Note from the Authors: 

The idea of Demons of Onigashima was due to the fact we always wanted to make a book with Ben 10 in a Ghibli Studio type atmosphere that also showed off our Japanese roots. MisakaLovesYou is from Kyoto which is the Yokai Capital of the world. We just wanted to say we're happy that some of our readers are in fact getting Spirited Away vibes from this side series of Ben and Mikoto's adventures in the realm of demons and japanese gods, as this was exactly our intention. In future books of the Omnitrix Onigashima story-line we hope to implement Impulser, Accelerator, and maybe even Othinus, The Demon Corazon, Vilgax, Aleister and a few other Japanese Fate Servants like Miyamoto Musashi and Sakata Kintoki.  Things are going to get busier now with MisakaLovesYou teaching in Taiwan and our My Alien Academia series coming out with Ben Tennyson joining the spectacular UA academy, but we'll be sure to Plus Ultra our way through all of it!  Thank you to all our readers, and thank you for making Demons of Onigashima a success so far!

Hoshimi stared at the store window before her, the images of the tvs behind them reflected on her rather beautiful eyes.  The images fascinated her. If she asked about it, people might give her some strange explanation related to what Misaka had said about capturing light and reflecting it. 

Hoshimi never learned such things from any of her science tutors. Everything was on how the gods and spirits worked, and how humans in the mortal realm were far less advanced then the superior scholars of the realm of Yokai. 

However that was far from the truth many regards. For one thing, Hoshimi discovered that trains like the Spirit Train that ran between Onigashima and the realm of the mortal humans, were in fact a human invention that was spruced up by yokai with magic to create the Spirit Railways. 

And things like the Internet, never had Hoshimi seen such a strange and powerful chaotic network.  If only the court mages of the Yokai had such a thing, they wouldn't have to bother with such stamina draining communication magic. 

And the ability to capture music in the flat box that Hoshimi had on her now.. it was a wonder she had been holding with her for the long 3 years of her exile. 

Hoshimi shivered, the unusual cold weather of the season was in full affect.. and she didn't know why it froze so much during the summer this year.. 

She moved down the street to a trashcan which was burning while a few homeless people put their hands up to warm themselves.

At that moment a hooded figure walked up behind her. He was short. in fact the figure barely came up to her shoulder, and there was something strange in the gait of which he walked. 

He wore a large red parka and hood that obscured his face. 

"Hey,kiddo, care to make some room? I'm freezing."

Hoshimi nodded and stood aside, allowing the figure to start warming himself.  "Apologies."

"Say, kiddo. " said the figure. "You look a little starved. Want some food? I've got some free sandwich samples over by my box, just got em. Clean, free, thought I'd share some with the other guys here but they've eaten already."

Hoshimi blinked with surprise. "You would share your bounty with me?"

"Sure, you remind me of my sister, I'd totally help you out."  said the figure gesturing for Hoshimi to follow. "Can't leave a kid to suffer the cold without a little food in her belly."

Hoshimi followed the figure over to a secluded alleyway, when suddenly the figure pulled off his parka.

Hoshimi froze and let out a short scream. The figure had a rat-like face covered in fur with yellow bulbous eyes, a bald skinless tail, and what looked like a sharp mane of spines going down from his head to his back. 

"Oh I'm sorry." said the rodent man with a smirk as his spines suddenly raised themselves like a porcupine preparing to strike. "I get it, you ladies like the human ones better.."

Suddenly Hoshimi let out a small moan as she felt a few spines shoot out and stab into her.

There was no pain, just a numbing sensation as she fell over, her body now completely paralyzed.

The monster laughed as he began rummaging through Hoshimi's jacket, pulling out a wallet with a bit of yen and other personal effects like her i-pod.

"Jeez, this all you got?!" muttered the creature with frown and a roll of his glowing bulbous eyes. "At least have enough on you for a train ride to the nearest Hidden Space Port."

"SHEEEEN!!" suddenly there was a wind gust that slashed near the creature's head, cleaving a concrete wall in half.

"Argit.. causing trouble are we?" said a voice. 

A girl wearing a white winter jacket, a blue scarf and black leggings walked out. Her hair was blonde and tied in a braided bun with a blue ribbon. Hoshimi couldn't remember ever seeing a girl more graceful and beautiful looking, her green eyes sparkling like emeralds.. 

