AN : Alright, I am pretty sure a lot of you have questions. First among those are probably "What ?" and "Why ?", and in order to answer them, we must start … at the beginning.

September 16th, 2019, 6:20 AM (UTC +1) : On page 228 of the Spacebattles forum thread of the Roboutian Heresy (therefore referred to as "RH), the individual identified as "MalcadorLite" (therefore referred to as "the Source") jokingly suggests the idea of a crossover between the RH and the franchise known as Fate/Stay Night (therefore referred to as "FSN").

September 16th, 2019, 5:30 PM : While checking his notifications on Spacebattles, Zahariel (therefore referred to as "the Author") notices the Source's post. Initial attempts at dismissing the memetic infection fail within minutes. Less than half an hour after exposure, the Author opens a Word document and starts typing how such a crossover could possibly be done.

September 16th, 2019, 11:43 PM : After hours of writing, the Author finishes a first tentative draft of the mechanics of a crossover between RH and FSN, as well as a starting plot. In a fit of pique at having had his time consumed by the memetic infection caused by the Source, the Author publishes the draft on page 230 of the Spacebattles forum thread, vowing vengeance against the Source in the same post.

In the months that followed, I kept going back to that idea. I consulted the wikis, I watched the movies, I even installed an emulated version of Fate : Grand Order on my computer, losing dozens of hours of my life to that insidious, well-written time-vampire of a game. I wrote down the guidelines for an entire set of narrative arcs, all the way to the epilogue. I dreamt of the Fifth Grail War, of the great and terrible things that could happen then. I wrote the names of Servants and Masters, and painstakingly crafted the aria of a Reality Marble unlike any other. I conceived of an entire narrative arc constructed around the simple principle of the characters discovering the mechanics of the crossover they inhabited.

Eventually I broke down and realized that I wouldn't be able to get away from this.

And that's where we are now. You can find both of the original posts on Spacebattles, though the second one may contain some spoilers for this story. Most of what's written in it is no longer relevant – the first draft has gone through a lot of changes since then – but there are still elements that will be revealed in-story contained in it.

You don't need to have read the Roboutian Heresy to read this story, though knowing the lore of that alternate universe should make it fun to try and guess what is going on. What's different about Shirou in this timeline isn't a great mystery – for us, though : the poor bastard is going to have to work hard to figure out what's wrong with him. Knowledge of the Fate universe is much more important, since the bulk of that story will take place there. The needs of the crossover mean that I have had to change a few things about the setting, though those are only minor things, and will only come to light later in the story.

Unlike my other works, this story will be focused on the characters rather than the events surrounding them. It will be something different from anything I have written previously, so I will be grateful for your patience as I stumble with new writing challenges. For some reason, writing a dialogue between two teenagers is more difficult than writing a conclave between Lords of Chaos plotting the destruction of the Imperium.

It is also a crackfic, and NOT canon to the Roboutian Heresy. I cannot stress this enough. Elements of RH-lore revealed in this story may be later used in the Times of Endings, but that's something I will decide later. Keeping this story separated from the rest of my work will allow me to take what I write here less seriously. And on that note, let's discuss …

Pairings, which are arguably the very foundations of fanfiction writing yet something I myself have never had the occasion to try my hand at. This story is going for a Shirou/Harem pairing. Why ? Because it would be nice to write something nice and fluffy for once, and if takes the combination of the Nasuverse's existential horror with the grim darkness of the far future to bring some light to both settings, then by the living stars, that's what I shall do. I wrote most of this after watching the Heaven's Feel anime, so you may understand my desire to create a timeline where things aren't quite that depressing.

Let me tell you, it was fun coming up with the members of Shirou's harem, past the obvious ones.

The prologue and the first three chapters of this story are written at the time of publishing. The prologue is in this chapter, and the next three chapters will be published in short order if they haven't already by the time you read this. The publication of following chapters will depend on the reaction to this story – if no one but me is interested, I will still write it, but it will probably take a backseat to my other stories. My new year's resolution is, after all, to finish Warband of the Forsaken Sons this year, so choices will have to be made.

