said calmly before unleashing a flurry of ‘normal’ punches into the monster's face.

Tirek felt his face twist as he felt his jaw break and be forcibly put back in place by these ‘normal’ punches, quickly firing his hyper beam of magic into the pony before clasping at his face, feeling something warm pour from his nose and mouth….his…blood?....this pony made him BLEED?

Saitama flew backward, crashing through several houses, walls, windows, and furniture as she pondered what to have for dinner later. Again pulling herself up from the rubble, she shook off whatever dirt or debris managed to attach itself to her body. Taking note of her now tattered cape.

“Oh…you tore my cape.”

Tirek adjusted his jaw as he flicked the blood off his fingertips, “Perhaps I have underestimated you, pony, but now I see you have left me no choice but to use the raw power of the Sun and Moon Goddess...” the centaur raised his arms as the sky changed from day to night. The sun and moon swirled in the sky as day and night changed seamlessly.

Saitama looked up at the sky changing rapidly, raising her brow at the beautiful cycle of day and night moving so seamlessly despite the chaos and unnatural nature of it all, “Ok.”

Tirek summoned all of his magical ability and energy into a massive orb several feet tall and wide that burned wildly like an uncontrolled ball of flame, its flames flickering with the colors of the rainbow.

Saitama’s gaze darkened, “I guess it’s time to get serious…” she’d awkwardly hoisted herself on her back legs before sprinting toward the beast leaping up into the air as she cocked her front legs back, “Killer Move: Serious Series, Two-Handed-er…Two-Hoof?...Hooves...Two-Hooved Serious Punch.”

Tirek grasped the celestial magic ball of fire with his hands, its heat and power singeing his palms as he grit his teeth and winced, screaming with all of his might, he slammed the massive orb into the mare, "I WON'T BE BEATEN BY THE LIKES OF YOU, PERISH!"

A massive white light blinded onlookers as a gigantic explosion of color erupted with a colossal aftershock blowing an enormous gust of air. Standing before Ponyville was the single bald mare with a steaming set of hooves standing on her back legs.

“...I think I overdid it.”

Tirek strained his once pronounced muscular figure gone; all that remained was a shriveled and gray creature dying in the freshly formed crater the two had created from their brief and deciding encounter.

The monster let out a labored breath as he spat a wad of blood-infused mucus, “...What are you?... How could you defeat me with just punches…I had….I had the power….of the alicorn’s and all of the unicorns in Equestria were drained of their magic…how?....who are you?”

Saitama carefully got down on her front hooves as she looked over at Tirek, blinking, “I’m just a hero for fun.”

Tirek laughed, slamming his fist weakly into the ground beneath him, “R-really?...heh….at least there is some humor in my death…..” the centaur said before letting out his last breath as his dull eyes stared lifelessly at Saitama.

Saitama winced as he trotted over and carefully closed his eyes, “Creepy.”

A massive portal opened as six ponies clad in jewelry stepped out, “Tirek! We-....what the heck happened here!?” cried the purple alicorn.

Several ponies would come out from the woodwork to cheer and exclaim the return of their Princess and their newfound savior.

Saitama sighed, “This is exactly what I didn’t want.”

“Don’t worry, Saitama!” cheered the pink pony, hopping over to the mare, “This is probably just a One-Shot!”

“Oh.... ok.”

Three Weeks Later And Saitama's New Students.

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Well, I live in a world of talking horses now. It's been a few weeks since I beat up that Tirek guy. Apparently, this wasn't the first time he tore up Ponyville or whatever. During that time, I meet two freaky-looking big horses with colorful manes and tattoos on their butts. Apparently, they never seen such a powerful earth pony? Basically, a normal horse with such a powerful punch, they also didn't understand why I didn't kick or 'buck.'

I basically told them I was fighting a giant alien bad guy and his space armada before I ended up here. Celestia, the white one, thinks I died or something? But the blue and black one says I was most likely transported from the sheer power of Boros' Collapsing Star Roaring Cannon and my Serious Punch sent me through space and time.

In other words, I got isekai'd or displaced like the manga I read back in my old apartment. But things aren't so bad. At least life here isn't nearly as boring or mundane. Seems like everybody here has some sort of exceptional talent that gives them power or something? Maybe it's like a Quirk or Superpower? I dunno, I have trouble listening to the purple girl talking, I sorta zone out. Speaking of ponies, apparently, they have Superheroes, six of them, and two powerful Gods or whatever.

The purple one seems pretty strong with magic. She's alright, I guess. She seems the most interested in me for my punches. I told her all I did was one-hundred push-ups, sit-ups, squats, and a ten-kilometer run. She didn't believe me like everyone else I ever told about my power's origin.