In one of her mitten clad hands.. she seemed to be holding something made of pure wind, at least that's what Hoshimi speculated from her fallen paralyzed position, it looked like something was rippling around in the empty space where the girl's mitten was positioned like it was grasping something. 

"Saber!" Argit said, holding up his hands. "Girl! Buddy! You wouldn't cleave a friend in half would you-?"

"We know the same people, that doesn't make us friends." said the girl coldly.  "This one happens to be a friend of the mutual acquaintances we share. I would advise you leave, before I send my blade down your throat."

Argit blinked and shrugged. "Er.. yeah, whatever you say crazy lady, I'm out."

Argit scurried off like a rat into the shadows as the girl knelt next to Hoshimi. "Relax, do not panic, it seems he used the paralyzing kind instead of the sleeping kind ,you will be up in a few minutes."

"Wh..who are you?" Hoshimi stammered.

"A friend of Ben's." said the girl with a small smile. 

"How did you-?" 

"Know where to find you? You would be surprised at the resources for searching that the Plumbers have." said the girl. "I myself was quite impressed with the array of technology involved in finding one person. Oh, forgive me, I seem to have forgotten my manners. You may call me Saber if you wish."

"Saber, that's an odd name."

"It isn't my true name, think of it as a placeholder until we get to know each other a little better." said Saber. "Come, lying in the street is hardly the place or position in which to talk."

Saber picked Hoshimi up and slung her over one shoulder before suddenly leaping a great distance into the air and landing on the roof of a building.

"Y.. you're strong!" stammered Hoshimi with shock.

"Of course." said Saber simply

"Are all mortals like this now?" Hoshimi mused as Saber leaned her against a railing in a sitting position. 

"Like what?" Saber asked as she sat next to Hoshimi, pulling a few sandwiches out of her small backpack right as Hoshimi's limbs were starting to regain feeling. 

"Ben can morph into a variety of strange and wondrous creatures. Mikoto can summon lightning as if she were a descendant of the Raijin,  Kuroko can disappear and reappear instantly.. and Max, well, he seems to know a lot." 

Saber chuckled. "Ahh, I see. Well to be honest, us.. being Ben and company, are not exactly a normal group of mortals."

"Are you saying you are all exceptional among mortals?" Hoshimi asked. 

"We come from Academy City, where the word 'Exceptional' is considered the motto of the norm." said Saber. "The ability to develop powers is something many humans have, and Academy City helps unlock it. Though, I would say some of us are exceptional even for Academy City."

Saber handed Hoshimi's now shivering and unparalyzed hands a sandwich. "Eat, regain your strength, the others are worried sick, including your attendant the tengu."

Hoshimi frowned at her sandwich feeling both irritated and dejected. "You should've let me be. I left for a reason."

"Indeed." said Saber calmly as she munched on her sandwich. "Most people do."

Hoshimi glared at Saber. "That's all you have to say?"

"I know the reason for which you left." said Saber. "And I understand it to be a logical decision in your eyes. However, you must understand thus. Compared to my knight Ben Tennyson or any of the others you have met in his group, how much combat experience do you have?"

"I-I have been trained!" said Hoshimi furiously. 

"That was not the question." said Saber. 

Hoshimi looked down angrily, she could find no way to counter Saber's simple argument.  

"Hoshimi Kintoki, I understand that you have a specific goal in mind, to free you people, and regain a throne you have lost." said Saber. "And it is an infuriating goal, for at the same time, you do not desire such a throne in the stead of your mother's death. However, the enemy stands more to gain by your death than by the death of my trusted partners. The only logical answer here is that you remain with them. I am sure they have already proved more than capable of fighting demons."

"Wow.. Kintaro really told you everything.. didn't he?" muttered Hoshimi.

"He felt it prudent that all parties involved in the search be notified of what you were dealing with." said Saber gently. "And I can't say that I am too different from you in certain respects. I once ruled a country myself."

"Did you feel prepared?" asked Hoshimi quietly. "To take such a burden.. to rule that country?"

Saber smiled. "No, not a single minute of any hour or day did I feel prepared. I spent my entire childhood training under a knight and then trained by a mage to become the perfect king. Never did I feel I was ready even after all the training had finished. The capacity to be King is a rare gift, and not necessarily a good gift. I would not wish the burden on any. But those who choose to put the burden upon their shoulders in spite of the fears and woes, and do what they can to do what is right for their people over themselves.. those are the people I would hope to rule no matter how poorly they do it."