So … that's it. Thanks to Jaenera Targaryen for beta-reading this, despite her shock that I was actually writing the damn thing. I hope you find this interesting. Don't hesitate to tell me what you thought of it. If you have questions, I will also do my best to answer them.

Oh, and, MalcadorLite ? Entertaining as writing this has been so far, I shall yet have my revenge upon you. It may be delayed, but it will come, in time and in force.

Zahariel out.

December 2nd, 1994 AD – Fuyuki City, Shinto District

In what seemed like the end of the world, a child walked through Hell.

Burning buildings and bodies surrounded him. Beneath his feet were scorched earth and broken stones, and above him a crimson sky illuminated by the baleful radiance of a black sun. There were screams, though the child did not see anyone else alive. All he could see where the corpses of the dead, charred black by the flames, burnt almost beyond recognition. The air was thick with smoke, and something else, something that burned the lungs and soul of the boy as he forced himself to keep walking, despite the pain, despite the grief, despite the horror.

This was not something a child could do, however. With every step, part of him was burned away, making him more and more hollow. His name was one of the first thing to go, followed by the names and faces of his family. He forgot who he was, and when those memories were gone, he began to lose emotions as well.

Some of these he abandoned in order to keep going : fear, sadness, horror. He threw them into the dark flames that burned around him, so that they would not overwhelm him and stop him walking. Others were lost as the flames that were not flames spread inside him, consuming parts of him just as they had consumed the bodies of the dead. Of these, hope was the last, burned by the fire that was not fire. Yet still, the child kept going, driven by a determination he could not understand.

In the end, it wasn't enough. The child had lost too much, sacrificed too much of himself to the inferno. His body still responded his commands, but there simply wasn't a will left to drive it any longer. Why keep walking, why keep trying to survive ? Hollowed as he was, he couldn't think of any reason to not simply let go …

It was then that something else came, something beyond the flames and the devastation. Something which had been falling for a very long time, through time and space, drawn to the twisted light of this fire. Like the boy, it too was broken, having left much of itself behind as it tumbled through its own purgatory.

It had no flesh, no body, no presence in the material universe, for it was a thing of the spiritual realm. As it came in contact with the flames, it, too, began to burn, and despite the damage it had sustained, it retained more presence of mind than the boy still, and sought to escape the fire.

Seeking the closest place it could hide from the inferno, it burrowed into the boy's hollowed soul, seeping into the cracks of his spirit. In the supernatural heat of the cataclysm, the two damaged essences slowly alloyed together, and the boy took a deep, shuddering breath, twitching in pain as his lungs filled with the scorching air. Slowly, painfully, he forced himself back to his feet. Suddenly, he didn't want to die. He wanted to live, even though he had nothing left to live for.

But despite this sudden desire, in the end, his body was still that of a frail child. The heat and the smoke were too much, and he collapsed again. He crawled, on the ashes and the debris, no thought in his mind except to keep going. His limbs hurt so much, but he would not stop. He forgot about the flames, he forgot about the ruins, he forgot about the corpses. His world was reduced to the patch of broken ground in front of him, to the mechanical motion of pushing himself forward.

Then he felt something touch him, and he was lifted off the ground. He tried to cry out, to reach out to the scorched earth. How could he keep advancing if he couldn't touch the ground ?

His body turned, and he saw that he was held in the arms of a man, wearing a black coat covered in scratches and soot. He was looking at the boy, and as tears ran down his face, he was smiling. And that smile … the boy did not remember, but he felt that he should know … he should know what smiling meant …

Ah. Now he remembered. Happiness. That was what smiling meant, right ?

"I've got you," said the man. "Don't worry. You are safe."

He did not understand. He could not imagine what it would feel like, to smile like that. How could someone be so glad, so happy, just by having saved someone ? Something burned deep inside him, hotter even than the flames that had all but consumed him, and he wondered :

Could I smile like that, too ?

Time passed. To the boy, whose mind and body had been damaged so badly, it seemed to pass in a succession of flashes, stuttering forward before stopping.

The man who had found him in the flames, Kiritsugu Emiya, brought him to a hospital. The doctors didn't say it out loud, but the boy knew that they didn't expect him to survive. They still tried, though – they did what their duty, their oaths, compelled them to.

