My Oath Academia

Fate/Kaleid: Oath Under Snow x My Hero Academia crossover

Chapter 1: One Oath Fulfilled

"Brother."

Deep under ground two siblings, not of blood but of choice met again for the first time in nearly a year. One, a young man with rust-red hair except for a small section of white above his left amber-gold eye who was tall for his age and with the physique of a serious athlete, who was wearing a long black coat over a long sleeved white and blue shirt and a pair of blue jeans over white and black sneakers. The other a young girl on the cusp of reaching the first decade of her life with amber-gold eyes identical to her brother's and black shoulder length hair that matched the thin black dress that covered her modesty.

"Why are you here big brother? You told me yourself that you and Kiritsugu only saved me to use my power. That I was just your tool."

The young girl's question came out as closer to a harsh choking whisper than a question and one could clearly see the myriad of shifting emotions that swam through the younger sibling's eyes. The brother's from seeing his little again for the first time since she was abducted but also that her first words to him such time apart were so pained, and the sisters at seeing her beloved brother again after her last sight of him was him horribly injured but also knowing what she now knew about Emiya Kiritsugu and Emiya Shirou.

"I'll finish what I was saying back then, Miyu, but couldn't." Emiya Shirou's voice was calm, but a little hoarse from holding back tears at the sight of his little sister looking so innocent but tortured and vulnerable. "It goes without saying, I'm your older brother and older brothers protect their little sisters."

As if to punctuate his point the red-head withdrew a stack of seven large cards that floated up from his hand to circle high around Miyu's prone body.

"I've made a lot of mistakes up to this point and this too might be a mistake, but this alone is true." Shirou knelt down next to his sister and met her shimmering orbs with his own resolute eyes, one pair of orbs shinning with emotion and the other near lifeless but still caring. "I wish upon the Holy Grail; I pray you find a world where you won't have to suffer any longer. I pray that you meet kind people. I pray that you find friends you can laugh with. I pray you find… a warm, small…"

Suddenly a series of beautiful blue, magical light lines sprung to life at the four cardinal directions around the two of them. The lines stretched into the air before splitting apart in hundreds of different directions until they formed majestic trees of light.

"Share of Happiness."

With a whirl of magical energy and a serious rumble of the granite walls around them a giant magic circle sprung to life above the siblings, with the seven floating and glowing cards flying higher to take their places in the giant magic ritual as to direct the flow of the massive amounts of mana within. With the circle finished Emiya Miyu slowly floated off her alter-like resting place and into the middle of the magic circle, all the while her brother held her delicate hand with all his callous digits until her lack of gravity pulled her away from him and her eyes closed in exhaustion.

"Bro…ther." Her voice was nary a whisper and difficult to hear, even in a silent cavernous cave.

After his gaze locked on her departing form one last time, Shirou turned away from her so he could face the new arrival to the Holy Grail camber, only this time his march to war was less of one of a man on a mission, but one of a man about to face the executer's axe with their head held high.

"Good bye Miyu, I love you."

While he said the words to himself, if Emiya Shirou had looked at his adopted sister one last time he would have seen his sister's identical eyes open one more time and tears of joy, of sadness, or worry, of fear, and of love falling to the chamber's stone floors.

"I'm sorry but my sister is working her hardest at the moment," The red-head addressed the scantily-clad blonde woman that had entered the chamber in naught but a white and red bikini top, one golden gauntleted arm, a golden armored red skirt, and a crown-like ornament in her golden hair. "So, I'm going to keep you company until she is well and truly on her way to a happier life."

"Your wish will not come true." Angelica Ainsworth's voice was cold, articulate, and full of an icy hatred. "You who entered this Holy Grail War on a fluke and with a worthless, fake class card should never have even reached this chamber dedicated to saving mankind's existence. And now that you don't even have your fake class card you, being nothing more than a regular failure of a magus, standing against the power of the greatest of Heroic Spirits would be utter foolishness."

