Hello! This is my second time making a fanfic. Also Disclaimer! The Fate series and its characters belong to Kinoko Nasu and Demon Slayer belongs to Koyoharu Gotouge. I only own the story and the oc. Now, on to the story!

Whoosh….

In the dark night of November a white mid to large size business jet landed on the runway of Oita airport. Even while the time is still 6 pm the sun has already set. The entire area is lit by the bright concentrated lights from flood lights that lined the runway.

With an hiss from the plane, the larder door of the jet folded down to reveal a stair that was built into the door. After a few moments someone finally decided to step out of the plane. With the distinct sound of shoes against steel, a person decided to step down a flight of stairs that lead to the ground.

"Ah~~ Japan, it's nice to finally be back." said the woman dressed in a purple coat with glee.

"Liz, Sella? You two go on ahead, I'm going to stay here for a bit." said the woman as she looked back towards 2 other women in suits.

"Are you sure about that ma'am? Leaving you here alone might compromise your security." said Sella carrying a black suitcase in her hand.

"Your worries are unnecessary, Sella. My familiar has checked this area, we are perfectly safe." said the woman nonchalantly.

"Then I shall not argue further." said Sella as she turned to leave with Leysritt.

"Sella, be sure to hypnotise the security. We don't want another incident with Liz's battle axe." said the woman the moment she thought of what happened to them last time they went to Japan.

"It shall be done," said Sella without turning back. Entering the door that leads to the passport checking area.

"I wonder how my brother is doing?" said the woman to herself as stares at the sky.

"Well, I better get going." said the Woman as she turned to move in the direction of aides.

"Die Luft ist kühl und es dunkelt, Und ruhig fließt der Rhein~~~"

London Clocktower

Waver velvet otherwise known as Lord El-Melloi Il to the majority of the knock tower is to put it simply tired. For some reason the entire tower seems to have a competition where they could overwork him the most. One moment he's sorting the financial work of the El-Melloi family while simultaneously creating a lesson plan that has to be more efficient than that of the other department all while making sure that it isn't better to a point that it would earn him a Sealing Designations and have Enforcers being sent after him, then the next moment he have to deal have to participate in the Grand Roll with the other 11 lord.

"God… why do I have to do this." groan out Lord El-Melloi Il while drowning is a small mountain of paperwork.

"I'm seriously reconsidering my decision for not shifting the El-Melloi responsibly to Emiya the moment he arrived in the Clocktower. But I have a feeling that even if I do that, Reines will still somehow make it worse for me… then again handing a person who can print out noble phantasm AND has a reality marble is a bad idea." said Lord El-Melloi Il out loud.

Suddenly without warning a blond woman barged through the door, blasting the door off its hinge and into the wall.

"Oh god it's you. What do you want from me, woman! I already did the thing you ask." scream Lord El-Melloi Il in both annoyance and anger as he launches a manuscript towards the woman's face at high speed.

"Oh, brother. Is the Grand Roll really this bad? If I knew you would do this, I would have done this more often. You usually would have just ignored me,but look at you, throwing your own manuscript at me." smile the woman sadistically, while taking the book from the maid that has managed to catch the flying book right in front of the woman's face.

"Fu….Fuck you!" said Lord El-Melloi Il before collapsing face first onto the desk he was on.

"Wait… brother, are you alright? You act like your… oh, I see… " said the woman after discovering the glass shot bottle next to the fallen man.

"Sniff sniff.. Definitely drunk." said the woman after smelling the distinct smell of whisky.

"Trimmau, fetch me the detoxifier." ordered the women.

"I'll be back." said the maid before dissolving into a pool of mercury-like substance, and disappeared.

"You know, this is my first time seeing my brother this intoxicated. I wonder what happened?" muse the woman before she decided to zap her brother with a weak electric spell. Whether it is from the pain or the electrified nerve Lord El-Melloi Il suddenly rocks backward until his back hits the back of his chart.

"Ah! Wonderful, just in time." said the woman as the maid drank the bottle of detoxifier, hand her finger morphed into a needle and jammed the needle into Lord El-Melloi Il's neck.

"AHHHHH!" scream Lord El-Melloi Il in shock as the detoxifier in his bloodstream took effect.

"You're awake?" ask the woman after seeing his reaction.

"Yea… What are you doing here, Reines?" ask Lord El-Melloi Il.