Saber looked at Hoshimi seriously. "You will make mistakes, people will die in your name, and there will be nothing you can do to prevent it. But that does not make you a bad ruler. Fear of responsibility.. you have it, and it is well earned, but that does not make you weak, it means you are human. Don't avoid that fear, instead conquer it. You are stronger than you know, I have seen eyes like yours a hundred times, you have the heart and capacity of a ruler."

Hoshimi stared at Saber with wonder. Just who was this woman to speak with such clarity, honesty and wisdom when she looked no older than a high schooler?

Suddenly Saber narrowed her eyes. "Hoshimi.. get down quickly!"

 There was a burst of sparks as suddenly an arrow seemed to come out of nowhere, engulfed in flame.. and the invisible thing in Saber's hand deflected it.. 

Saber's scarf billowed in the wind as she let out a deep sigh. "I can sense your presence, there is no point in hiding.."

A figure stepped out of the shadows.. it was a woman.. she looked around 20 in human years.. except it was already pretty obvious she wasn't human. She had cat's ears poking out of her snow white hair, wearing samurai's attire and a kimono, while a cat's tail waved behind her..  actually it was like two tails with how it was forked. 

"Masako?" whispered Hoshimi as the cat woman drew another arrow from the satchel on her waist. 

"Lady Hoshimi, troubling that you have not died immediately, it would've saved us some trouble.." said the woman with a sigh, her yellow cat like eyes glowing in the night.  Woman who hath defended her, I will not ask you to stand aside again."

"Who is she?" Saber asked.

"M.. My old handmaiden, she was my attendant alongside Kintaro!" stammered Hoshimi. "I.. I thought by now Kitsune would have-."

"Killed me? Do not be mistaken. I have allied myself with her for I believe it to be the correct path." said Masako with a sigh. "Rest assured however Hoshimi. I take no pleasure in killing you, it simply must be done."

________________________

Masako No Kaen

Yokai: Nekomata. 

Ability: Nekomata are cats that have grown into humanoid beings eventually after living long enough. Unlike Bakoneko, their close cousins, Nekomata have forked tails and are known to control fire. They have a tendency to be ferocious and unforgiving towards humans and legend says that cats discontented with their owners transform into Nekomata. Nekomata can also transform either into large cat forms, or ferocious bigger versions like lions or tigers.. depending on the Nekomata in question. Their control over flame is only rivaled by one species of alien in particular. 

Other facts: Masako was the handmaiden to Hoshimi, and even raised her to a degree, singing soft songs to her from the time she was born and in the crib. Hoshimi and her mother were probably the only humans Masako ever loved as she was known to despise humans from centuries of abuse by Japanese feudal lords.  She has yet to meet an opponent she can not burn. 

________________

Saber gripped her sword tightly narrowing her eyes. "Oho? So you consider this to be your knightly duty? Then I ask of you, which master do you serve, which master did you swear loyalty to?"

"I swore loyalty to the Kintoki family, however I now serve Lady Kitsune.." said Masako.

"Then you are lacking in any honor, a knight does not break their oath of fealty on the basis of differing ideals. " Saber said, her eyes narrowing in anger. "Have you no pride?"

"I am no knight.. I am a samurai." said Masako.

"Then do Samurai have any pride of their own either..?" Saber asked.

"Masako.." Hoshimi felt her heart sink into impossible depths. She had missed Masako almost more than anybody else back at the castle. "Why? I... I..."

Tears began to well up in her eyes. "This can't be true.. this can't be, it's impossible. You're acting right?" Hoshimi began to laugh as she struggled to hold back her tears. "R.. right you're joking! It's all one big j-joke.. it's one big.."

"Princess.." whispered Masako as suddenly the tips of her forked tail ignited into flames and she shouldered her bow, drawing a katana that burned with blue flames. "You of all people should know.."

Masako's eyes flared with cold merciless killing intent as a shadow crossed her face. "I never joke about killing my prey."

There was a flash of flame as Masako moved at impossible speeds, and suddenly Hoshimi fell back, yelping as a burst of sparks and a shockwave erupted from Saber's invisible blade connecting with the flaming sword. 

Masako's cat-like eyes widened. "Your speed is well honed for a mortal. 

