Disclaimer: If I get things wrong that can't be explained by the butterfly effect, then take a deep breath, because it wouldn't be true to the Nasuverse if it was 100% consistent.

Fate/stay night is one of my favorite visual novels, and I love almost every character to death, and I hope that comes through (no matter how badly I might bully them). I saved up a ton of quartz for Gramps, and then I got two copies of him in the same 10-roll, so me writing this fic was pretty much a divine mandate from the gacha. This fic does assume you're familiar with the original, so I gloss over a lot of the exposition, and I will be spoiling certain revelations (from the Fate route and Heaven's Feel especially) in a pretty offhand way.

I won't stop you from reading, but I'd recommend checking out the original first! Just skip the sex scenes. I'm going to try to post roughly every two weeks, and I've got almost 50k written as I publish this, so I've got a lot of cool stuff lined up!

Fuyuki City burned.

The swordsman was neither happy nor unhappy with this fact. Collateral damage was something he sought to avoid, but when the enemy was as powerful as the man in the golden armor, destruction was a natural byproduct. They stood in what had, a few hours before, been an idyllic park, the sort of green oasis that civilization had used to brighten its urban sprawls since before the swordsman had been a man. Now, it was an inferno, towering columns of flame roaring even where there should not have been enough fuel to burn. Great furrows had been carved into the dirt and grass, blasted apart by the sheer force of their violence. A playscape for children lay shattered around his feet, bars of metal twisted and torn and bent into something unrecognizable and skeletal. Smoke choked the air. If there had been people here before the battle had come to this place, most were either gone or dead. In the distance, someone wailed, the sound high and mournful and broken.

High overhead, a great circle of black hung in the sky like a dead sun, seeming to draw all light into itself. If the swordsman stopped and focused, he could see the fine threads of life, such that were left in the conflagration, being drawn inexorably upward, pulled into the negative space the way water naturally contorted to fill an empty cup. The Grail was almost ready. There remained only a single sacrifice needed to open the gate, and the power surged against its bindings, hungry to be used. To be unleashed. Thrumming, hateful power deep within his bones set him on edge.

That hadn't happened in a long time. The swordsman had seen everything, he'd thought. Nothing surprised him. Nothing affected him.

The so-called Holy Grail shook him to his very core.

Why he was here, he didn't know. There had been an irregularity. Something that broke the rules as he intuitively knew them. His essence was not meant to be distilled into the form of a Servant. He was more than that. When the summoning had come, however, his spirit origin had been carved and contorted and mangled to fit a vessel that was never meant to hold one such as him. No longer Grand.

He considered the weight of the sword in his right hand, examining it quickly for damage. A normal man would not have been able to lift it, yet to him it weighed little more than a feather. An ordinary broadsword, suffused with his will. Not a Noble Phantasm at all, for there was no record of it, no legend to give it power. As far as history was concerned, it had never existed. It was black as the armor he wore, its tip eternally stained with fresh blood. A symbol of his grim duty.

Strapped to his other arm was a massive black shield, spiked and cruel, a skull with burning blue eyes emblazoned across it. A bulwark of steady darkness against the golden man's all-consuming light. The swordsman had a duty, and he had carried it unto death, and beyond. So long as the continued existence of the human race remained God's will, he would trim rotting branches, to keep the blight from spreading to the rest of the tree. He was no agent of the Counter Force, no Guardian summoned after the fact into the worst evils mankind could engineer. He worked proactively. Not often, but just enough to nudge history into something it was meant to be. Something that would continue. He was who he was. First among murderers. The righteous blade, armored in darkest shadow.

Allowing his Master to unlock the Grail would bring untold death and destruction to the city. All the evils of the world would pour forth to consume what they could, to grant his Master's benevolent wish in the most destructive way possible. He knew this the way he knew the color of the sky, or the taste of water, or the heat of the desert sun. He was bound to help him achieve this.

There was a contradiction in that, the swordsman knew. To be sworn to protect the world, while at the same time, doing everything in his power to help usher in unnatural, malevolent death. Two things guided his path, allowed him to reconcile the combating duties.

The golden man - the Archer of this War - raised his right arm. The armor covering the limb had been shattered, and his bloodied fingers trembled with weakness. A glancing blow, early in the fight, but it had been enough to break the gauntlet open. A hundred golden gates opened in the air around him, golden light hazy in the smog. His arm thrust toward the swordsman, and droplets of blood flew through the air, followed by weapons of every conceivable make and shape. Every one authentic. Every one a Noble Phantasm.

The first: he had been summoned into this war for a reason. The rules had been broken to allow his participation. If God had deigned to allow His servant to become a Servant, there was a reason for that. Some ultimate need that would only be fulfilled by his victory in the challenge placed before him.