Later, the boy would look back upon it, and realize that they had been as desperate as Kiritsugu to save someone from the devastation. They bandaged his wounds and set up an IV drip to sustain him and ease the pain. They did other things, things that his hazy, empty mind did not recognize. But he knew it wasn't going to be enough. He could feel his body falling apart, unable to deal with the damage it had suffered.

He felt … angry. The thought that all he had gone through, that he had survived where so many others had died, only to die on a hospital bed … it angered him. It felt wrong, an affront to all those he had seen die in those flames. This, anger at the injustice of the universe, was the first emotion he felt since he had left all those pieces of himself behind amidst the flames. This wasn't fair, he knew. This wasn't right …

… But, once again, there was nothing he could do about it.

Time passed again, and he found himself laying on his bed at night, with Kiritsugu standing over him. The man visited him every day, but this time was different. In his hands, there was something golden, something which was turning into fine, shining particles, which sunk into the boy's body. He blinked, and time rushed in again, and it was daylight once more. He wasn't sure if that had actually happened. But he did feel that something had changed.

Whether it had or not, things did change after that. Slowly, the boy's perception of time corrected itself. His wounds, too, began to heal. Organs that had been almost cooked by the heat began to recover, and flakes of his skin fell off, revealing red, raw replacement in the places where the flames had touched him directly.

Several weeks after the dream of gold that might not have been a dream, the boy was told by the doctors that they now expected him to make a full recovery. What they did not tell him, but he heard anyway, was that no one else from the center of the cataclysm had survived. He heard the doctors and the nurses whisper of what a miracle his survival was.

This too wasn't fair, thought the boy. He had lost so much, cast away so many parts of himself, and yet in the end, if it hadn't been for that miracle, he would have died anyway. If miracles were real, then why hadn't a miracle come for all those other people who had been in the fire ? Why just him ?

Kiritsugu told the boy that there hadn't been any sign of his family. He told him that, if he wanted, he could adopt him, and continue to take care of him once he got out of the hospital.

The boy accepted. He wanted to remain near Kiritsugu. Perhaps if he did, he would learn more about the miracle that had saved him. More importantly, he thought that maybe, just maybe, he would understand how the man had been able to smile like he had when he had found him.

After completing the required paperwork, Kiritsugu gave the boy a new name, "Shirou". He took his new son home, and the slow, painful process of rehabilitation began.

"You are a wizard ?" asked Shirou to his father.

The two of them were sitting outside, watching the night sky. They did that often, even though it was getting cold – neither of them were disturbed by the lower temperatures.

"Yes," answered the older man. He had been the one to bring up magic, simply telling Shirou that he knew it straight out of the blue as they were stargazing. "Though the word 'magus' is preferred, and I hardly qualify as one in the first place."

Shirou pondered this new information. It had been six months since Kiritsugu had adopted him, and though he was getting better, it was still painfully obvious, even to himself, that his mental faculties had yet to recover from his ordeal. Slowly, deliberately, he put the pieces together.

"When I was in the hospital, and the doctors thought I was going to die," he said at last. "I woke up one night, and you were putting something golden inside me. Was that magic ?"

Kiritsugu nodded, looking lightly surprised that Shirou remembered it. "They were right : you were going to die. I … didn't want that to happen. I couldn't let it happen. So I used my magic to make sure you would survive. That's also why I thought you should know about it. The method I used to help you get back to health may have long-term consequences."

"What was that method ? That golden thing … what was it ?"

"It was Avalon, the scabbard of King Arthur. When worn by the King of Knights, it granted its owner agelessness, immunity to all diseases, and a prodigious regeneration. Since you are not King Arthur, it will never work at that level for you, but it is still powerful enough that it could repair the damage you had suffered before I found you."

Shirou spent a long time mulling over what his father had told him. Eventually, he asked :

"Can you teach me magic ?"

