Hello, everybody! This is X the Reaper, and I've finally found some true inspiration for a story. I promise I will do my best to grant all of you viewers a worthy show.

This is a Fate/Stay Night crossover fic, going with the usual idea of different Servants from other series appearing. Note, some people will be staying the same.

Disclaimer: Fate/Stay Night and all series mentioned in this story are all owned by their respective owners. Also, thanks to The Infamous Man for providing the idea for the fic. You're awesome, TIM. Also, thanks to Sentinel07 for being the one who inspired me to write this fic. Thanks, man.

Now then, let us begin!

Angra Mainyu. The Source of All the World's Evil, former Avenger of the Third Holy Grail War, and currently the corrupted conscience of said Grail, was... bored. To be fair, being stuck in a chalice with nothing to do would do that to anyone, but seriously, it was BORED and had been for 60 years. Well, at least the Fourth War would be starting in a few years. It had already checked the list for the new servants, and it honestly had mixed feelings on the subject.

On one hand, it had Saber. Brave, chivalrous, strong and a girl to boot. Archer was an arrogant, glamourous douchebag, but he had enough power to easily back it all up. Rider, a man whose charisma stole the attention of everyone in the scene, and a badass among badasses for extra measure. To top it all off, all of them were kings. It felt rather certain about these three being in here.

The others... not so much.

To be fair, they were powerful, but they just didn't interest Angra Mainyu as much. Lancer, damn good with spears, but a little too concerned with his honor and "fairness." There was enough of that in Saber. Berserker, impressive backstory filled with betrayal and interesting relation to Saber, but a growling lunatic whose only modes were "rest" and "kill," just like every other Berserker. Assassin, not even worth mentioning. The guy barely had any backstory and no personality. Caster,... crazy as hell, and just as creepy. Those eyes looked like something that belonged on a fish.

Yes, it wanted to change up the system a little. After all, the Throne of Heroes had no shortage of unique heroes to use.

After some searching, especially in the categories marked "Alternate Universes," Angra Mainyu found four new Servants to replace the Lancer, Berserker, Assassin, and Caster classes, but it still felt it could use a little more... interesting characters.

"You know what? Fuck it. Let's bend the rules a little bit more." So, it exerted even more power and found another "candidate" as Avenger.

Yes, even after being killed as Avenger, the corrupted conscience of the Grail still had a soft spot for its personal class.

Eight Servants. Yes, this would keep it entertained for a long time. It would be interesting to see how the Kings of Knights, Heroes, and Conquerors would fair against these warriors.

Plus, it would be fun to throw the participants for a loop.

Oh, one of candidates was attempting to summon his Servant. Ah, yes. Kirei Kotomine, the master of Assassin. How would he react to his new Servant?

No use changing anything now. The Grail "relaxed" and decided to watch the show.

Within an abandoned warehouse in Fuyuki City (Three Weeks before the Holy Grail War)

Kirei Kotomine, one of seven Masters of the Fourth Holy Grail War and a former Executor of the Church, stood in front of the summoning circle. He was nervous, and rightly so. He was about to enter a war of Magi, and even his time as an Executor had not prepared him for this. Even now, he still did not understand the reason he bore the red marks, the Command Seals that marked him as a Master in the War.

Kirei was not a normal man. He had been born with a sort of emptiness and nothing he had ever done had filled it. In his teenage years, he had done everything possible to fill that hole. He had performed in multiple different fields and excelled in them all, but he never felt that sense of accomplishment that came with a job well done. He even married a beautiful woman who would likely die in a few years, just to see if love would fill the pit. He tried to love her, care for her, and even had a daughter with her with her to solidify his commitment. However, he could never truly fill that abyss, and he confessed those feelings to his wife, telling her that no matter what he could not truly love her and he felt no compassion for anyone, not even himself. She performed suicide later that night, but it was not out of sorrow, as she died with a peaceful smile on her face. She did it so that he would be able to feel compassion, so that he would know he feels just like anyone else does. She wanted him to be happy by helping him find his answer through her own death. And indeed, he did feel sadness, but not because she died.

He was sad because he didn't see her die, didn't kill her with his own hands.

That thought horrified him beyond anything else. Immediately, he gave his daughter, Caren, away to be raised by relatives. He didn't look back, even when she cried for him. He couldn't and wouldn't raise her, not if he felt like that...

Three years before, the Command Seals had appeared on his hands, and his father, Risei Kotomine, had taken him to see Tokiomi Tohsaka, a Magus. The Tohsaka house had long held a good relationship with the Church, and Risei knew Tokiomi's grandfather. Tokiomi explained what the Seals are; they were proof of the Holy Grail's decision to choose a Magus as one the seven Masters in the Holy Grail War.

