[CHAPTER 01]

-Welcome to A.C.D. : Alpha Omega Zero Project-

A vast room full of modern technology decorated with sophisticated machinery, this is the place of what one might call as the epitome of both science and magic. In the center of the room, there lies a strange-looking machine with glowing blue crystal as the core of it. Not to mention, the core is surrounded by pillar of azure light which certainly encaptivates anyone who puts his sight on it.

This place, is no other than the secret part of the main headquarter of [Aleta Crvena Dzvezda] abbreviated as A.C.D. for short, a secret ancient organization which protects the balance of the world from the shadow. One might question the morality and how the people of A.C.D. get the work done. After all, there is neither good nor evil in balancing the world. Wiping out an entire population of humans might be a daily routine if it is necessary to do so.

"…"

There, a man with blond ponytailed hair simply shrugs and heaves a sigh.

"What the heck…!?" Ron is so exasperated that his shout echoes through the entirety of this highly modern hall.

On the other hand, Tohno Shiki simply twitches his eyes in disbelief. Who would not? After all of the parting and farewell words, he ends up in an outlandish place with Ron for no apparent reason.

It is not even necessary to state the obvious that Emiya Shirou, Tohsaka Rin, Saber, and Sion Eltnam Atlasia are even dragged along somehow. As if not being comedic enough, they are in the exactly similar position facing towards the eccentric trio who happen to be also in the exact same position from when they bid a farewell several minutes ago.

"*Sigh, what in the world just happened…" Tohsaka Rin tries to assess the situation she is currently in. After all of the mess and troubles she had to undergone in Misaki, she intends to come back to Fuyuki. However, her plan to come home is obliterated into oblivion.

"Seth, is this—a" Ken, who has been silent up until now, finally speaks up in a rather serious tone unlike his 'usual' bubbly cute persona.

"It is exactly as what you have thought, XIII." Seth, on the other hand, replies in his stern facade.

"Welcome to [Epiclesis], my honourable guests!" A voice of young boy reverberates.

The short stature of this boy matches his medium length grayish-black hair and eye colour. His fashion sense seems to be rather peculiar with pure white long coat with sleeves longer than his own arms. The boy's carefreeness and energetic presence are even several times higher than what Ken normally does.

"As I expected, you are indeed involved in this coincidence, Gray." Seth's sharp eyes imply his annoyance. This boy before him or rather this man actually is the leader of A.C.D., in the other words, he is Seth's direct superior.

"Sharp as always, Commander! Welcome home, Seth! Did you miss me so much, did you? Hehehe…" Gray laughs mischievously like a spoiled child.

"That kid is the leader of A.C.D.? No wonder all of the members are batshit crazy, geez." Ron whistles to emphasise his insult.

"Gray…"

"It's a been while there, Number XIII—or perhaps Ex-Number III, I should say..." Gray flashes a smile with contained murderous intent towards Ken, his former subordinate.

"CAN ANYONE PLEASE EXPLAIN TO ME WHERE THE HELL I AM NOW!?"

Tohsaka Rin who has been agitated with the nonsensical greeting of Gray finally lashes out in anger.

"C—calm down, okay Tohsaka…"

"R—Rin"

Both Saber and Emiya Shirou try to calm Tohsaka Rin's temperament.

"Pardon me, young lady. Let me try to explain the situation in a moment." For an instant moment, Gray's cheerful demeanor vanishes.

"I apologise for interrupting you first, Gray. What is this place? I never recall to ever visit this place in the first place."

Seth's inquisition is natural. Even if he is the second-in-command of A.C.D. after Gray and he knows the layout of the main headquarter, Seth never even once comes to this place. Forget about coming to this place, he does not even know the existence of this hidden chamber in the first place.

"This is [Epiclesis], the last defensive line of this world, Commander. Naturally speaking, there are only two people in this world who know the existence of this place including me. Our main objective is to—" Gray suddenly turns his gaze into the silent girl who keeps on staring at a certain 'aspect' of this room.

"Please forgive my impolite manner. Gray-san, I assume? Let me introduce myself first, I am Sion Eltnam Atlasia, an alchemist of Atlas." Sion who has been observing the azure light pillar in the center of this room finally says something.

"It is a pleasure to meet with you, Sion-san. I wonder why you keep on staring at my splendid possession though."

"That is a form of alchemy, isn't it? An Atlas kind of alchemy… although I am confident enough to say that you modify something in the process."

"Not quite the right guess, Sion-chan, hehehe. True enough that I have adopted the Atlas Alchemy for some reasons, however… [Epiclesis], is not merely created through alchemy. It is an epitome of mankind's highest achievement in combining modern technology, sorcery, and alchemy. This is a device capable of interacting with the other worlds."

