Fate: Emblem Heroes (Fate/Stay Night x Fire Emblem Heroes)

[StrikeMechanic23]

Hello, readers! After re-downloading and playing FSN, I'm inspired enough to create a one-shot crossover fanfic like this, where Shirou's background is very different due to his past life!

This was originally a one-shot crossover fic, but due to enough reader reception on SpaceBattles, I'll have to balance this out carefully due to real-life events, and I'm also busy writing "The Demon-Summoning Samurai of Kivotos".

This is now a multi-chapter fic!

Are you readers ready?

Type-Moon and the Fire Emblem franchises belong to their respective owners.

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Fate: Emblem Heroes

Chapter 1: Prologue – Rebirth by Fire
​

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The world burned.
​

Fuyuki City had become hell incarnate... a writhing apocalypse of flame and shadow that consumed everything in its path. Buildings collapsed like broken toys. The screams of the dying echoed through smoke-choked streets. And in the heart of this inferno, a boy with auburn hair stumbled through the wreckage, his small body battered and broken.

'I'm going to die here.'

The thought came with eerie clarity.

From what he could remember, his current name was…

Shirou.

An eight-year-old boy, orphaned in an instant, couldn't feel his legs anymore. Couldn't remember where he'd been running from. Couldn't recall what his parents' faces looked like.

He collapsed against a pile of rubble, vision swimming. Above him, the night sky glowed an angry crimson, as if the heavens themselves were aflame.

'Is this... the end?'

His right hand twitched.

Something stirred within him… Not pain, not fear, but warmth. A presence both foreign and intimately familiar, like remembering a dream upon waking. His fingers moved of their own accord, reaching toward the smoke-filled air.

Light erupted from his palm.

Shirou gasped as a weapon materialized in his grip—sleek, otherworldly, humming with divine energy. It resembled a gun, yet its design transcended anything that should exist in this burning world. Golden accents traced along white and blue metal. Runes he didn't understand pulsed with soft luminescence.

'Breidablik… The divine relic capable of summoning Heroes from multiple worlds.'

The name came unbidden, rising from the depths of memory that shouldn't exist. His seven-year-old mind reeled as knowledge flooded through him—not learned, but remembered. Images cascaded like a broken dam:

'A castle floating among clouds.'

'Countless Heroes from a hundred different worlds, all answering his call.'

'Battles against fellow mortals, gods, beasts, monsters, and demons.'

'Friendships forged by fire across impossible distances.'

'A world-tree connecting infinite realms.'

'A final confrontation with a being called Rune… or rather, Alfaðör, the Creator himself.'

'And a name...'

'His name is...'

'Kiran.'

"I was… Kiran… the Summoner…" Shirou whispered, his child's voice barely audible over the roar of flames. "I commanded the Order of Heroes. We defeated Alfaðör the Creator. I..."

Shirou stared at the Breidablik, this impossible artifact from a life he'd somehow lived and lost. The divine weapon pulsed in response to his recognition, as if welcoming home a long-absent master.

Rune's final words echoed in his recovered memory:

"This is my blessing to you, Summoner. Reincarnation with memories and power intact. It will serve you well in the next world."

"The next world..." Shirou looked around at the burning hellscape of Fuyuki. "This world."

The weapon felt weightless in his hand despite its impossible nature. Part of him wanted to test it, to call forth the Heroes he remembered commanding. But exhaustion dragged at his consciousness. The Breidablik flickered—responding to his wavering will.

'Not yet,' Shirou thought as some instinct whispered in him. 'The time isn't right.'

With effort born from memories of a lifetime spent mastering this artifact, Shirou dismissed the Breidablik. It dissolved into motes of light, vanishing back into whatever space between worlds it inhabited when not summoned.

His hand fell limp.

The pain returned immediately…

As his burns, his broken ribs, the smoke filled his lungs, Shirou coughed violently, tasting ash and blood. His vision darkened at the edges.

'I survived a war against the Creator of the Nine Realms, only to die in a fire as a child?'

The irony would have been funny if he weren't so tired.

Shirou heard footsteps.

Through the haze of smoke and delirium, Shirou saw a figure approaching.