"Shirou …" Kiritsugu sighed. Evidently, he had known where that conversation might go. "To be a magus is to walk with death. Every use of magecraft carries the risk of death or injury. I don't even know if I could teach you, but I don't think I should. It will not bring you happiness, that's for sure … And furthermore, most magi … aren't good people. To them, the only thing that matters is the pursuit of knowledge, the discovery of new mysteries – that's how spells are called – and the mastery of the existing ones. They don't care if they hurt or even kill others. And you … magic cost you your parents, Shirou. It was magic that caused the fire, magic that nearly killed you."

Shirou wasn't sure, but he was quite certain this was not a conversation a responsible adult would have with a seven-years old (if that was Shirou's age : they couldn't know for certain). But then again, neither he nor Kiritsugu were normal people. He knew that much, at least.

"But you saved me with it," argued Shirou. "That means it can be used for good, right ?"

"I suppose so," Kiritsugu grudgingly admitted. His face took on a wistful expression, as if he were looking at something far, far away, that only he could see. "In the end, it's just a tool. How you use it is up to you. It's just that most people who practice it tend to abandon their morals very quickly."

"Then please, teach me."

"Why are you so insistent ?" sighed Kiritsugu.

"Because … because I want to be like you, dad. I want to save people, just like you did with me !"

Kiritsugu smiled again. But this time, his smile was far more bitter than the first time Shirou had seen him.

"You don't want to be like me, kid. Trust me. I wanted to save people, too, when I was your age. But in the end, you can only save so many. There will always be those you cannot save, and it will eat at you from the inside … I don't want you to make my mistakes, Shirou."

"Even if you cannot save everyone, you should still try," argued Shirou. "And saving one person is still better than none, isn't it ? Otherwise, why did you save me to begin with ?"

Kiritsugu looked shaken for a moment, then he smiled again, more softly this time.

"Fine," he sighed. "You win. I will teach you what I know, for what it's worth."

Kiritsugu Emiya sat in his garden, watching the stars and knowing he was going to die.

Of course, that knowledge wasn't exactly new to the retired assassin. From the moment he had stumbled away from the Grail, his body and Magic Circuits poisoned by the spiteful curse of the corrupt thing that had infected the artefact, he had known his days were numbered. Now, however, he had entered the final stretch of his miserable life.

There were methods that he could have employed to prolong his life : a lifetime of wandering in the dark places of the Moonlit World had left him with plenty of contacts, though he had burned most of the favors he had been owed in the preparations leading to the Grail War. Still, he could have found someone who could have bought him a little more time … but at what cost ?

When he had told Shirou that magi weren't nice people, he hadn't been so much understating the truth as outright lying to the boy. There were decent people among magi, that was true. But the overwhelming majority of them were somewhere between psychopaths and outright monsters. He should know : his father had been one of the latter category. Somehow, Kiritsugu doubted that any method of countering the Grail's curse wouldn't come with a cost he refused to pay.

He had committed too many sins, killed too many people. If this slow death was his punishment, then he couldn't argue that it was a deserved and just one. It would almost be enough to make him believe in karma, if he hadn't seen the things he had seen.

But if the curse was his punishment for the lives he had taken, then perhaps Shirou was his reward for those he had saved, he sometimes thought to himself. Not that raising Shirou had been easy. Admittedly, Kiritsugu's only experience with parenthood had been Illya (god how he missed his daughter), and she had been the daughter of a homunculus created to serve as a Lesser Grail. But even he knew children were bundles of instinct and energy, whose parents had the job of teaching, by example and by lecturing over the course of several years, how to function in society.

However, Shirou's instincts had been lost in the fire, and the kid had had to rebuild the whole model for his behaviour. Where other humans had a selfish core paved over with the laws of civilization, Shirou was his ideals. Helping others was his default action in all circumstances, and while it had made for interesting parent-teacher conferences, it worried Kiritsugu. A lot.

He had trained Shirou in magecraft because he had been terrified the boy would have tried it on his own otherwise, a recipe for disaster if ever there was one. Given that the brat had tried to use his own nervous system as an improvised Magic Circuit the first time Kiritsugu had had him perform the most rudimentary form of magecraft, the dying man shuddered to imagine what could have happened then. It was unlikely Shirou would have survived for long before accidentally frying his own brain trying to perform something other magi would have considered the simplest feat of magecraft.