"I see, I shall leave it at that then… Please continue what you want to say previously." Sion halts her inquiry and curiosity. She thinks it is wiser for her to have a clear explanation first in this case.

"Very well, let me reiterate and state this clearly. Welcome to [Epiclesis], my honourable guests. I have specially summoned you here to form an alliance with all of you. My name is Gray, leader of [Aleta Crvena Dzvezda], an organization specially formed to protect the balance of this world. Obviously, what I mean by 'this world' is the world all of you are currently in and not your own home world."

"Hold on a minute, you are telling us to save your own home world, aren't you? That's just absurd!"

"Now Tohsaka, let's hear out what this guy wants to say first. It's very rude to interrupt people when they are talking."

"I agree on this matter with Shirou, Rin. We should— "

"Well then, Emiya-kun and Saber, we are not a non-profit social worker! It is my policy to have something as a compensation when I have to work for someone, especially with that shady looking boy."

"T—Tohsaka…" Emiya Shirou simply shrugs. He knows best how unyielding Tohsaka Rin can be when she decides to do something her way.

"Very well then, Gray-san, I presume? I guess it's only natural for me to introduce myself first. I am Tohsaka Rin, the current head of Tohsaka family. As for my two companions here… These two are Emiya-kun and Saber."

Emiya Shirou and Saber slightly bow down just like what Japanese people do when they meet people as a form of polite greeting. On the other hand, Ken who has been in a rather unpleasant mood from earlier, wanders around the room looking at the wonder of modern looking technology and devices in the entire room. On top of that strange looking azure pillar of light in the center of the room, there are various monitors and high-tech computers around the room complete with various suspicious buttons. Amongst the sophistry, there is this rather standout looking red button on a computer-like machine located near the azure pillar of light. As Ken walks around, he observes the whole scenery in amazement.

"Well Number XIII, feel free to take a quick look around. Even as a former member of my precious elite squad, [15 Black Guardians], I grant a permission. Well, moving on to our main topic. Do not worry, Tohsaka-san, Emiya-san, and Saber-san, I am extremely positive that you will lend your hands for me. Oh, that also includes Sion-chan and that eyeglasses boy over there as well…"

"Hoo—, you seem very confident, don't you? I wonder what kind of 'compensation' that you will give to us in return."

Gray's innocent-like façade changes at that very moment, grinning in a rather sadistic manner. His previous carefree attitude has been replaced with his true nature as the leader of A.C.D.

"Very well done, Tohsaka-san. Before asking for compensation, let me assess the current situation which all of us are currently in. First, my world—I mean the world we are currently in is the home for my beloved Commander, Number XIII, and that greenhead over there. Our world is actually a branch of a bigger world known as the 'Tree World', [Yggdrasil]. There are 9 main branches connected to [Yggdrasil] which implies there are 9 different worlds connected to it. Each branch has its own occupants, for example, this branch is where humans live. Each branch functions to support the life of [Yggdrasil] and of course there is no need to mention that the death of our beloved 'Tree' results in the destruction of the world. The problem is, there exists this mythical creature Niddhogr who gnaws on the root of [Yggdrasil]. Normally, Niddhogr-chan is not vicious enough but a certain stupid person provokes it. Should Niddhogr-chan fully awakens, I am pretty sure that—"

"The end of your world is going to come, isn't it?"

"Correct, Sion-chan! However, that is not the end of the story. This bad guy is really really messed up in the head you know! So messed up that his stupidity is at least one million times worse than my own stupidity! Hahaha…"

"Your point?"

"Oh, let's say if this stupid guy is out of 'work' due to the destruction of my world, what do you think will happen next? Of course, I needn't to say that the monster which appeared in Misaki City and the incident related to it is not related to this guy…"

At that instance, Tohsaka Rin and Sion Eltnam Atlasia realise the grave dangers. What Gray tries to convey is the fact that there is no need for him to grant any form of compensation. After all, should he fail to protect his home world, the next target will be their own home world. Obviously, they survived and managed to avoid further damage in Misaki City because of the help of the trio eccentric. It is just not right for both Tohsaka Rin and Sion Eltnam Atlasia in this situation to not repay the debt.

"Hold on a second, that thing in Misaki City was coming from this world? That was just insane! Look, I am not a saint and I know my own limits. There is no way for me to help because— ", Tohno Shiki's words are put into a halt.

"Do not worry, I have prepared special presents for both of you and Emiya-san. Rather, I have prepared everything in advance for all of you. Furthermore, you are not the only one here, I have some more guests or perhaps extra-helpers to arrive here soon enough. First thing first though, I have to remind all of you to NOT touch anything in this room, okay? I am pretty much scary when I am mad, hehehe… Especially that red button in—"

'the middle of this room', the phrase does not even finish yet and someone has already pushed the button.