A man, tall and gaunt, wearing what had once been a business suit, now torn and stained with soot and blood. His face was haggard, his eyes hollow with the weight of some unbearable burden.

The man stopped when he saw Shirou. His eyes widened.

For a long moment, neither moved. The man seemed frozen, staring at the broken child amid the rubble as if he were seeing a ghost. His lips trembled. His hands shook.

Then he ran towards Shirou, a mere boy walking through what seemed to be the fires from the Realm of Hel itself.

Shirou didn't have the strength to react as the man dropped to his knees and pulled him into a desperate embrace. The stranger's body trembled violently, and Shirou felt wetness against his shoulder… tears, hot and uncontrolled.

"You survived," The man choked out, his voice raw with emotion Shirou couldn't identify. Relief? Anguish? Both? "Someone... someone actually survived. I saved... I finally saved someone..."

The words came out broken, fragmented, as if the man couldn't quite believe them himself. His grip tightened—not painfully, but with the desperation of someone clutching the last piece of driftwood in a storm.

Shirou's memories as Kiran stirred. He'd commanded hundreds of Heroes and witnessed countless reunions between warriors separated by death and by dimension. He recognized grief when he saw it. Recognized guilt.

'This man…' Shirou looked at the disheveled man. 'This man has failed to save people before… Many people.'

As the man kept hugging Shirou, this made Shirou gather his strength to ask the stranger a question.

"Who..." Shirou's voice came out as barely a whisper. "Who are you?"

The man pulled back slightly, just enough to look Shirou in the face. His expression was a mask of barely-controlled emotion—joy and sorrow warring for dominance. When he spoke, his voice cracked.

"Kiritsugu," he said. "Kiritsugu Emiya."

'Emiya,' Shirou's fading consciousness, noted. 'Will my last name be the same as…'

"I'm taking you home," Kiritsugu continued, carefully lifting the boy into his arms. "You're going to live. I promise you that."

As Kiritsugu carried him away from the flames, Shirou's consciousness finally began to slip. The last thing he registered before darkness claimed him was the feeling that his life had just been irrevocably changed.

A god had blessed him with reincarnation.

And a broken man had given him a name.
​

---

Ten Years Later
January 31st, 4:00 AM

Shirou Emiya woke with a gasp.

His hand shot out instinctively, fingers grasping empty air before his conscious mind caught up with muscle memory honed across two lifetimes. His heart hammered against his ribs as the dream—no, the memory—faded into wakefulness.

The Fuyuki Fire.

It was always the Fuyuki Fire.

He sat up slowly in his futon, running a hand through sweat-dampened hair. The pre-dawn darkness of his room felt oppressive, shadows clinging to corners like accusatory specters. His breathing gradually steadied as he grounded himself in the present. Shriou looked at a nearby clock, and it was 4:03 am.

'January 31st, approximately 4:00 am. I'm eighteen... A decade after Kiritsugu saved my life…'

The knowledge sat heavily in his gut. Between his recovered memories as Kiran and the research he'd conducted over the past decade, Shirou knew what was coming.

The Holy Grail War…

A battle royale between seven mages and their summoned Servants, all fighting for a wish-granting chalice.

A chalice that, if his suspicions were correct, had been corrupted by the very curse he'd survived as a child.

His right hand twitched, knowing that the Fifth Iteration of the Holy Grail War was on the horizon.

Before he consciously decided to do it, light bloomed in his palm. The Breidablik materialized with familiar weight, its divine presence a stark contrast to the mundane bedroom around him. Even in darkness, the weapon's golden accents seemed to glow with inner radiance.

Shirou stared at it, turning the artifact over in his hands.

"Why?" Shirou whispered to the empty room. "Why do I still have you?"

It was a question he'd asked countless times over the past ten years. According to everything he'd learned about reincarnation in both his lives, items didn't carry over. Memories, perhaps. Soul-bound contracts, maybe. But physical objects—especially divine artifacts of Breidablik's caliber—shouldn't have followed him into this new existence.

Yet here it was.

The weapon responded to his touch as perfectly as it had in his life as Kiran. He'd tested it cautiously over the years, summoning Heroes in secret, dismissing them quickly before anyone could notice. The contracts remained intact. The power remains unchanged.