Saber's eyes flashed fiercely. "A knight cannot turn away from a person in need,  not when you've made a mockery of your oath and forced tears upon the one who depended on you. I will take your head."

Hoshimi fell to her knees, tears splashing down her face. "You.. you... Masako.. you.."

 years ago..

A little Hoshimi laughed as she ran through the streets of what appeared to be an edo style town. Houses made of wood, slender curved roofs, streets filled with various yokai and humans pulling carts or conversing in Japanese..  it was fun to see the sights outside the palace.. 

"M'Lady!!" Masako, dressed in a white kimono and red samurai armor ran after the girl worriedly. "You musn't be running off like this. I promised your mother I'd bring you home safely and-.."

Hoshimi didn't remember when during the chase she actually managed to lose Masako, but she felt a strange feeling the moment she realized that Masako's voice was no longer resounding nearby.. 

"Onee-san..?" Hoshimi said stopping in her tracks, looking around. She was in an alleyway and looming over her, was a large Kappa with an angry disposition in it's eye.

"Oi.." said the kappa reaching out a webbed hand. "You're that princess eh? Because of those stupid taxes the Empress has been levying I've had to close my shop.. you happy bitch!? You happy about what your stupid mother's done!?"

"W.. wha!?" Hoshimi had never experienced such aggression before. Usually her citizens treated her with gifts and pastries, this was far more than the 5 year old girl had ever known.

"C'MERE BITCH!" roared the kappa slamming Hoshimi to the ground with one hand as she tasted blood. 

"H.. HELLP!!" Hoshimi screamed. "SOMEBODY!!"

"SHEEEN" before she knew it, Hoshimi was on the ground with a bruise on her face while next to her, was a bloodied headless kappa.

The warm arms of Masako picked her up and hugged her close. 

"Thank goodness." Masako said tearfully. "Don't worry I'm here.. I'm here, don't cry sweetie.. don't cry."

Hoshimi stared at the present day Masako with horror, despair and shock. "Why.. why? Tell me please.. "

Masako sighed. "Perhaps, it was because you are human."

"Because.. I am.."

"I loved you as my own, however,.. however Lady Kitsune always reminded me of the truth. That truth being humans while beautiful as children will always eventually grow to become selfish fools. Selfish fools who abuse cats, cut off their claws and send them from their homes to starve, like my first master before I became a Yokai and gained human-like form.. human-like form I so detest."

"Th.. they called you the most beautiful Yokai woman in the land.." stammered Hoshimi.

"Beautiful in the eyes of humans you mean.. " Masako growled "Do not patronize me former princess.  I will not be cared for, or made to feel attachment to a human. I should never have loved you or your mother.. being ruled by a human is the ultimate embarrassment for a yokai or cat..  I disgust myself for my lapse of judgement. Your mother's rule.. your time as a princess..."

Masako glared at Hoshimi without an ounce of compassion in her eyes. "It was the biggest mistake in the history of Onigashima. You aren't fit to rule. Give up."

Hoshimi fell cold, her eyes dim. "I.. I.."

"Shut up." Saber said softly.

"Hmm? You speak now human?" said Masako. 

"I said... SHUT.. UP!" growled Saber furiously as suddenly wind surged around her and she hurled herself into Masako with the force of a furious hurricane. 

Masako's eyes turned cold and merciless once more as she slashed her blade at almighty speeds, spirals of pure hot fire trailing from her swings and blasting around her like a furnace, colliding with the gale force winds around Saber. 

The two fighters moved at such speeds that it was a blur as sparks radiated off their attacks colliding. 

Saber and Masako both leaped back from each other panting.

"How are you able to keep up with me!?" snapped Masako. "Humans are inferior, they have not such strength!"

"Truly?" Saber said. "Even before I became a Servant I could have sworn I've fought faster swordsmen. However, I cannot deny your skill makes up for that. You are a gifted swordswoman. A pity that someone so gifted acted so twisted to an innocent girl."

"Oh how chivalrous." growled Masako as flames exploded around her.  "FURNACE OF THE LION!!!"

Masako stabbed her blade into the ground before her, and Saber stepped back, amazed as all the mostly empty nighttime streets filled with giant walls of towering flames.. reaching up to 400 feet high, blasting into the sky..  the entire building was surrounded by a powerful all consuming flame that was even making it hard for Saber to breathe. 

"Gah.." Saber felt sweat pouring down her body in droves. For heat like this to be able to affect a Servant, this woman wasn't just a run of the mill warrior, she was powerful. 