"You see, I was planning on informing you about something before I saw you wasted in your office. Just i was surprised when Lord El-Melloi Il, one of the twelve lords of the clock tower, was found wasted in alcohol due to some paperwork" said Reines, her smile getting wider and wider on Lord El-Melloi Il's realisation that she has gotten more blackmailing materials.

"Sigh~ What do you want?" ask Lord El-Melloi Il, already knowing Reine's usual tactic for getting what she wants.

"Well, you see. I was at the cafeteria during my lunch. I have to say no matter how many times I tried it, the Wagyu Beef Wellington is still always my preferred dish on a monday. Ah there's also…." said Reine, perfectly well aware of the bulging vein on Lord El-Melloi Il forehead.

"Get to the point!" ordered Lord El-Melloi Il. slamming his fist onto the table.

"Right. So I heard that one of the apprentice of the wizard marshal, I believe her name was Toyama…."

"Tohsaka."

"Right her. So I heard that she is going back to Japan for a Holy Grail War Veterans reunion." said Reine.

"And I should care because?" ask Lord El-Melloi Il, his annoyance reaching new heights upon hearing the word 'Holy Grail War'.

"You still don't get it? You! You're a Holy Grail War Veteran." said Reine all while repeatedly poking his chest with her finger.

"So you're telling me that I should go?" asked Waver.

"Yes!" answered Reine.

"I can't." said Waver instantly.

"You can't?" ask Reine.

"You seem to forget that as one of the twelve lords of the clock tower, I have my responsibility both as the head of the Modern Magecraft Theory department as well as the lord of the El-Melloi family. This entire reunion would be nothing but a waste of time" said Waver.

"But it won't," said Reine.

"How? How won't it be a complete waste of time? Explain that to me." ask Waver.

"Well, first, members from all three of the founding family will be confirmed to be there. That includes the Tohsaka, Einzbern as well as the now fallen Matou family. And the Second Magus Killer as well." said Reine.

"Wow, the Second Magus Killer and a Lord of the Clock Tower in the same room. I wonder how that would turn out. Need I remind you that this man's father killed your brother AND destroyed your family crest?" ask Waver sarcastically

"Considering that you're on good terms with him and killed MUCH less than his father, I'll say that you'll be fine," said Reine.

"That still doesn't explain why I would want to go there. I call to meet with Tohsaka anytime I want in the clock tower. I can go to Germany if I want to meet with the Einzberns. The Matous are worthless after Zouken's death, and I want to stay as far away from that 'Enforcer meat grinder waiting to happen' as possible." said Waver.

"Well, too bad for you." smiles Reine sadistically as she pulls out a handwritten letter with a red seal stuck to the bottom.

"What's this… Oh no.." said Waver in fear after he discovered that the seal belonged to the El-Melloi family.

"How did you manage to get the elders to agree to this?!" scream Waver.

"Quite simple really. I just omitted some words, and the elders are suddenly rushing for you to participate in the reunion. And soon you will to." said Reine

"Sigh~ what did you say?" ask Waver.

"Well nothing surprising. I might have leaked that the Holy Grail of fuyuki might have been reconstructed." said Reine.

"WHAT?! We have just taken apart the entire grail system years ago! Why would they want to rebuild it?" Ask Waver in shock.

"Why don't you go ask Tohsaka yourself? I would like to know as well." ask Reine.

"I will, why haven't you asked her yourself? Get your goons to drag her here like what you did to me." ask Waver.

"Sending goons who aren't even enforcer levels to kidnap the First Discipline of the Wizard Marshal, who by the way also have over a decade of experience with the second magic? I might as well send a copy of Twilight to the Eclipse Princess." said Reine.

"They're not that bad." said Waver

"Those two trash the combat arena on a daily basis, that arena is made to survive Enforcer training!" yell out Reine.

"And you deal with clock tower politics on a daily basis, you should be able to handle this." said Waver

"She is your apprentice." said Reine.

"She WAS my apprentice." counter Waver.

"You're on better term with her" said Reine

"Fine, I'll do it myself." said Waver, dragging himself out of the desk and out the doorway.

Pov Rin Tohsaka.

Rin Tohsaka, more commonly known as Zeltrech's apprentice, is very annoyed. She was in her room packing up her stuff when suddenly someone knocked on her door. Why would anyone want to meet her at this time?

Slowly Rin got up close to the door and peeked through the peephole, what she saw surprised her.