'Rune's blessing was more thorough than I understood,' Shirou mused, running his thumb over the intricate rune-work. 'Or perhaps…'

He recalled something Veronica had once told him, back at the final battle of Ragnarök:

"The Breidablik is not merely a weapon, Summoner. It is a Fire Emblem… It is a divine artifact that bonds with its chosen wielder. You and it are two halves of a whole."

If that were true… If Shirou himself was somehow part of the Breidablik, then perhaps it hadn't followed him through reincarnation at all. Perhaps it had simply... waited. It lay dormant until its other half awakened to remember what he was.

The implications were staggering.

A Fire Emblem.

Artifacts or entities that define the pinnacle of that world's hope, a final message to those who would stand against good, justice, and the oppressed.

Fire Emblems could assume multiple forms, depending on the world they came from.

Most of the time, they were items or weapons, such as a Sword or a Medallion.

But occasionally, a Fire Emblem might manifest as a sapient being, with the two versions of the same Hero from two versions of the World of Elyos could attest.

Now, for the Breidablik itself…

A divine artifact connected to Yggdrasill, the World-Tree that linked all realms touched by the Fire Emblems. A weapon blessed by Rune Alfaðör himself, the Creator who stood above even the gods.

And somehow, it existed here.

In a world governed by Gaia and Alaya, where the Root dictated reality, and the Throne of Heroes supplied Servants for eternal conflict…

'Two metaphysical systems that shouldn't be able to coexist,' Shirou thought. 'Yet here I am. Shirou Emiya, who is also Kiran. A human boy adopted by Kiritsugu, who is also the Summoner blessed by a god from another cosmology entirely.'

The Breidablik pulsed in his hand as if acknowledging his thoughts.

Shirou dismissed it with practiced ease. The weapon dissolved into light, returning to whatever dimensional space it inhabited when not manifested. The room fell dark again.

He lay back down but knew sleep wouldn't return. Not tonight. Not with the dream—the memory—still fresh in his mind. Not with the weight of knowledge pressing down on him.

'The Fifth Holy Grail War… Kiritsugu never stopped talking about it,' he thought, staring at the ceiling. 'Kiritsugu fought in the Fourth War. It destroyed him during his so-called 'victory', and it turned him into the hollow shell of a man who could barely look at me without seeing his failures.'

His adoptive father had died five years ago, revealing everything he knew to Shirou. Yet, one of the things Kiritsugu didn't pass on to Shirou was learning magic properly, except for Structural Analysis and Reinforcement, citing that other types of magic, or magecraft, were too dangerous, even for Shirou.

Shirou knew that Kiritsugu had his reasons, but he let that side because, to be fair to Kiritsugu, the old man didn't know of his secret – that he had the Breidablik with him.

Instead, Shirou focused on the upcoming, harrowing events that would happen in the next few days.

'Seven Masters. Seven Servants. A corrupted wish-granting device.'

And now, added to that volatile mixture: one reincarnated Summoner with access to an army of Heroes from across infinite worlds.

"The rules are about to change," Shirou murmured to the darkness. "As to how it can change, even I don't know…"

Outside, the first hints of pre-dawn light began touching the horizon. Soon, Fuyuki City would wake to another ordinary day. Students would head to school. Salarymen would catch their trains. Life would continue its mundane rhythm, unaware that forces beyond human comprehension were converging on their city.

As he called upon it again, Shirou looked at his hands and gazed at the very divine artifact that Commander Anna had given to him in his past life as Kiran.

The Fire Emblem of the World of Zenith.

The Breidablik.

As he looked at the Breidablik, Shirou knew it didn't belong here.

It wasn't a sword, at least in its default state…

It wasn't something he'd seen and reproduced.

Yet, it existed within his subconscious, nonetheless, a foreign element that his magic acknowledged as intrinsically his.

'Princess Veronica was right. It's because we're two halves of the same whole,' Shirou thought again. 'The weapon and its wielder. Zenith's Fire Emblem and its chosen.'

He opened his eyes and stood, moving to the window. Fuyuki spread before him in the growing light. It was peaceful, ordinary… and doomed.