The two of them leaped apart, Saber landing on a different rooftop as Masako did so on another rooftop. 

"She smells of magic." Masako murmured.  "Tch, how much has the world changed in the absence of Yokai and gods?"

Masako raised her blade. "In any case, my mission is not to dance with that woman.. it is to kill Hoshimi Kintoki.

Masako 's palm glowed with a terrible powerful burning sphere of pure heat.

"Fire fortress.. an autumn's full death.. light upon the burning river, this cat's eyes never miss it's mark.. Burn alive.. Amaterasu's Fire!!"

The sphere fired down at Hoshimi with such speed and heat, that even Saber couldn't react in time, merely watch in horror as the flame approached Hoshimi. 

"COWARD!" screamed Saber. 

 Hoshimi watched as the world seemed to slow down around her..  it was strange to watch her life flash before her eyes. All the memories of her long life until this moment, it was quite odd indeed. 

Hoshimi bowed her head. Her tears had evaporated from the approaching heat. Masako was right. She wasn't a fit ruler anyways, she had no power, no means to fight... she had nothing.. 

"This end is a merciful one for someone so useless." whispered Hoshimi as the air around her ignited and she closed her eyes, preparing for death. 

"ULTIMATE SWAMPFIRE!!!!!"

https://youtu.be/5AfTGOdeDDg

There was an explosion as massive tree roots exploded from the earth... roots adorned with glowing blue flowers the size of houses that sparked with blue cinders.. blocking the powerful flames sent by Masako in an instant.

"WHAT!?" Masako said. "My technique burns through all metal and armor.. pierces through even the sacred relics of my people, and it is rejected, by... PLANTS!? What is this devilry!?"

Hoshimi opened her eyes.

She was being held in two massive arms made out of twisted bark, with glowing blue ignited fingers...  The tree being that held her resembled something familiar. Hoshimi remembered it. 

She had seen it once on a passing poster labeled "Meet Ben 10 at the Academy City Cultural Festival." 

She didn't know what Ben 10 was back then, but it was a memorable picture of such an odd creature. 

Ultimate Swampfire.. but.. this looked different. The first Ultimate Swampfire had an appearance of a tree with gel bombs stuck to it's back, but this one, this one's body at the top had morphed into petals made of bark and encompassed something beautiful.. red glowing gel-like flower-petal thorns shaping themselves into a beautiful flower, glowing with immense white heat. 

___________________

True Ultimate Swampfire (Full Bloom). 

Alien

Species: Evolved Methanosian after Blooming has taken place. 

Power: Upon awakening the full potential of the Ultimatrix Innitiative, Ultimate Swampfire now includes the Blooming that it's original form underwent in the theoretical evolutionary form.  Its fire is now multiple times hotter, and able to be projected with greater force. Glowing spores fill the air, flying out of the flower that is it's body, highly explosive, and resembling glitter, allowing it to turn the entire environment around it into a display of explosive beauty.  Flowers resembling his body bloom upon the roots that it raises from the earth, allowing him to project more flames from them, giving him greater versatility and range in combat.  Along with his usual control over plant life and Gel Bombs, Ultimate Swampfire has regained the regeneration ability of it's original self. He can also grow parts of his body like a plant, altering the shape and size of parts of his body. 

(The image on the right is God Swampfire's bloomed form)

___________________

"It's.. beautiful.." whispered Hoshimi. "Like.. blue sakura trees in full bloom.."

Ultimate Swampfire's green eyes blazed with heat as sparkling glittering glowing blue spores filled the air around him like stars dancing in the night air. "Don't you dare.." 

"Wh.. wha?" Hoshimi stammered.

"DON'T YOU DARE ACCEPT DEATH!!" Ultimate Swampfire roared furiously. "DON'T YOU DARE ACCEPT IT SO EASILY.. NOT WHEN THERE ARE THOSE THAT CARE ABOUT YOU! HOSHIMI!!"

"B.. Ben?" whispered Hoshimi. 

"He made it.." Saber said, sighing with relief. "What took you!?"

"Traffic!?" said Ultimate Swampfire.  "I don't know.. the weather's turning more abnormally cold by the day, the roads have been icing over, causing unbelievable traffic jams, I literally flew here after some frustrating turns. Mikoto and the others are on the way. Anything I should know here!?"