Using a combination of simple spells and one of the few Mystic Codes he had kept from his time as the Magus Killer, Kiritsugu had identified Shirou's Element and Origin after the boy had learned to activate his Magic Circuits properly. To his surprise, the boy was an Incarnation : both Element and Origin were the same, in this case, "Sword".

Considering what was implanted within the boy and what had happened to him, Kiritsugu supposed that wasn't impossible. All that Shirou had been had been melted down, and by placing Avalon within him, Kiritsugu had unintentionally provided a cast for the boy's nature. Perhaps Avalon was also partly responsible for Shirou's behavior, an echo of the scabbard's former owner influencing his development. Kiritsugu could only hope Shirou wouldn't end up like her.

Being an Incarnation was incredibly rare, and it meant that training Shirou had been even more difficult than Kiritsugu had anticipated. The Magus Killer had never been a master of Magecraft, and what passed for his own mysteries were bastardized versions of the Emiya's bloodline's secrets combined with what he had gleaned from other freelancers during his career. In addition, with his crippled Magic Circuits, he had been unable to demonstrate anything for Shirou to learn from.

As a result, by the standards of the Clocktower, Shirou's abilities as a magus were just short of abysmal. He had a knack for, of all things, structural grasping, and was at a base level of competence at Projection and reinforcement. Shirou's Incarnation status meant that he could Project (though the boy stubbornly kept calling the process "Tracing") bladed objects much more easily than anything else, and to a much greater level of detail. For now, the kid was limited to kitchen knives, but he had already expressed interest in learning how to use real swords.

That wasn't so bad, but it was his iron-clad morals that would forever keep him from being first-rate in the eyes of London's self-styled elite. Shirou would never accept harming anyone else in pursuit of greater mysteries – not when the sole purpose behind him learning Magecraft in the first place was to help other people. Which was perfectly fine as far as Kiritsugu was concerned.

The issue, of course, was that Shirou was still entirely too willing to hurt himself in order to further his mastery of Magecraft. Kiritsugu had lost count of how many times the boy had damaged his body by over-reinforcing it. If not for Avalon granting him the ability to heal from pretty much anything eventually, the former Magus Killer was dreadfully certain that his son would have either killed or crippled himself long ago.

Of course, knowing that he could recover from injury faster than other people hadn't helped the boy's willingness to put himself at risk. That regrettable tendency was why Kiritsugu had left Avalon within his son, despite the effects it had had on his development. He had spoken to Shirou at length about the scabbard's properties, explaining to his son that while it could heal him beyond the means of modern medicine, it could do nothing for him if he was dead, and there were definitively limits to its regenerative abilities.

In the last months, he had also forced Shirou to swear to him to be more careful, knowing that he would not be there to take care of his son's messes much longer. Avalon may heal him, but it didn't erase the medical records that showed his injuries or make the doctors forget that he should have taken months to recover. The kid was terrible at hypnosis, although Kiritsugu's lacklustre teaching was probably to blame for that one rather than Shirou's own deficiencies.

He could make someone forget what had happened in the last hour or so and leave them to wake up with a massive headache, but that was about it. They had been forced to halt that training when the last of Kiritsugu's magical abilities had left, since he could no longer erase the memories of the vagrants they had used for training. And by the Root, what a challenge it had been to convince Shirou that was necessary … he had been forced to spend a good chunk of money on help to the homeless to assuage the boy's conscience, even after explaining to him that knowing how to erase memories would one day allow him to save someone's life.

Kiritsugu had also taught Shirou enough of Magus culture to make sure that the boy knew that he had to keep away from the Clocktower. He had revealed enough of his own past, keeping the sordid details to himself. Shirou knew that the name of Emiya was infamous in the Moonlit World, and that if he ever walked there, he would have to watch his back for his father's enemies. He had also told him of the inhumane methods far too many of the magi were willing to use : if Shirou's nature as an Incarnation were discovered without someone ridiculously high placed to protect him, his fate would be too terrible to contemplate.

Often, looking at Shirou, Kiritsugu felt like he was watching a younger version of himself as he had wanted to be. The boy spent every moment not dedicated to chores, his education or his Magecraft training himself in other ways, building his muscles and stamina. Shirou wanted to make sure that, if someone needed help, he could give it to them.