Outside the door stood Lord El-Melloi Il, one of the Twelve Lord of the Clocktower. Lord El-Melloi Il is usually never far away from the area around the Modern Magecraft Department, anytime someone wants something they usually go to him. As such it is already surprising to see him at the Mineralogy Department's living quarters, him personally knocking on her door just makes it even more surprising.

"I can see you looking at me through the peephole Tohsaka. Open the door already, I don't have all day." said Lord El-Melloi Il, glaring through the peephole.

Hearing that, she immediately unlocked the chain lock of the door and opened it to reveal the towering lord. His foot tapped impatiently as he waited.

"Can I come in?" ask Lord El-Melloi Il.

"Oh, of course my lord. I didn't expect you there. Come on" answer Rin.

"What brought you here?" ask Rin as Lord El-Melloi Il walks past her.

"I was informed of this Holy Grail War Veterans reunion by one of my associates." answer Lord El-Melloi Il as Rin's eyes widen in surprise.

"Do you wish to participate, my lord?" ask Rin politely.

"Yes, I have deemed that participating in this reunion is beneficial to the interest of the El-Melloi family." answer Lord El-Melloi Il.

"Ah… I see. While I would love for you to participate, there might be a slight problem with that." said Rin.

"Which is?" ask Lord El-Melloi Il.

"This." said Rin, pulling out a slip of paper. On a closer look Lord El-Melloi Il that the slip of paper is in fact an airline ticket.

"The reunion is in a week, and the fastest flight from London to Fuyuki would take a minimum of 12 hour. And I only have one ticket" said Rin.

"Then I'll just buy another one then," said Lord El-Melloi Il.

"You see, the problem with that is that all the planes from London to Fuyuki or Osaka have all been booked to max capacity," said Rin.

"Oh… I guess I will have to think of something then, don't I?" said Lord El-Melloi Il before pulling out a phone from his pocket.

"I'm sorry to say this, but you need to leave. I need to pack up now. I need to be at Heathrow Airport in 3 hour." said Rin as she returned back to packing her stuff.

"I shall take my leave now then." said Lord El-Melloi Il before turning to leave the room and closing it behind him as he went.

"All right, I think that's everything." Smile Rin as she slams the suitcase shut.

"Wait, what if I forgot something? Better check it again." said Rin as she reopened the suitcase and checked everything for the twelfth time this day.

Pov: Japan Osaka

In the city of Osaka stood a building that almost all residents of the city recognize. Towering above most of the skyline stood two interconnected towers that twist around each other. The aesthetic of the tower was further enhanced by its organic plant covered shape that set it apart from its surrounding building. Yggdrasil, or The Tree as called by the locals, serves as the headquarter of the Kariya Corporation.

Suddenly appearing less than 20 years ago, Kariya Corporation became the leading company in the biological engineering field in less than a year due to its constant introduction of revolutionary products. At first it was just some low quality GMO seeds, everyone thought they were going to be brought out by bigger GMO corporations. Then they released something that shook the world. They patent a completely new type of biofuel that is cheaper and more efficient than their fossilised counterpart. This is thought by many to be the start of Kariya corporation's rise to prominence. Just a year ago they finally revealed the true nature of the building in the middle of Osaka. Just as many have suspected, Yggdrasil is in fact alive. The building from main structure to the furniture are almost completely made using organic material, and the twin tower is in fact 2 genetically modified giant trees grown in the shape of a building. Yggdrasil stood as the crown jewel of the Kariya Zaibatsu as well as a shining achievement of the potential of Bioengineering for the people around the world.

"No Shinji, we aren't putting your face on this product." said Hina Tanaka, the current head of the advertisement department.

"Why? Why shouldn't we put my face on this product?" ask Shinji Matou the founder, chairman and CEO of Kariya Corp while sitting in a cross-legged position on a wooden throne-wheelchair hybrid swirling a glass of wine.

"Because we had already put your face on the last product and the product before that!" answer Hina in frustration.

"Ah.. Yes those two products, they sold like hot cakes they did not. How much did those two make us? 350 billion yen in a year if I remember correctly, or is it 400 billion yen? I might need to check back with you on that." said Shinji smugly before taking a sip from the wine.

"We know that the sales are due to things BEHIND the cover," said Hina.

"How can we be so sure about that?" ask Shinji

"Because of this!" answer Hina, taping down the enter key on her laptop. What was projected up onto the wall was a string of customer reviews for the two recent products.