"That is apparently Hoshimi's former attendant and one who raised her." said Saber. 

"Wait.. and she's trying to KILL Hoshimi!?" Ultimate Swampfire growled. 

"You should have let me..." whispered Hoshimi. 

"Eh?" Ultimate Swampfire blinked. 

"Why... didn't you let a piece of trash like me just die!?" screamed Hoshimi tearfully. "NOW SHE'S GOING TO KILL YOU TOO!!"

Ben felt something throb in his heart as he looked into Hoshimi's eyes. And suddenly he found himself looking at a 12 year old Ben kneeling in front of a burning house.. Vilgax's blood in his hands as he screamed into the air, believing himself worthless, a burden that was better off dead.

He was looking at himself. 

Ultimate Swampfire's eyes dimmed. "Because believe it or not, your life is worth something to somebody."

"You'll grow to hate me too, you'll grow to hate me, like all the others." sobbed Hoshimi. "Just, get out of here Ben, run. Live your life, don't let me destroy another person by being here.."

Ultimate Swampfire's eyes flared as blue flames blazed from them. "No."

"DAMN IT BEN!! LEAVE, LET GO!!!" roared Hoshimi. "JUST.. LEAVE!!"

"Do as she says." said Masako. "You must have seen it by now. She is a cursed child. All mortals who run with demons eventually meet a foul end.  Not that it isn't deserved. "

"And what kind of person are you who thinks you get to decide THAT!?" Ultimate Swampfire roared. "You were trusted by her.. YOU'RE the one who made her like this, don't try and saddle the blame on humans! I've had enough of that crap from aliens!"

"Who am I?" growled Masako, scowling deeply.

Flames of unbelievable magnitude and heat exploded around Masako and immediately multiple sky scrapers around her burst and melted.. concrete turned into molten lava as the earth shook. "I have lived over 100,000 years as the Keeper of the Flame Knights of Onigashima! I am the flame demon of Kyoto, the former Demon Capital, Masako No Kyoto is my name..  and I am the Hero of Yokai!"

There was a silence.

"Do my titles frighten you human?" Masako said. 

Saber stepped back.

"Oh.. wish to escape my wrath swordswoman?" Masako asked.

"No, I just do not wish to stand in his way." said Saber serenely. "You've pissed him off with that kind of talk.. "

"What?" muttered Masako.

"You dare.." Ultimate Swampfire's eyes exploded with blue fire as he set Hoshimi down next to him. "To  try to kill the person you swore to protect..  and you call yourself.. a HERO?  A Hero... A HERO!?"

https://youtu.be/K_xTet06SUo

Ultimate Swampfire let out a roar of rage, and immediately all the sparkling spores in the air around him exploded with volatile force.. turning the very sky blue with immense heated light, the earth trembling. 

"This heat.. it matches my own!?" stammered Masako in shock as she raised a hand to block the surge of hurricane winds blasting at her from the force of the explosions. 

"A HERO PROTECTS THE INNOCENT!! A HERO DOESN'T STEP ON THE LIVES OF OTHERS JUST BECAUSE THEY THINK THEY ARE RIGHT!!" Ultimate Swampfire roared, his eyes exploding with blue fire. "Don't you dare wear that title like a crown, when you've clearly SPAT ON IT!!!"

Ultimate Swampfire propelled himself into the air at immense superhuman speed, launching himself at Masako as a shockwave erupted from the point where he had leaped. 

"GIANT SLAYER'S FIRE!!" Masako roared, slashing her sword upwards, the dark magic spell taking the form of immensely hot flames that carved through the atmosphere itself as it delivered it's horrifying force at the alien. 

"RAAAAAAAAAAAAHHHHHH!!" Ultimate Swampfire pulled his arm back, and immediately roots began twisting around it, growing larger and larger, more and more blue glowing gel flowers sprouting and blooming as his arm grew to massive size. 

"H.. His body, he can grow parts of them like a plant!?" Masako growled. 

Ultimate Swampfire's hand was now the size of a building as blue flames enveloped the fist and he delivered a ginormous punch at the flames that could have wiped out an entire army in a single blast. 

An explosion shook the air as Ultimate Swampfire's  roots which had obliterated themselves in the force of the collision of two attacks fell away from a now normal sized arm. 