But while the core principles of Kiritsugu and Shirou were the same, the boy could not even conceive of the path the Magus Killer had walked. Despite all that he had endured, despite the horrors he had witnessed, Shirou was too pure, too innocent. Kiritsugu could only hope that life would be kinder to his son than it had been to him, and would not shatter that innocence too cruelly. Every time he saw Shirou risk himself to help someone, he prayed to gods he no longer believed in that his son may be spared of the path he himself had walked to its bitter end.

At least he would die knowing that his son wouldn't repeat his greatest mistake. There would be no more attempts to recreate the Heaven's Feel in Fuyuki, he had made sure of it. The Heaven's Feel, the attempt by some of the greatest magus families to reclaim a lost Sorcery, would be brought to an end, not in an epic confrontation between god-like Servants, not by a Master finally winning the damn thing, but because of the machinations of a dying mercenary with no magic left in his body but the curse killing him. Serve the Einzbern right for stealing his daughter from him and refusing to respond to his warnings about their masterpiece's corruption.

Of course, it was unlikely his daughter would even be alive in fifty years, when the magus families would expect the next Grail War to take place. He had known from the moment Illyasviel had been born that she wouldn't live long, and what the Einzbern had done to her in that accursed castle had only shortened her lifespan …

His gaze came down from the stars as he heard something crack. The tea cup he had been holding was starting to break in his grip as he subconsciously tightened his hands into fists. He forced himself to take a deep breath and relax, ignoring the pain that flared within his lungs at the action. He couldn't save Illya. He had tried, several times, and each of his failures had brought him a little closer to death. Now … he probably wouldn't even survive the flight to Germany.

"Dad ? Is everything okay ?"

Shirou's voice, coming from the kitchen behind him, caught Kiritsugu by surprise. He turned to see his son standing there, looking at him with worried eyes. He must have heard the sound of the cup cracking.

"Yes, everything is fine. Come." Kiritsugu patted the wood next to him. "Sit."

Putting the dish he had finished cleaning into the cupboard, Shirou walked to Kiritsugu's side and sat down, looking at him with curiosity battling worry in his eyes.

"Do you remember where I found you ?"

The boy nodded. Of course he remembered. He would probably never forget what he had seen, what he had experienced. Another sin to add to the list by which the Magus Killer was damned.

"I told you once that the fire was caused by Magecraft. I think … I think it's time I tell you a bit more about what happened."

"There is a ritual that is called Heaven's Feel, but is more commonly known as the Holy Grail War. It takes place in Fuyuki, and pitches seven magi against each other in a death match. Every participant is called a Master, and controls a Servant, a humanoid familiar created from the legendary heroes of the past. The last magus standing will claim the Holy Grail, an artefact that can supposedly grant any wish made upon it … Or at least, that was the idea. When I heard about it, it was like all my prayers had been answered. I thought that, with it, I could change the entire world, make it a place where no one had to suffer, no one had to be unhappy. A place without violence."

For all his issues, Shirou wasn't an idiot. "So … what went wrong ?"

He told him. He didn't go into too much detail – he didn't tell him the names of all the Servants involved, nor the existence of Irisviel or Illya (he could just imagine Shirou storming the gates of the Einzbern Castle and getting slaughtered by homunculi guards). But he told him about the mechanisms of the Grail War, about the battles that had been fought between superhuman Servants, and the destruction they had caused. He told him about how, against the expectations of the high-born magi of the Clocktower, he had managed to claim victory in the War. He told him of the Grail – and, at the end, of the lie it had been.

"The Grail was – is – corrupted," he explained. Again, he kept the details to himself – there was no need for Shirou to know about the thing that had dwelled within the Grail. The kid had enough nightmare fuel in his own memories, and anyway, he himself had never learned just what that thing had been, or how it had ended up in the Grail. "I am not sure whether it would ever have worked as intended, but now, it is only a monkey's paw …"

He stopped, realizing that Shirou had no idea what the expression meant.

