Author Notes: Hey guys.

I know, I should've continued FoS, but I was stuck in the next chapter. There is some problems in it that makes me want to pull my hair out.

So I decided to just post this one instead.

I don't know where the idea comes from, but it just struck me as I was travelling on a plane a month ago. It was a 7 hours journey, I was bored and was in serious need of humor because everybody around me were snoring and I couldn't sleep. There was even a kid who almost kicked me in the face from across the aisle, and he was doing it as he was sleeping.

(As for REQUIEMCROSS and Masterx01 (if you're reading this), I will answer your PMs as soon as I could.)

Warnings: Un-betaed, possible OOC-ness and possibly wrong knowledge about Nasuverse or Harry Potter. This fic was to make me happy among snoring passengers and a kungfu-lover kid across the aisle, so I wasn't really focusing on the details. But if there's any mistakes or suggestions, feel free to voice it out (in a more friendly manner, please.)

There would also be some minor alteration in the original Fate route. Shirou and Rin in this fic are from Fate/Stay Night: Unlimited Blade Works while Archer and Arturia are from Fate/Stay Night (2006). Archer is Shirou Emiya from the Fate route, but because he became a Counter Guardian he failed to be reunited with Saber in Avalon.

Disclaimer: I don't own Nasuverse or Harry Potter.

What a Coincidence

Fate/Stay Night x Harry Potter

...Or was it really a coincidence?




"Here lies King Arthur...until needed once again to vanquish Britain's enemies…"

- Anonymous -

Arturia Pendragon was bored.

Yes, her being bored was unheard of, but staying in Avalon for God knows how long would surely make even the most stoic warrior succumb to acute boredom.

Don't get her wrong. Avalon was the most beautiful place she had ever set her eyes on. There was an endless expanse of grassy hills, and the sky was the bluest she had ever seen. She was granted a comfortable house to live in, which faced a tranquil lake that was home to swans and many other wildlife.

Truly beautiful. Like those panoramic views Arturia had seen on the pamphlets Taiga had brought to Shirou's house one day.

However, her fascination quickly dwindled the moment she realised that she wouldn't see Shirou anytime soon.

If ever again.

'The Fates are cruel, indeed,' Arturia lamented. 'For they had allowed Alaya to trick me into a pointless war for a tainted wishing device, only to trap my soul beyond my death when I'd finally found the only person I've ever truly loved.'

Stupid Merlin for giving her Avalon.

...Then again, if he hadn't, she wouldn't have met Shirou.

Arturia sighed.

She didn't know how many days or months or years had passed. Memories of her stay with Shirou, of her growing feelings towards him and of his promise to find her again constantly filled her mind like a broken tape.

Yet nothing in Avalon had changed. Forever beautiful, but no longer breathtaking.



"Aaarrghh!" she groaned loudly. "When will you ever fulfill your promise, Shirou?! It's been, what, centuries!"

Arturia rubbed her face and sighed. Now, she was feeling guilty for blaming Shirou for that. She admitted it wasn't really his fault since finding her in some magical place (whose one of its purposes was to conceal her from the World) was pretty much impossible, but she couldn't help -


She jumped when, out of nowhere, a church bell-like sound reverberated throughout Avalon. Before Arturia could even do anything (like don her armour or curse or something) her body was already engulfed in motes of light. It was so bright that her sight had failed her, but she was sure she heard - in need of her crush her enemies once more…

- before her body was squeezed from all sides until she...came out from somewhere.


For some reason, Arturia couldn't open her eyes. A thick blanket snugly wrapped her shivering body and it was all so confusing that -

"Narcissa, dear, it's a girl!"

- she could only scream again.





"Kaleidoscope is a True Magic. One of the reasons it's called exactly that is because the moment you fuck up, you'll be at the wrong side."

- Kischur Zelretch Schweinorg, the Wizard Marshall -

Tohsaka Rin was a genius.

She had successfully mastered jewel magecraft at a young age. She had turned out to be a pretty decent and normal woman despite the psychopath of her guardian. She had managed to survive the Holy Grail War despite her Servant betraying her. She had even attracted the Wizard Marshall's attention and was made an apprentice in the Second True Magic, Kaleidoscope.

Rin thought she was truly a genius, but she had figured early on that geniuses usually don't have the best of luck.

Or maybe the Lady Luck hated geniuses - in particular, her - because her projects would always end up in failure due to some miscalculations or careless mistakes.

At least, for most of the time, Rin realised her errors and could quickly fix it. Nothing went really bad so far.

For most of the time.

Not this time, though. Perhaps the Fates hated her too and, together with the stupid Lady Luck, finally decided to give Rin the worst luck (like a minus luck, really) on that particular day.

"Aaaaaahhhhhh - !"

Stupid Fates. Stupid luck. Stupid Zelretch. Stupid magics. Stupid Archer. Maybe stupid Shirou too, just because.

Colour swirled around her. She felt her body being flung around helplessly like a ragdoll. Bile started to rise in her throat and fuckk -

Rin was about to spew out rainbows when things suddenly went dark. Then, a rough squeezing as if she was a sauce bottle before she finally emerged from...from somewhere.


"It's a healthy baby girl!"

"Whaaaaaaaaa - ?!"