The swordsman was a great hulk of a man, weighed down by armor thick enough to crush a mortal, but when he needed to move, he flowed like water. Every movement precise, calculated. Exactly the motion he needed to avoid each weapon, and not an inch more. Behind him, dirt sprayed and fire bloomed, the ground torn asunder by the assault. Concussive blasts of sound and force filled the air. Dust settled onto his armor, into his cloak, but he remained unharmed.

The distant screaming had stopped.

The second: the swordsman's Master was a good man. He did his best to hide it, and his methods were familiar, but his wish was not an evil one. Pragmatic, but not cruel. More than that, he was perceptive. The swordsman thought that when the time came, he would recognize the Grail's true nature and reject it. It was a kind of faith, and there was protection in faith. If he didn't, though, if he reached the Grail and decided the end was worth the price, he would use his last command spell to end the swordsman. The swordsman would make him use it.

A small part of him took comfort, though, in the idea that his Master using the Grail would be the lesser of the two evils. Though he had never met Archer's Master, a Servant always matched their summoner in some way. The catastrophe would be total.

Archer's teeth clenched, the lines at the corners of his eyes tightening. He hid it well, but the swordsman had seen enough desperation in his millennia to recognize it when he saw it. Archer was a man who was used to being the most powerful in any given situation. How long had it been since he had needed to try to accomplish anything? The swordsman had taken stock of the other Servant the first time they'd clashed, and he had found little reason to revise his initial assessment. Archer was powerful; tremendously so. In a contest of raw strength, the swordsman knew that they would be evenly matched. This, however, was the difference between them.

The swordsman had been born a man. The lowest of the low. Everything he was, every scrap of power he possessed, he had worked for, clawing for every inch until his fingers were bloody, until his nails bent back and broke. Training his body and mind into razor sharpness, and beyond. He knew what it was to be powerless, and he would never take that power for granted. He knew what it was to believe in something.

The Archer had always had everything. He knew not what it meant to struggle. To fight. He was used to executions, not battle. He was untrained. Untested. A child with the ultimate power to destroy, and no guiding values to wield it in service of. Arrogance was not faith.

The swordsman walked slowly forward, smoke swirling around him like a cloak. Each step was heavy and inevitable.

Archer took an unconscious step back, then grit his teeth again. There it was. Petulant resolve. If he was going to die, he was going to take the swordsman with him. He spit onto the ground, and it was bloody. "Mongrel! You don't know who I am. You should be bowing before me."

The swordsman didn't reply. Crunch. He threw the shield away, letting it thump quietly to the ground. He had no more need of it. All around them, an unseen bell tolled, slow and bone-deep. Crunch. Even the fires around them flickered and seemed to recede in terrified respect.

"You look upon Gilgamesh, King of Heroes!" Archer drew himself to his full height, arms spread wide. His breastplate was dented and scuffed, only one of his arms still armored. "Divine blood runs through my veins, and all the world belongs to me!" He was almost screaming, bloody spittle flying from his lips

Crunch. The bell sounded again, in time with the swordsman's slow steps. "Hearken, Gilgamesh, King of Heroes. The evening bell tolls thy name."

Gilgamesh, to his credit, held his ground. In his right hand, a strange sword appeared. It looked more like a strange, stunted lance than a sword, but the swordsman recognized its power in an instant. "You are my subject! My property!" He raised the sword, slowly, and the air pulsed around it, smoke spinning lazily, growing faster and faster. "You will end because I demand it! I am Gilgamesh! Look upon Ea, mongrel, and know that your end has come!"

The distance between them closed, his walk never more than deliberate. "Wings of death, wilt thou sever his head?"

The power around Ea coalesced, turning red, the maelstrom churning at a fever pitch. The bell stopped, and though they still burned, even the sound of the flames faded to nothing. His voice roared, angry and afraid and disbelieving. "Enuma-"

"AZRAEL."

Even the swirling of the smoke went still. The swordsman stood beside Gilgamesh, sword extended straight out before him. Ea sputtered and sparked and grew dim.

Gilgamesh stood as though he were locked in place, his body trembling, his arm still extended. His eyes were like dinner plates, and his mouth worked, trying to form words. Nothing came out but a quiet hiss of breath. The tip of the sword shook violently.

The swordsman turned his sword over in his hand, resting the point down onto the burned ground. He inclined his head, one last gesture of genuine respect. "Return to the Throne, King of Heroes. This world holds no place for the faithless."

Gilgamesh's head toppled backward, and a moment later the rest of his body pitched forward. The golden light consumed him before he hit the ground.

All around him, the fires still burned. Sound returned to the scene. Smoke still filled the air. Above him, the darkness grew deeper. The vessel filled. As motionless as a statue, Hassan-i-Sabbah, the Old Man of the Mountain, first of the name, waited for his Master to return. To return, and to make his choice.

The fate of the Grail was no longer in his hands.