"D—do you mean this button, Gray?"

At a single push, the button has been pressed. Gray, who has not paid any attention closely to Ken, twitches his eyes in exasperation.

"That chicken-head finally returns to his idiotic self, huh? What a pain…" Ron heaves a sigh whereas Seth who stands next to him only nods in agreement silently.

"Commencing initial sequence. Surveilling fluctuation in spacetime coordinate, checked. Proceeding to the next sequence, calling forth— "
A sudden machine-like voice echoes as the azure light pillar glows bright. Everyone in this room does not even flinch for a second.

After a wave of golden light emanating from the azure pillar of light, a heavenly figure materializes as the blinding light silently disappears into nothingness.

There, a holy maiden stands before them, holding a grandiose flag and silently looking straight at them. The maiden, wearing elegant silver armor, exudes the gracefulness of The Lord from above, as if being a direct messenger of God. Perhaps, she is indeed the true messenger of God.

"Servant Ruler, ready at your command! I have come forth to fulfill my duty. Tell me, which one of you is my Master?"

"Y—you've got to be kidding me, right… Aha— ", Tohsaka Rin has not even blinked in awe.

"A—another servant?!" Saber, who has been silently following the conversation up until now, is also amazed by the appearance of the mysterious servant before her.

"Thank goodness, it is still according to my plan—…" Gray heaves a sigh of relief.

And thus, the main casts have arrived in the stage. Let the journey begin.

A long-narrowed passage of emptiness extends as far as the eyes can see. The wall of the passage itself is inscribed with various ancient language scribbles and runes, signifying both secrecy and simplicity. The size of the passage itself is enough for three average men to stand side by side and yet the long straight path of the passage which seems to be endless creates an illusion of another worldly place connecting to another different realm.

There, two men are walking casually side by side or perhaps it is more suitable to say a boy-like figure and a blond ponytailed hair man.

"I still did not believe for such coincidence to really occur. Perhaps the Gods are in our side now. Don't you think so, Commander?" The boy-like figure starts a conversation after several minutes of silence.

"I believe it is one of your habits to pretend something as if being a coincidence when both of us know you can alter the result at will, Gray. Also, we both know that Gods are no longer capable of interfering directly in the present era."

"Ahaha— Is that so? I did not expect for Jeanne d'Arc to be summoned though. Well, it's not like I did anything significant, Seth. It was at least going to the direction where I wanted to." Gray chuckles mischievously. "But still—, I did not expect to see Number XIII to change drastically. It was so shocking, wasn't it?"

"Indeed. However, it still does not change the fact that he did leave A.C.D."

"Well, it was not that bad, anyway Commander… There is something I need to show you."

After an incessant straight walk in the passage, both Gray and Seth finally arrive in a weird chamber. In the center of the chamber, there lies another sophisticated apparatus with glowing green crystal resting inside of it. The size of the chamber is neither small nor large. Furthermore, numerous magical crests and inscriptions fill in the place in a rather peculiar manner unfitting to the touch of slightly modern-looking green crystal in the center.

"T—this is the— "

"[The Heart of Ymir], an ancient artifact from the Age of the Gods. You might have been my commander for a long time, Seth. However, there are still a lot of things you do not know lying around in our beloved main headquarter here." Another devilish chuckling laughter of Gray resounds.

"I see, I believe it is natural to use such a countermeasure given the dire situations we are currently in." Seth calmly replies knowing the thought of what his superior trying to do. "However, do you truly believe such countermeasure is necessary, Gray? We are talking about one of the most precious treasures in our world here. No, the word precious does not even fit the description for this— "

"There is no need for you to worry, Seth. As the survivor of the 'The Great Battle of The Lost Continent', you do understand our current situations better. Apocalypse, Ragnarok, Doom's Day… Humans—No, the world has undergone countless times of unending conflicts. It is our duty as the protector of balance to prevent these things." After the sudden cut off, Gray for the first time after Seth's return to this world, finally shows his true nature as the current leader of A.C.D.

"I see, I shall not doubt your judgment then. However, there is still one more thing which I need to inquire, Gray."

"Well, let me hear your last inquiry then, my dear Commander."

"Why do you allow outsiders to intervene with the problems of our own world? To the extent of my knowledge, there is a silent agreement between [Miracle Users] to not allow— "

"Other people from different multiverse coming in to our world? Yes, under normal circumstances, I also would not want to do it this way. Even I do not want to mess with that perverted Oldman to a certain extent. However, Seth, our current opponents pose threats in the level of inter-multiverse scale."