"The fertiliser is good, but please remove the face. It's creepy….. What is this?" ask Shinji disterbed by the comment.

"This is the customer's reaction to seeing your face on the fertiliser." answer Hina.

"H…how? My face, it's the second most beautiful thing in the whole wide world." said Shinji in shock while carcassing his cheek using his spare hand affectionately.

"Sigh… I don't get paid enough for this." said Hina, massaging her nose bridge.

"But I pay you over 50 times what that damned sweatshop paid you 10 years ago." said Shinji.

"At least my old boss doesn't purposely carry around a bottle of wine to drink around people." said Hina.

"That's because he doesn't understand the beauty and awesomeness of drinking wine at work." said Shinji before pouring himself another glass of wine.

"It doesn't make you look awesome, it just makes you look like a prick," said Hina.

"I get that a lot. But it doesn't matter! I know a person once, he was a prick order of magnitude more than me. But that didn't stop people from liking him." said Shinji.

"Oh god this is another rant about your past isn't it?" ask Hina.

"What? No. I'm just saying that being a prick is good." answer Shinji

"Like covering up your inferiority complex?" ask Hina

"That too. But not anymore. Look, I have perfected myself." said shinji as his hand as a layer of dark blue gas covered his arm and morphed his arm into a claw-like gauntlet made of some type of rainbow-sheened material. .

"What is it this time? Narce?" ask Hina.

"Yes this gauntlet is made using Narce also called the mother of pearl. This thing would have no problem stopping a barrage of 50 calibre machine guns." said Shinji

" You said that we don't make weapons. Directly to the Minister of Defense himself." said Hina.

"We aren't selling weapons. I'm just making this for fun." said Shinji.

"Yes sure… What are you gonna do next? Create an army of supersoldiers?" ask Hina sarcastically.

"..."

"Shinji, that was a warning not a suggestion. Don't do it." said Hina.

"..."

"Sigh~ shouldn't you be somewhere?" ask Hina

"Somewhere? What do you mean?" ask Shinji.

"I thought that you were going to meet with your sister or something." answer Hina.

"Oh…. OH CRAP! I gotta go!" said Shinji before jumping up, growing another set arm out of his back,holding up his wine set, picked up his throne-chair and ran away in speed no human should be capable of.

"I never know how he did that.." mutters out Hina as she witnesses the way her boss constantly gives basic biology the finger.

Matou shinji ran. He weaves through the hallways and stairs with superhuman speed, heading towards the top of the tower. Soon he was met with a wall, a plane and a simple wall.

After taping the wall in a particular pattern and order, a rumbling sound was heard. The original started to bend and morph into a green circular twin door, its door frame made entirely out of thick wooden stems with a few leaf branches dotting its top and sides.

After checking that he wasn't being followed, Shinji pushed open the door with both of his hands and entered, the door fading back into the wall just a few seconds later.

Hidden behind the wall, Shinji has finally entered his lab. At a glance, the design of the lab is the same as the rest of the building. The room is still covered in white hydroxyapatite crystallite plates, and the room is still illuminated by the blue glow of bioluminescence lights around the room. What set things out however, is the large pillar that stood in the center of the room.

With bated breath, Shinji walked up to the monitor that was installed on the side and looked into it.

"YESSSS!" cheer Shinji as the number 100% was shown on the monitor in bright flashing yellow.

"Finally, it worked! And just in time for the reunion. I gotta tell Illya that our plan worked." said Shinji in glee and he proceeded to pull out a smartphone from his lab coat.

"With this, I will finally give back to Sakura what our grandfather took from her. Sakura and Shirou are going to be so happy when they hear this. '' said Shinji before tapping into the landline installed on a table nearby.

"Tanaka, get me a class B Organ Transporter and the fastest helicopter you can find." said Shinji

"..."

"Yes, bring the Organ Transporter to my lab and the helicopter to helipad Mu. Also make sure there's enough space to store a class 5 surgery kit." said Shinji.

"All right, calculating the trip to Fuyuki, the surgery and the Recovery time we should have enough time for the grand surprise at the reunion," said Shinji, staring at his calendar.

Knock knock….

A light knock was heard from the wall where the entrance to the lab used to be, causing Shinji to turn around with a wide smile.

"And just in time!"

Chapter end

This is the first part of the prologue of this story. I hope you guys like it. If you have any questions feel free to comment below.