"Kiritsugu," Shirou spoke softly to the memory of his father. "You tried to save the world through the Grail and failed. You told me to find my path, to learn from your mistakes."

His hands gripped the Breidablik tightly.

"I don't know if this is the path you wanted for me. But I have power you never dreamed of. Knowledge of threats you never understood. And if that corrupted Grail is what you and I think it is..."

The resolve that had driven Kiran through countless battles, the determination that pushed Shirou to train himself to exhaustion every day, crystallized into certainty.

Shirou raised the Breidablik, briefly shifting it into its Sword, Lance, Axe, and Tome forms before reverting it to its Dire form.

"Then I'm going to do what you couldn't. I'm going to save them. All of my loved ones."

Shirou knew he only had a few days.

A few days until the Holy Grail War began.

A few days to prepare for a conflict that would reshape the fate of Fuyuki City.

And Shirou Emiya… The boy who was also Kiran, the human who wielded a divine summoning artifact, the survivor who remembered two lives…

He would be ready.

He needed to.

In his hands, the Breidablik pulsed with agreement.

The blessing of a god, given to save a world.

The time to fulfill that purpose was coming.

---

End of Chapter
​

 

[MrSplashy]

Interesting, I am gonna watch this thread with anticipation. I wanna see how this goes.

 

[StrikeMechanic23]

Hey there, readers!

After a couple of replies, I decided to continue with this crossover fic, given that a lot of you readers have already subscribed.

I'll somehow balance this with the other crossover fic I'm writing. This might result in Schedule Slips (from one post a week to one post per two weeks, plus real-life stuff), but given this fic's reception, I suppose I'll manage.

Although if any of you are willing to help me out in planning this, I'd appreciate it.

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Shirou dismissed the Breidablik with a thought. The divine artifact dissolved into motes of light, returning to whatever space between dimensions it called home when not manifested.

He rose from his futon, moving through his morning routine with mechanical precision. The bath took longer than usual—he needed the hot water to wash away both the sweat from his nightmare and the lingering unease that always followed those memories.

An hour later, dressed in his Homurahara Academy uniform, Shirou made his way toward the kitchen.

The scent of miso and rice greeted him before he rounded the corner.

"Good morning, Senpai!" Sakura Matou smiled from her position near the counter, already wearing an apron over her own school uniform.

Her purple hair was tied back neatly, and her expression carried that familiar, gentle warmth.

"Morning, Sakura," Shirou replied, moving to wash his hands at the sink. "You're here early again."

"I wanted to help with breakfast before school," she said, her hands already moving to gather ingredients. "What would Senpai like today?"

Shirou considered for a moment. "Tamagoyaki and miso soup sound nice."

"Understood!" Sakura nodded, her smile brightening slightly. "If... if Senpai wants, I can also add omurice to our bento? For lunch?"

"That sounds perfect," Shirou agreed. "I'll help with the prep work."

They fell into an easy rhythm—Sakura handling the eggs for the tamagoyaki while Shirou prepared the dashi stock for the miso soup. The kitchen was filled with the familiar sounds of cooking: the sizzle of egg hitting the pan, the gentle simmer of soup, the soft clink of utensils.

But something felt... off.

The Breidablik—dormant within whatever space it occupied when dismissed—pulsed faintly in his awareness. Not a warning, exactly. More like... recognition. The same way it had responded when he'd encountered corrupted beings such as Fallen Heroes in his past life.

Shirou glanced at Sakura, and he noticed that she was focused on rolling the tamagoyaki with practiced precision, her movements gentle and controlled. Nothing seemed outwardly wrong. And yet...

Sakura's hands trembled slightly, just for a moment.

"Um…" She noticed his gaze and looked up, her smile faltering. "Is... is something wrong, Senpai?"

"No," Shirou said, turning back to the soup. He stirred slowly, keeping his tone casual. "Just making sure the miso doesn't boil too hard."

As Sakura resumed her focus on the tamagoyaki, Shirou knew that the lie came too easily.

"I see..." Sakura relaxed slightly, though her shoulders remained tense. "I'll be more careful with the heat."

Shirou let it slide. For now. But he filed the observation away—the trembling hands, the Breidablik's faint response, and the tension she tried to hide beneath that gentle smile.