A tiny part of her felt bad towards Shirou, because he was there when she'd fucked up.





- Emiya Shirou (when he got dragged into Rin's spectacular fuck up) -

Emiya Shirou loved his girlfriend, so he wouldn't fault her for dragging him into her fuck up.

He figured Rin was a human too, so it was okay for her to screw up sometimes.

Thus, naturally, he cursed Archer instead.

Stupid Archer!

Rin's Servant didn't deserve the E-rank luck. It should be zero luck, if not a minus, because his luck must've brought bad luck to the others around him. It was seriously stupid and unfair that the jerk got ten times more luck than average people.

Look at Rin. It was all Archer's fault that Rin's luck had plummeted so far down there.

...Okay, maybe it wasn't all Archer's fault because Shirou might've also indirectly contributed to Rin's failures. After all, he had dragged Rin along (or, actually, Rin dragged herself along) whenever he did his 'Ally of Justice' thing. That must've stressed her out, for sure, because she had to compromise her concentration and her brilliance to deal with him. Or, as she had always pointed out, his fantastic stupidity.

But still.

Stupid Archer.

A few moments of stomachache-inducing waves of rainbows later, his world turned dark. Then, some uncomfortable squeezing, and finally -


Multiple assaults of magical scents around him must've confused him so much…

...that Shirou failed to realise his scent.




"Sorry, I was a few minutes late."

- Alaya, the Will of Humanity -

Archer sneezed.

"It must've been that retard again," he grumbled.

It had been a few years (he assumed, since Alaya wasn't magnanimous enough to give him a clock or a calendar or something) since his last summon to the latest Fifth Holy Grail War. And, as per normal, he had failed his personal mission again. Archer was truly irked that after so many times being called upon as a Servant, and after so many parallel Fifth Holy Grail Wars, he would always fail to kill his younger self.

It was as if that brat was blessed with some stupid divine aegis that Emiya Shirou could be killed by anything but him.

Like, what the fuck.

Archer pulled his hair out in frustration. Then, like a deflated balloon, he sighed.

'At least,' he thought wistfully, 'I got to see Arturia again.'

It spoke volumes on how much he loved her that centuries of working as Alaya's lapdog hadn't managed to deprive him of memories on her. Most of them were now vague, but he could still remember the joy and tears he'd shared with her. He could still remember the day he first laid his eyes on her during her summoning, and of his promise to her…

Archer sighed again. Ah, yeah, that promise was impossible to fulfill to begin with. But his heart still ache painfully whenever he remember his vow to find her again.

'It's been, what, centuries? She must've been frustrated, being alone in that faraway land of Avalon.'

His gloom-and-doom moment was cut-off when he felt the familiar tug of Alaya's summoning. Archer blinked when he realised it wasn't the usual kind of calling. He figured the world he would land into may need a more subtle approach to cull the humanity, instead of through the brutal violence of a typical Counter Guardian summoning.

He was fine with that. A vacation was always welcomed.

Though, it was a bit puzzling when he heard Alaya's voice. Archer wasn't sure of the exact words, but he swore he heard 'sorry' and 'late'.

And...and a giggle.

Dread filled him.

'Alaya?!' he thought, 'Giggled?!'

Out of nowhere, a dark vortex appeared in his barren world. With a sharp tug, Archer was sucked into it before he could even spew expletives at Alaya.

It was the worst summoning experience he had ever gone through.

A rough squeezing, before -


His sensitive nose was immediately assaulted by all sorts of unknown magical scents, as if the very air was full of mana. His eyelids couldn't open, and Archer felt awfully cold. A blanket covered his body soon, granting him warmth and comfort for him to begin to think.

'...What the - '

Then, his scent hit him.

The ambient mana may have confused his sense, but this particular scent was familiar. A bit different than his own, but unmistakable.

It seemed that the other had noticed as well, because as one…

...they screamed.


There was an invisible blast, blowing Arthur and the MediWitch off their feet. They quickly scrambled up in bewilderment.

"Woah, was that accidental magic?!" Arthur wondered, "...And Molly, another twins?! You didn't tell me!"

For some reason, the twin newborns wailed even more loudly.


Another invisible blast, this time stronger. It even singed Arthur's hair.

Molly Weasly blinked tiredly. She must've heard wrong, because she thought she heard her babies screamed 'Fuck' as one.

She shook her head.

Maybe it was her exhaustion talking.

Author Notes: I don't know if there's any fic out there that features Shirou and Archer being reborn as twins (yes, twins, in case you didn't get it when you read this fic), but I've never seen one. That's quite funny, because they're essentially the same person, only with different life choices and experiences and shits that were thrown at them. Why not twins?

You guys should've figured who Arturia's parents are, and who Shirou and Archer's are. As for Rin's, I'm still conflicted on whether to make her a muggleborn or a half-blood. Making her a Potter is possible, but I find the idea already too common. Suggestions are welcomed :)

If you're wondering whether Ron or Draco are replaced with Shirou&Archer and Arturia respectively, my answer is no. Shirou and Archer would be a year older than Ron and a year younger than Fred and George, so by the time HP cannon starts they'll be in the second year. Arturia would be Draco's older sister (maybe).

I've written the next chapter as well, so I'll just post it together with this one.