Ultimate Swampfire emerged from the clouds of ash in the air, firing a powerful explosive blue flame beam down at Masako from above

Masako's  eyes blazed orange as her tails ignited. She screamed in fury, cleaving her mighty slender blame through the giant blue beam, causing it to split apart around her. 

"That sword's powerful.. but flames from Ultimate Swampfire's true form surpasses Dragon Fire." Saber muttered. "To be able to dismantle such heat, could that sword be a Divine Construct? I underestimated her, she's truly a dangerous opponent. But in this enraged state, I would merely hinder Ben if I tried to assist."

Ultimate Swampfire grew his arm massive again, trying to land another explosive flaming punch straight into Masako

"GOD SLASH.. HELL!" Masako's eyes flashed like the demon she was as there were a few flaming ribbons from her blade moving so fast that they were invisible to all but the truest masters of the blade. 

Ultimate Swampfire's arm was obliterated in an instant, slashed into pieces so small it was like they had turned into dust. 

Ultimate Swampfire's eyes narrowed as he struggled to maintain his combat momentum. He had heard of people like this. Ushi had once described it as masters who had grown so skilled with their blades that they reached the realm of gods on sheer skill alone. Masters like these could've saved the world from Vilgax ten thousand times over just by swinging their blades once. They could even cut the metaphysical with the pure sharpness of their slashes.  Basically skill so absurd that it did the absurd. 

"You are crippled now." Masako growled as she stopped behind Ultimate Swampfire.

But in an instant, bark-like vines whipped out of Ultimate Swampfire's side, his arm reforming faster than even a second. 

"WHAT!?" Masako exclaimed right before Ultimate Swampfire's body emitted a cloud of explosive sparkling spores all over the rooftop. 

"TAKE THIS!!!!!" 

"KAAAAAAABOOOOOMMMMMMMMMMM!!" A tower of pure blue flames shot into the sky, blasting the clouds apart. 

The flames were immediately sliced to bits as Masako shot out of the dust, parts of her armor burnt as she gasped hard. 

"A walking plant, able to heal it's injuries, and emits flames that can match the most powerful Yokai, just what is this creature!?" spat Masako. 

Ultimate Swampfire leaped down from the building and landed in the street slamming his hands into the asphalt, his fingers growing and shooting into the soil hidden beneath the structures underneath. 

Immediately giant tree roots thick as buildings exploded from the street like a tidal wave, chasing after Masako as she leaped from building to building. 

The roots caught up with her and surrounded her.. blue flowers growing all over the tree limbs and sparkling with glittering spores as flames charged up in their centers.

"From the flowers?!" said Masako right as all the flowers erupted with geysers of pure powerful fire. 

"God Slash, fifth form, ULTIMATE KARMA!" Masako's eyes flashed as her flaming blade whirled around her.. and she managed to slice the powerful obliterating flames into nothing.

Ultimate Swampfire came down from above as the roots parted for him.. 

"Above? No.. he has experience as a fighter that much is true, this is too direct for somebody of his experience.." said Masako as she landed in the street. 

Suddenly Masako noticed that the air was filled not just with spores.. but with..

"Flower petals?" whispered Masako as blue petals filled the air like a large cloud. "I can sense power in each petal.. as if they've drunken in explosive heat, th.. this is.." 

"The technique Impulser and Mikoto helped me perfect as God Swampfire..." Ultimate Swampfire growled. "It's not nearly as effective in Ultimate form.. but.. thanks to my spores in my blooming form, I can make a rough recreation of it by letting the spores drink the explosive nectar into the veins of the petals..  get ready.. for my finisher!!!"

Ultimate Swampfire's eyes ignited with powerful blue flames that immediately turned white. " SENBONZAKURA, ONE THOUSAND PETALS OF FLAME!!"

The petals all exploded at once, turning into white fire that grew into a massive explosion that was so bright it was as if the sun came out early, turning the area into temporary daylight. 

Hoshimi covered her eyes, her mouth open. "Th.. this is wait.."

Hoshimi felt terror course through her as she saw the air around the powerful giant white fireball turn gray. "NO BEN!! GET OUT OF THERE!!!"

"Memento.. Stop.."

Everything turned gray suddenly, everything froze, the air, the fire, everything, even sound.. then suddenly, the flames imploded back into the flowers.. the roots disappeared, the heat stopped and Ben suddenly found himself standing in the street back in human form. 