"I mean, it will twist any wish made upon it to cause as much destruction and suffering as possible. When it activated at the end of the War, I realized that all that I had done to claim it, all that I had sacrificed in the hope of getting my wish, was in vain. I ordered my Servant to destroy it before it could destroy the world … and that destruction caused the fire in which I found you. Even to this day, the strength of the curse that was unleashed then lingers in Fuyuki Central Park, just as it does within my own body."

Even after five years, it was difficult to keep his voice from breaking as he remembered.

"You did the right thing, dad." He blinked, forcing back tears. Shirou was looking up at him, his hands around Kiritsugu's trembling own.

"How can you say that ?" he choked out. "If I hadn't -"

"If you hadn't been there," said Shirou far too calmly and reasonably for a child his age, "if you hadn't taken part in the War, then it would still have happened, right ?"

He was forced to nod. The Heaven's Feel would have found seven participants regardless of his presence in Fuyuki.

"And if you hadn't been here," pressed Shirou, "someone else would have ended up winning and facing the Grail. If that person was a magus like the ones you described to me, what would they have done ?"

Kiritsugu smiled bitterly. This wasn't a new argument to him. He had known for a long time that, had he not participated in the Grail War, things would likely have ended up much, much worse. The Einzbern would have found another representative : likely a typical magus who wouldn't have cared for the corruption of the Grail, only that it could provide them with a path to the Root.

And the thing he had seen would have been capable of such a thing … but the cost would have been astronomical. He very much doubted there would have been anyone left alive on the planet afterwards. Irisviel would still have died, turned into the receptacle for the prana of the Heaven's Feel. Illya … never would have been born at all.

A detestable part of him wondered if that wouldn't have been kinder that the life his daughter had ended up with.

"See ? Because you were there, because you fought for what you believed in, you ended up stopping an even bigger evil from happening."

"Even so," he said, "just because things could have been worse does not absolve me of my crimes. There is always a worse scenario, and it is never an acceptable excuse."

"So what ? We should just give up ? Do nothing, because anything we do could have bad results ?"

"No, but we all have to live with the guilt and the knowledge that while things may have been worse, they could also have been better … and maybe we have to accept that sometimes, no matter what we do, the result may end up the same."

It was something he had come up with in his ruminations on the Grail War. Thinking back, his victory had been all but a miracle. Sure, he had been more prepared to actually fight in a war than most of the other participants, his professional methods giving him an edge over those who relied on their mysteries in battles involving Servants who were so far beyond modern Magecraft it may as well not concern them at all. And he had had Artoria to help him, even if she had been … difficult to work with.

But.

The fact that the city, that the world had survived the Fourth Grail War, was nothing short of miraculous, and Kiritsugu had long stopped to believe in miracles, before the possibility of winning the Grail had led him into deceiving himself that his ideals may actually be accomplished, after all.

Why had the Einzbern, known for their pride in simply growing the people they needed, called upon a disreputable mercenary to be their champion in the Grail War ?

Why had the one meant to be sacrificed to host the Grail's power developed a mind and heart of her own, falling in love with one of the Masters and reawakening the humanity he had long since cast away ?

Why had Rider's Master been a boy with no idea how to fight in the Grail War, rather than a callous magus who would have been able to compel the Servant's obedience and make full use of his Noble Phantasm ?

Why had the Grail chosen a random serial killer as a Master, resulting in Blue Beard of all people being summoned and leading to his first suspicions that not all was well with the Grail ?

Why had Archer held back so much instead of crushing them all with his overpowered Noble Phantasms, claiming the Grail and unleashing its horrors upon the world ?

Why had he, the one Master whose pride and ambition were the least likely to be willing to ignore the Grail's corruption and claim the prize no matter the cost, been the one in a position to destroy it ?

There was a painfully obvious answer to those questions, one that had come to Kiritsugu mere months after the end of the Grail War. Counter Force. Alaya's instrument, the collective will of Mankind to protect itself by making small changes that resulted in disasters being averted.

He would not – could not – tell that to Shirou, though. Knowledge of the Counter Force was a poison. It led to paranoia, to self-doubt and existential crises. Shirou had enough problems without being forced to question whether his own actions were being manipulated by an unknowable entity.

It did haunt him, though. Just how in control of his actions had he really been during the War ?