'Later,' Shirou told himself. 'I'll figure out what's wrong later.'

The breakfast came together without further incident. Tamagoyaki, perfectly rolled and slightly sweet. Miso soup with tofu and wakame. Two bento boxes packed with omurice, the egg wrapping each portion with golden precision.

By the time they settled in the living room with their meal, the clock showed 5:30 AM.

The shoji door slid open with more force than necessary.

"Fooood..." Taiga Fujimura stumbled into the room, still groggy despite being fully dressed in her usual outfit. Her hair was damp from a recent bath, hanging somewhat limply around her face. "Shirou, I smell breakfast... Please tell me there's breakfast..."

"Good morning, Fuji-nee," Shirou said dryly, already setting out a third portion.

Taiga collapsed at the table with all the grace of a puppet whose strings had been cut. "Morning, Shirou... Coffee... I need coffee..."

Sakura giggled softly, rising to prepare tea. "I'll get it ready, Fujimura-sensei."

"Sakura-chan, you're an angel," Taiga mumbled into her arms. "Unlike this heartless student of mine who makes me wake up at ungodly hours..."

"You're the one who insisted on staying here to 'supervise' me," Shirou pointed out, placing chopsticks beside her bowl. "I didn't ask you to match my schedule."

"Details..." Taiga waved a hand vaguely. "Minor details..."

---

The three of them ate in comfortable silence for a few moments. Taiga's transformation was almost instantaneous—one sip of coffee, and the groggy teacher became her usual energetic self.

"You know what's great?" Taiga grinned, pointing her chopsticks at Shirou. "Not only is it the last day of the month, but it's also Friday! The weekend is almost here!"

"Saturday's still a half-day," Shirou reminded her, taking a bite of tamagoyaki.

"It's still going to be a wonderful day," Sakura added softly, her smile genuine despite the lingering tension Shirou had noticed earlier.

Taiga's expression shifted then, her usual playfulness fading into something more serious. She set down her chopsticks, fingers drumming against the table.

"Speaking of which…" Taiga revealed. "I've been hearing some concerning rumors lately."

"Fuji-nee?" Shirou looked up. "Can you tell us more about those rumors?"

"There's apparently been a gas leak in the neighboring Shinto district," Taiga said, her voice dropping slightly. "Multiple incidents over the past week. People have been found unconscious... in comas, actually."

Shirou's gaze shifted to Sakura, and then to Taiga, who continued on with her explanation.

"The official story is about faulty gas lines, but..." Taiga continued as she shook her head. "Just be careful, okay? Avoid that area if you two can."

As Taiga finished rambling, Sakura looked genuinely confused, her brow furrowing slightly.

"A gas leak?" Sakura mumbled. "That sounds terrible..."

But Shirou's eyes narrowed, just for a fraction of a second.

Sakura noticed. Her breath caught, almost imperceptibly, and her fingers tightened around her chopsticks. Yet, she said nothing.

"Anyway!" Taiga's cheerful demeanor returned as quickly as it had left. She waved her hand dismissively, grabbing another piece of tamagoyaki. "Those are just rumors I heard around the faculty room. Don't take it too seriously, okay? The city officials are probably handling it."

"If... if Fujimura-sensei says so," Sakura said quietly, her eyes downcast.

"Right," Shirou agreed, forcing his tone to remain casual. "It's best not to think too much about rumors, especially when we need to focus on getting ready for school."

The rest of breakfast passed without incident. The earlier tension dissipated beneath mundane conversation—Taiga complaining about her students, Sakura mentioning a test in her class, Shirou confirming their lunch plans.

When the meal ended, Shirou stood and began gathering dishes.

"Don't worry, Sakura," Shirou assured her. "I'll help with the cleanup."

"Thank you, Senpai," Sakura said, rising as well.

Together, they moved to the kitchen sink. Taiga wandered off to finish getting ready, her voice echoing from somewhere deeper in the house as she sang off-key.

The water ran. Dishes clinked softly. And neither Shirou nor Sakura mentioned the moment that had passed between them.

It was not yet the time, it seemed.