As Emiya Miyu looked down on her beloved brother, she witnessed him being blown backwards as the most powerful of her captors launched a wave of brilliant metallic weapons at him. She watched as he rose back to his feet despite the blow being strong enough to slay any normal human, and she watched as he activated his magic circuits and allowed a Counter Guardian turned Heroic Spirit to invade his already weary body and filled him with power, skill, technique, and steel enough to stand his own against the greatest of Heroic Spirits.

She saw how his soul was slowly being destroyed to accommodate a power that should have been beyond him and saw how he did it all for her and her happiness.

"Humanity huh…" Shirou showed a pained smiled slightly as he stared Angelica Ainsworth in her hate-filled eyes. "That's pretty big. More than just words, it's an enormous weight on your guys backs. But you know… I'm also shouldering something, and I think it is just as important as your goal."

She saw how he judged her more important than even the world they lived in and a despairing sob escaped from her lips.

"Big brother…" Her words could be heard by neither of the warriors fighting below her nor any living being in the world, but one entity listened to her words, her will, and most of all her wishes above all else. After all it was still 11:50 pm on July 29th and she was still only nine; her veins still pumped the blood of the Child of God and held a unique power in this world. "I… I… I couldn't live a happy life without you in it! I wish you would come with me!"

And as the miracle machine known as the Holy Grail gathered magical energy it recognized the you girl's most heart-felt wish and the power her blood contributed to the mystical machinations and altered its parameters of success.

To fulfill the wish made upon it with the self-actualization of its ritual, the system would need to transport Miyu Emiya to a new world with Shirou Emiya, one that she could live happily in.

As the mystic machine charged and ran calculation after calculation Shirou Emiya, with his body constantly being invaded and possessed by Counter Guardian EMIYA, fought Angelica Ainsworth to the very limit of his human body's abilities and then beyond by summoning forth an impossible Reality Marble that was the inconceivable fusion between his own inner world and that of the powerful spirit that was constantly invading his body.

A black, moonless sky hanging high over a wasteland of snow and ice, and a constant blizzard making perfect vision near impossible. Sunk into the snowy wastes were a numberless amount of swords, knives, spears, axes, hammers, of weapons of varying quality, majesty, and brilliance. The only exception to both the snow and weapons was the top of the tallest hill in this man-made world, where instead of weapons or snow was a small peak of the greenest, healthiest grass surrounding a field of beautiful delicate flowers.

As the two warriors waged a war of flying, wondrous weapons within the impossible world, the great Holy Grail completed accumulating enough power to perform a miracle. As the two warriors unleashed chaos within the impossible world by unleashing swords of unthinkable size against each other, the miracle creating Holy Grail finished searching countless worlds and calculating the odds of success for each world. As the golden warrior reached her arm into her borrowed Noble Phantasm to draw an alien weapon that wasn't a sword but was, the wish granting Holy Grail locked the temporal-coordinates into its mystic processes and began its final countdown to transition. As the last hope of the Ainsworth summoned forth the power to split Heaven and Earth, the last hope for humanity on this world that was the Holy Grail tagged both Emiya siblings to receive the fruits of this wish. And as a world's worth of swords fought and slowly failed against the winds of destruction, the Holy Grail finished its final adjustments and teleported both protective older brother and caring younger sister to a world where they could find some, small share of happiness.

Emiya Shirou disappeared just as the destructive force of Enuma Elish was just about to slam into his exhausted body, leaving nothing but the dregs of Unlimited Blade Works to fall under the might of Ea. Emiya Miyu disappeared from her place in the center of the Holy Grail's miracle circle, leaving naught but motes of kaleidoscope colored light and even taking with her the seven cards that had facilitated her and her brother's wish.

As for Angelica Ainsworth, she could do nothing but ground her teeth in anger and despair at the departure of her master's last chance to save their dying world.