Shirou's face hardened. Though the boy was far more reasonable than any other child his age Kiritsugu knew, there was steel laying just under the surface. It took a lot to reveal it, but Kiritsugu's defeatist words had been enough.

"I refuse to believe that, dad. What we choose to do matters. No matter the consequences."

There it was. The one thing that worried the Magus Killer most about his son, during the dark of the sleepless, pain-filled nights. Sometimes, when Shirou discussed his ideals, his determination to save others as he had been saved, Kiritsugu would catch a glimpse of something in his son's eyes. He could never identify what it was, but it was there, and it made him very, very worried. Somehow, his instincts screamed at him, whatever it was he saw would play a huge part in whatever future awaited his son.

"Perhaps you are right," he sighed, looking back up at the stars. They shone, just as they had when he and Irisviel had looked at them together for the first time, in the cold gardens of the Einzbern castle. Was there anything up there, he wondered, that cared for their fates ?

He doubted it.

"I have taken steps to ensure that the Grail War can never happen again," he continued. "I have set explosive charges along the ley lines that will detonate in about twenty years, severing the flow of energy necessary for the ritual to take place. They are buried deep enough and are well hidden that no one will be able to find them without knowing where they are, and I haven't told anyone. When the charges explode, the Grail will be cut off from the land, and it will wither and disappear long before anyone notices, taking its corruption along with it.

"Still, if you are in Fuyuki in, say, fifty to sixty years, when the next Grail War is supposed to happen, you better be careful. There will be an investigation by the families that set up the Grail War, and they won't be happy when they discover my sabotage. Come to think of it, you should probably make sure not to be anywhere near this town at that time. Having the name 'Emiya' will paint a target on your back. And don't think that you need to stay there to make sure that the investigators don't hurt anyone while looking for you, alright ? Unless you are willing to surrender to them – and you better not, or I swear I will find a way to return from the grave to make you regret it – that would only result in a conflict that would cause far more damage than they would if left on their own."

"I understand," answered Shirou, his head bobbing up and down, eyes wide at his father's sudden seriousness. He didn't, and likely never would, but Kiritsugu was fairly certain he would obey. He glanced at the clock, and frowned. It was already past ten o'clock, and Shirou had school tomorrow.

"Go to bed, Shirou."

"Okay." He paused. "Don't stay out too late, alright ? It's getting cold at night."

Kiritsugu absent-mindedly nodded. After Shirou had left, he took another sip from the cracked cup. In the night sky above, the light of distant stars continued to shine, indifferent as ever to the struggles of those who lived on the Earth.

The tea, brewed by Shirou – it had been months since the last time the boy had allowed his father to enter the kitchen – had grown cold. Even so, it still tasted really nice.

A few days after that conversation between father and son beneath the stars, Kiritsugu died. Shirou found him one morning, sitting in his chair facing the window, his eyes closed, his expression peaceful.

Shirou, for all his many issues, wasn't an idiot. He had known Kiritsugu's health had been deteriorating since the man had adopted him. He had seen the twitches, the trembling hands, the times his father had needed to stop what he was doing and wait for a sudden surge of pain to pass.

He still cried.

The funeral was taken care of by the Emiya's neighbours, the Fujimura family. Shirou knew that his dad had some kind of accord with the Fujimura patriarch, Raiga, who was the leader of the local Yakuza gang. His granddaughter, Taiga, was named as Shirou's guardian in Kiritsugu's will – and, thanks to Raiga pulling some strings, the young, wild woman was actually granted the guardianship without issues despite the fact that no judge in his right mind would have even considered it.

Time passed. Shirou went to school, grew up, continued to practice his Magecraft and train his body. As he grew up, he began to practice his beliefs, helping many people across Fuyuki, though never in as dramatic a fashion as he had been helped by Kiritsugu. In his school and in the town, he grew a reputation as a good, helpful boy, always willing to help others. With the unspoken protection of the Fujimura group, no one dared try to mess with him – at least no more than once.

No one other than Kiritsugu saw whatever it was the Magus Killer had glimpsed into Shirou's eyes that frightened him so much for his son's future …

… But it was still there.