Then there's the blue one; I really don't like that one. She's like Tatsumaki except even more annoying; I really don't like her voice. Apparently, her superpower is loyalty? Honestly, I thought it'd be the fact she can fly at supersonic speeds.

Then there's the white and orange ones, the really lame ones. Honestly, I think those two could be beaten by Mumen Rider or at least a low-class B hero. But at least they're not too terrible, the white one made me some clothes since I don't like being naked and my suit is only meant for hero runs.

The orange one is pretty nice. I can't get past her goofy accent, though. I can't listen to her half the time because I'm fighting not to laugh at her accent. But she's nice, at least. But the pink one? Pinkie Pie? She creeps the Hell out of me. She just pops up out of nowhere; I can't get away from her, either. She can keep up with me. Running at supersonic speeds and jumping to the moon didn't even phase her.

God, her voice is annoying; she's worse than the blue one. It's so damn irritating and squeaky. I just want to bury my head in cement to spare myself from her tirades. But at least Fluttershy is ok. She's the only one that can be quiet and doesn't press me about my power, origin, or old life. I hate having all this attention on me, I spent my whole career as a hero avoiding the limelight, and now I'm the talk of the town.

Which is why I now bunk in her cottage for now, at least. I was going to live with purple girl, but her pet talking lizard weirds me out too much. It's ok; she keeps the place clean and runs an animal sanctuary. I guess I'll stay in Ponyville for a bit til I can get enough Yen-Bits saved up. I think I'll wander this place for a while and look for a way back home. Apparently, this world is full of monsters and villains looking to ruin this land. But...I made the mistake of assuming ALL monsters were evil, though. When I accidentally punched Fluttershy's boyfriend?...Best friend?.... Acquaintance. Discord. I was glad he survived a normal punch, but, uh… let's just say I'm not making friends with that guy any time soon…Also I keep coughing up mints since that day.


Saitama sighed as she hauled the last load of apples to the wagon inside the large red barn. Straining as she sat up on her back legs to rub her back. The only thought in her mind was dinner, how she craved some eggs on rice. Apparently, equines don't usually eat fish, and much to her dismay, Saitama would not be having any discounted fish or crab any time soon.

"Er, excuse me?" called a familiar voice.

Saitama turned around to a trio of fillies standing at the doorway, "We were just wonderin' if you could help us?" the yellow one asked politely.

Saitama shrugged, hobbling slightly as she quickly fell back on her front legs, "Uh…sure, kid, what's up? Lose your doll or something?"

Her face scrunched up to an annoyed look as she snapped back, "I don't play with dolls!"

The orange and white fillies next to her chuckled as the orange one peered over, "Sure you don't, Apple Bloom!"

"Ah, shad up, Scootaloo!" whined Apple Bloom.

The white filly quickly shoved the two aside, "Listen, we just need help getting our Cutie Marks, and we were wondering, since you're really strong, maybe you could give us advice for a cutie mark?"

Saitama paused as she looked down at her flank, "Oh…you mean this tattoo on my butt?"

The girls laughed, "It's not a tattoo, silly; it's your Cutie Mark!" explained the white filly.

"Don't laugh at me for not knowing your silly names!" Saitama let out an annoyed twitched, "uh…what are your names again?"

"I'm Apple Bloom, and this is Scootaloo and Sweetie Belle," explained Apple Bloom

"Ok," replied Saitama dryly.

"So will you train us to be super powerful heroes and help us get our Cutie Marks!?" bounced Scootaloo excitedly.

Saitama paused, pondering for a moment as she tapped her chin with a hoof. Thinking over the offer for a moment, "Uh…alright, I guess. I suppose I needed a new student since Genos is currently…unavailable…." Saitama stiffened her posture as she snapped up on her back hooves and took a fighting stance, "If you want to learn the One Punch, it will take dedication; you will train every day with a hundred sit-ups, push-ups, and squats! With a ten-kilometer run!"

The girls looked at each other with puzzled expressions, "Er…no offense but isn't that…." Apple Bloom fumbled with her words.

"That's just basic endurance training!" Scootaloo whined, "If you're not going to help us, just say so! But don't waste our-"

Sweetie Belle quickly smacked Scootaloo's mouth shut, "Maybe this is just a test Scootaloo shush! Obviously, she's just saying those things to see if we're worthy of such awesome power!"

Saitama nervously chuckled before stiffening her brow, "Y-yeah! If you want to be my students, you gotta be disciplined!....Yeah….”

"There's really nothing else to it. I don't know what they're going to do when they finally figure out that the endurance training is all I have to show them." Saitama thought to herself.

As of now, I just work at the orange girls' apple orchard. Sugar Cube Corner…or something. It's alright…but now her sister and her weird friends keep harassing me about helping them find a Cutie Mark?... What exactly did I do to deserve this again? And why can't they make me a boy horse!?