Upon a near spotless beach on the outskirts of the city of Musutafu, Japan a pair of gold-amber colored eyes opened in time to witness the breathtaking sight of the majestic sun glowing orange over the horizon as it slowly rose from the sea. For Emiya Miyu, a young girl who had never even seen the ocean before, she thought it was perhaps one of the most beautiful things she had ever witnessed. Then as she turned her head to look at the sound of faint breathing next to her the breathtaking view was all but forgotten as she beheld something she cherished above all else.

Sprawled upon the coarse sand barely a foot away from where she laid, Miyu's eyes watered as she took in the sight of her beloved big brother. As she crawled her way to his prone form and lifted his head to lay upon her lap she noticed that he hadn't escaped his clash with the most powerful Ainsworth unscathed; the skin around his left eye and down his neck, on his right forearm and hand, and in strips on his left arm had been turned a darker shade of tan, whether it was from an injury or the consequences of having his body invaded by a Heroic Spirit to fight she did not know. He was bleeding from many small cuts all around his body, enough so that Miyu already felt small amounts of her brother's blood trickle off her lap and stain her dress and hands. And his body temperature was far hotter than normal, no doubt a result from his magic circuits channeling the power of Counter guardian EMIYA and powering a real Reality Marble for five minutes.

"AHHHHHHHHHHHHHHHHHHHHHAAAGGGGGHHHAAAAAAAAAAAAAAAAAAAAAA!"

The sudden sound of a boy screaming at the top of his lungs Miyu can't help but flinch and clutch her brother's head closer to herself as she looks for the source of the yelling. Her amber eyes flicked slightly upwards just in time to witness a boy with curly green hair and a body almost as toned as her brother's finish his victory cry while another voice, this one speaking first in Japanese and then in accented English slowly rises as well.

"Hey, hey, hey. Oh my… oh my… GOODNESS!"

Miyu watched in trepidation as the green-haired boy who looked only a few years older than her but younger than her brother lost the strength to continue standing after his cry and fell from his place on top of the trash heap, but was thankfully caught before he hit the ground by the biggest and most muscular man the young girl had ever scene. Turning away from the odd duo, Miyu focused again on her beloved brother.

"Big Brother, I'm so happy that you're here." Her eyes watered as she bent and pressed her forehead against the unconscious teen's. "I just hope and wish that we can fit in here."

Then Shirou groaned and Miyu cried out as spurts of pain flooded through their bodies.

The time was 6:00 am on February 20th in Musutafu, Japan, but in a different dimension with a dying version of Earth it was 11:58 pm on July 29th and two minuets still remained until The Child of God's blood lost its ability to grant wishes. The day before youths hopeful to attend the hero course of U.A. High School would take the entrance exam that would determine whether they were capable enough to attend the prestigious school. It was the date that Midoriya Izuku finished his training regiment given to him by his favorite hero All Might so that his body could at least withstand the power of the older heroes' quirk. It was the date that two dimension travelers found a new world that they could call home and find happiness within. It was still moments before Emiya Miyu's tenth birthday, and it would be the last day she made a wish as the Child of God, yet in a way that wasn't quite true.

Sorry my fellows, but I'm just fixing a few errors I noticed and/or were pointed out to me in reviews that were in this chapter. So the next chapter isn't up just yet but i'll be working on it after work and homework tonight, so hopefully I'll have it done before the week is over.

Anyway, I am humbled and overjoyed that so many people like this first chapter and want to see this story continue. Miyu-verse Shirou is one of my favorite of the many Iron Magus' in the wide multiverse, tied with the Heaven's Feel Shirou. HF Shirou has my favorite mentality of all the multiverse Shirous, but Miyu-verse Shirou has a similar enough mentality and is, in my opinion, much stronger than his counter-part. So they both tip the scales in different ways.

Have a nice week and you'll hear from me again soon.

Your friendly neighborhood dragon, Glader96.

P.S.: I'm on the last stretch of Assassin's Creed Odyssey and I have absolutely loved it don't be surprised if I take inspiration from some weapons or techniques.

Also I'm looking for a cover image for this story and any suggestions would be appreciated.