A multiverse, a model of multiple universes as a part of existing reality. Modern science has advanced far enough to propose such a theory. Nevertheless, the implication of inter-multiverse from what Gray trying to explain is on the entirely different level. Imagine a single of page on a book is a single layer of timeline of one world. Then, a book composed of infinitely many possible timelines is only worth one universe. By collecting another yet infinitely many books inside a library, one would arrive in the concept of a single multiverse. At the very least, the latest theories of modern physics have successfully laid a foundation to explain this phenomenon. However, there is no rule saying that there exists only one multiverse. Continuing our analogy, there exist infinitely many libraries with different set of rules. Hence, there must exist infinitely many multiverses with different set of natural laws.

"Inter-multiverse scale— Who in this world is capable of pulling such a threat? Not even the [Chernoe Solntse] dares to conduct such a thing."

"Kiritsuki Yaminaka." Gray mutters the words and at that very instant moment, Seth's calm demeanor slightly changes. "Obviously you still remember how he almost brought a second Ragnarok into our world approximately a year ago, don't you Seth? He did cause a lot of problems and even the [The World Magic Syndicate] and [The Holy Church] were forced to form an alliance."

"I see, if he is the perpetrator of our current situations, then our current countermeasure is unmistakably compulsory."

"Very well then, Commander… With this, I hereby declare the greatest war in history of mankind."

Thus, the conversation between Gray and his commander Seth ends with a devilish giggle and silent gaze toward the [The Heart of Ymir].

[Temple of Hyalos]

An otherworldly place beyond what words of mortals are able to describe, full of luminescent quartz decorating the entire interior of this place. The floor is translucent and the ceiling looks like a beautiful starry night sky. There, in the center of the room, lies a magical crest with glowing quartz.

Three unusual men are encircling the magical crest. The first one is no other than Kotomine Kirei, the heretic priest who miraculously survives and thrives the previous catastrophe in Misaki City. The second man is no other than the King of Heroes, Gilgamesh, with his majestic golden armor standing next to Kotomine Kirei. The third man, a somewhat handsome man with a rather mixture of Oriental and Caucasian façade, is no other than Kiritsuki Yaminaka. This man alone wears an eccentric black cape with hood to hide his rather handsome face.

"Well, well…. I never know people can cheat on death rather easily. Perhaps, I lack knowledge in the customs of humans in the other world" Kotomine Kirei starts the conversation with a blatant sarcastic tone. His reaction is only natural as he does not expect that Kiritsuki Yaminaka's plan works smoothly enough.

"Everything can be done with a proper setup, Father." Kiritsuki Yaminaka only smiles as a reply to Kotomine Kirei's sarcasm. "Very well then, shall we proceed to the summoning ritual? We are now able to proceed to our real plan without reserve." After a brief silence, he flicks his hand and at that instance, the magical crest begins to glow.

Surging waves of magical energy are dancing wildly and several pillars of light appear on the ground inside this ethereal place with various colours.

The first pillar of light coloured in red finally ceases to exist. In exchange of the previous pillar of light, a calm yet dangerous looking warrior emerges. He takes several steps forward and then halts them abruptly. "Grand Servant Lancer, Karna, at your service."

Following the first pillar of light, two more warriors emerge from a rather white coloured pillar of light and green coloured pillar of light correspondingly. The first warrior appears to be a woman dressed in white armory wielding a rainbow-like sword on her hand whereas the second warrior appears to be a man with a huge sword on his back.

"Grand Servant Destroyer, Altera, The Great King of Destruction."

"Grand Servant Saber, Siegfried, Slayer of Dragon Fafnir. I am here to serve you."

After three servants of the highest quality being summoned, various pillars of light emerge on the ground again and naturally have varying degree of colours such as violet and black.

"Grand Servant Pharaoh, Ozymandias, The King of Kings."

"Grand Servant Conqueror, Alexander, The King of Conquerors."

"Grand Servant Avenger, Angra Mainyu, All Evil in the World."

Six new servants in total appear before Kotomine Kirei, Kiritsuki Yaminaka, and the King of Heroes, Gilgamesh. All of them have been summoned at their best possible capabilities without any restrain.

"My, my, I never know you can summon a servant in this kind of way… I should praise your abilities in hacking through a magical system even in the complexity of Holy Grail."

"Enough with the pleasantries, Kotomine. This is interesting, interesting! For a king as great as me, you have brought me an exciting experience, Yaminaka!" Finally, the King of Heroes, after declaring his utmost satisfaction, gazes around the other servants. "Now hear this, all of you mighty warriors and kings in history of mankind! Rejoice and behold to the true magnificence of the King of Heroes! Grand Servant Gilgamesh, Gilgamesh, the King of Heroes! I shall hereby declare! Let us begin this banquet of the highest quality!"

"Very well, my King, let this banquet begin, shall we?" Kiritsuki Yaminaka sneers with the utmost joy on his face.