---

Fate: Emblem Heroes

Chapter 2: A Typical Fuyuki School Day
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Taiga had already rushed ahead, her bag bouncing against her hip as she called back something about "preparing lesson materials" before disappearing around the corner.

"Fujimura-sensei really is energetic in the mornings," Sakura said softly, helping Shirou secure the gate lock. The metal clicked into place with a satisfying sound.

"When she's had coffee, anyway," Shirou replied, checking the lock twice out of habit. "Before that, she's basically a zombie."

Sakura's quiet laugh was like wind chimes—gentle and fleeting.

They set off together, their pace leisurely. The morning air was crisp, carrying the faint scent of early spring despite winter's lingering chill. Students in similar uniforms passed them in groups, chattering about weekend plans and upcoming exams.

Shirou's attention drifted to Sakura as they walked.

Her sleeves shifted with each step, the fabric of her uniform rising and falling naturally. And there—just for a moment—he saw it.

A dark purple bruise, almost black at the edges. It's circular, like... like fingers had gripped her wrist too tightly.

The Breidablik pulsed faintly within him, indicating something was off, in the same vein as earlier during breakfast.

"Sakura," Shirou said, keeping his voice carefully neutral. "Your wrist..."

Sakura froze mid-step, her hand immediately moving to cover the mark.

"It's…" Sakura stammered. "It's nothing, Senpai."

"Hmm…" Shirou muttered, gazing at her bruise before asking Sakura. "Was it Shinji?"

The question came out sharper than he intended. Shirou knew about Sakura's brother—arrogant, entitled, prone to taking out his frustrations on those weaker than him. If that bastard had...

"No! Nee-san didn't…" Sakura shook her head quickly, her expression almost panicked. "I mean, Shinji didn't…"

Shirou and Sakura briefly stopped walking, and Shirou gazed at Sakura's purple eyes.

"I accidentally stumbled yesterday at home. I caught myself wrong and..." Sakura looked away, her voice dropping to barely a whisper. "Please don't worry about it, Senpai."

The Breidablik's pulse intensified slightly.

The divine artifact was somehow telling Shirou that whatever bruise Sakura had…

It was not just a bruise.

There were faint traces of something else… It was something the divine artifact recognized instinctively.

It was magic… old magic, mixed with the dark magic Shirou had sensed earlier via the Breidablik.

While both magic signatures were separate, both were… off in ways that Shirou couldn't yet understand.

Shirou's jaw tightened, but he forced himself to relax. Pushing now would only make Sakura retreat further. He'd learned that much over the months she'd been coming to help at his house.

Also, the masquerade of the Moonlit World was being applied. Thus, Shirou couldn't afford to act rashly.

In the end, Shirou decided to let this slide for now.

"Just... be more careful, okay?" Shirou said, his tone gentler. "Sakura, if you need anything…"

"I'll be fine, Senpai," Sakura interrupted, her smile returning though it didn't quite reach her eyes. "Thank you for worrying about me."

As much as Shirou noticed that Sakura was trying to assure him, he knew she was lying.

But Shirou let it go for now… for her sake and for the secrecy of the Moonlit World.

They continued walking, the conversation shifting to safer topics—homework assignments, lunch menu speculation, and whether the archery club would practice today, given the weather.

---

When they reached the school grounds, the diverging paths became literal.

"I'll see you after classes, Senpai," Sakura said, bowing slightly.

"Yeah," Shirou replied. "Take care, Sakura."

Sakura headed toward the first-year building, her purple hair catching the morning light as she disappeared into the crowd of students.

Shirou watched her go for a moment longer than necessary.

Then, he turned toward his own building, climbing the stairs to the second-year hallway. Students milled about in clusters, some rushing to finish homework, others gossiping about whatever drama had unfolded yesterday.

He'd barely made it three steps inside when a familiar voice stopped him.

"Emiya."

Shirou turned.

Rin Tohsaka stood with her arms crossed, leaning against the wall with practiced casualness. Her dark hair was tied back in her signature twin-tails, and her brown eyes studied him with an intensity that made lesser students nervous.

She was eyeing him closely as if she was trying to assess him, akin to solving a particularly irritating puzzle.

"Tohsaka," Shirou acknowledged, keeping his expression neutral. "Is there something I can help you with?"