"Wh.. wha?" Ben stammered

Masako was panting hard, standing in front of Ben, her armor partially charred, her eyes wide in shock, fear and anger. 

"My greatest technique, it can only be used 2 times a day.." said Masako with a glare. "Memento.. my skill with the blade reached such height, that at it's zenith, I found myself capable of cutting through time itself.  However using such a technique exacts a toll on my body, I won't be able to use it again without falling unconscious.. With it, I am able to slash apart events in time, sewing together what's left into a new timeline."

Ben's eyes went wide. It took a little thinking but it was a terrifying power once you made sense of it.  Basically the technique treated Time like a patchwork quilt. Say you sewed in pictures into the quilt. Picture of Ben in human form, tapping the omnitrix, picture of him transforming into Swampfire, picture of him transforming into Ultimate Swampfire, picture of him going onto the roof, so on and so forth.. but then you took some scissors and cut out the middle parts which had him transforming and then sewed the remaining parts back together to close up the hole so you only had human Ben and the street before he went on the building. 

Basically, Masako had just cut out entire key events out of the environment, and somehow managed to do so without disrupting the rest of the fabric of time.  She cut through the process that Ben had undergone to transform and therefore he never went Ultimate Swampfire canonically, and the flames never happened. 

"Jeez.." Ben said, his eyes wide. 

"You are a human? I never would have expected such a strange mortal creature to have the true form of a human being." growled Masako as she drew her blade. "But no matter.. I'll kill you, as soon as I fulfill my true objective."

Masako sent a blazing shockwave from her sword, aimed at something.. right past Ben's shoulder,  HOSHIMI!?

Hoshimi was standing in the street, confused as to where she was... did Masako manage to cut out the events leading to Hoshimi being on the roof too!?

Ben moved without thinking..

https://youtu.be/GP6eLe-Uzak

He moved.. while at the same time his hand reached reflexively towards the Omnitrix. He needed to block the attack, turn into Chromastone or NRG, somebody immune to the heat.. someth-.

Ben stopped, time was frozen, but not because of Masako this time.. his brain barely functioned as he stared at the bloody gash across his chest accompanied by burn marks. 

"Eh... Too.. late.." Ben said.

Hoshimi stared with shock. "Wh.. why..? Why did?"

"Ain't it obvious..?" Ben gasped as Masako stared as well, looking bewildered. "I'm the hero around these parts.. not her, and I'm here to save you."

"B.. BEN!" screamed Hoshimi as Ben fell over into her arms. "BEN PLEASE STAY WITH ME!! I... I... "

Hoshimi's tears splashed down her face as she finally expressed her truly selfish desire. "I.. I want you to save me.. PLEASE.. I.. want you to save me!!"

"He.. A human performed... such a selfless.." Masako stammered. "This is impossible, you must be joking, you must be.."

"RRAAAAAAAHHHHHHHHHHHHH!!!" Saber suddenly appeared behind Masako, her blade drawn and revealed, the shining glory of Excalibur now shining bright as she swung her Noble Phantasm at the Nekomata with immense ferocity. 

"URGH!!" Masako blocked the attack as a shockwave erupted from where the blades met. "y.. You haven't shown your true power either!? Are.. are mortals monsters!? You're all crazy, you're all.."

"Face me coward!!" Saber growled angrily, and I'll show you precisely how much of a monster I am!!"

"Tsk.. I've already tarried too long, this mission is failed!" Masako said before leaping back and disappearing in a sudden burst of fire and smoke..

"COME BACK!! Face me!!" Saber roared. 

Saber stopped and shook herself, she needed to deal with the present situation. She looked down at where Ben was lying with his head on the sobbing Hoshimi's lap, just as Kuroko and Mikoto appeared next to her, having teleported repeatedly fast to the scene. 

"Ben!" Mikoto said, her voice filled with horror, running to join Hoshimi. "What happened!?"

"He ran into one of the demons." said Saber. "Will he be alright?"

"He's healed from worse.." said Kuroko, looking a bit panicked herself, but somewhat relieved as she observed the wound. "Without the Omnitrix he'd be toast though.. "

Saber sighed in relief. "Once more you pull through odds I cannot fathom old friend.."

"What about her?" Kuroko asked as she watched Hoshimi sob into Ben's arm while Mikoto gingerly held her with one hand, the other clasping Ben's hand. 

"Let her be.. she's been through enough hell for one day." murmured Saber.