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.

---

Fate: Emblem Heroes

Chapter 1: Prologue – Rebirth by Fire
​

---

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.