No, not the legendary cup of Christ used by Jesus at the Last Supper, but a wish-granting artifact of the same name. Every sixty years, the Grail would chose seven Masters to fight in a battle to the death. The winner of this contest would receive a single wish, be it selfless or selfish.

The Grail was made by the combined efforts of the Tohsaka, Matou, and von Einzbern houses for a single purpose: To reach Akasha, or the root of all knowledge. While the other two had forgotten their purpose, the Tohsaka house still sought that dream. Risei had brought Kirei to Tokiomi for a reason, to form an alliance with him and secure the Holy Grail, the reasoning being that their wish wouldn't cause untold destruction to the world, and they could trust Tokiomi, unlike the other Masters.

Kirei himself didn't have a wish, or if he did, even he wasn't aware of it. He accepted Tokiomi's request, and for three years he trained to learn the ways of a Magus under him. Now, as he stood ready to chant the incantation to summon the Servant, once again the question from before rose in his mind.

"Why was I chosen? I have no wish for the Grail, so why would it choose me?" True, he sought some answer as to why he was the way he was, but other than that, he had no desire for the prize.

"Regardless, it is time." Kirei shook those thoughts away and began the chant.

"Silver and iron to the origin. Gem and the archduke of contracts to the cornerstone. The ancestor is my great master Schweinorg.

The alighted wind becomes a wall. The gates in the four directions close, coming from the crown, the three-forked road that leads to the kingdom circulate.

Shut (fill). Shut (fill). Shut (fill). Shut (fill). Shut (fill).

Repeat every five times.

Simply, shatter once filled.

―――― I announce.

Your self is under me, my fate(doom) is in your sword.

In accordance with the resort of the Holy Grail, if you abide by this feeling, this reason, then answer.

Here is my oath. I am the one who becomes all the good of the world of the dead, I am the one who lays out all the evil of the world of the dead.

You, seven heavens clad in three words of power, arrive from the ring of deterrence, O keeper of the balance ―――!"

A bright flash of light filled the room, almost knocking Kirei off his feet. When the light died, he got a good look at his Servant. Immediately, he realized something was wrong.

When he prepared the summoning circle, he used the shattered remains of the skull mask of Hassan-i-Sabbah as a catalyst for the summoning. He wasn't entirely certain what to expect, but he knew from just a glance that this wasn't the 'Old Man of the Mountain.'

The figure standing before him had spiky, short black hair. He wore a black cloak with red clouds that covered his entire body. Underneath, where the cloak was opened, he wore a black long-sleeve top that also covered his neck and chin, a pair of black gloves, and a pair of dark-coloured pants with sandals on his feet. As for his face, Kirei could not tell, as it was completely covered by an orange mask with a swirl pattern that only showed his right eye.

The Servant simply stood there for a moment, and then looking towards Kirei, he spoke.

"I am the Servant, Assassin. Now tell me, are you my Master?" He asked with a serious, emotionless tone.

Kirei was silent, then he lifted his arm, showing his Command Seals. "Yes, I am."

The servant nodded. "The contract is complete. Now, we should leave this place and return to your base of operations."

Kirei got up and looked at Assassin. He was still surprised about his new Servant, but he got what he needed. Surely, things couldn't go anymore wrong, right?

Oh, if only he knew.

One Week Later (Basement of the Tohsaka Manor)

Tokiomi was happy. When Kirei had contacted him and told him what had happened during the summoning, he was worried. Kirei had performed the summoning flawlessly and even used a catalyst. So why had he received a different Servant? Regardless, Assassin still had the abilities necessary to perform their original plan. All Tokiomi had to do was summon the King of Heroes, Gilgamesh, and everything would be back on track.

Still, he took care to double-check the summoning circle and mentally recited the incantation twice before beginning. It wouldn't hurt to take precautions. Even so, he successfully summoned the King of Heroes, and for that, he was grateful.

The golden armored young man looked towards Tokiomi and spoke, "I am the Servant Archer. Are you my Master?" Even though it was a question, it was spoken with the authority of a king upon his subjects.

Tokiomi bowed his head and placed a hand over his heart. "I am indeed, King of Heroes." He spoke as a lesser does to his lord.

Archer smiled. "Very well, the contract is complete." His red eyes were filled with amusement.

Tokiomi smiled. Yes, everything was going according to plan.

Some could not say the same.

Elsewhere (Hotel Room)

Kayneth Archibald El-Melloi looked at his Servant with a confused scowl on his face, while his fiancé, Sola-Ui, was watching with a hand over her mouth and surprise in her eyes. He couldn't blame her, honestly. His original catalyst, a remnant of the cape that the legendary Alexander the Great had worn, had been stolen from him. He had, however, taken precautions in the event that one of his many rivals at the Clock Tower would steal it. His backup catalyst, the remnants of the mystical swords Moralltach and Beagalltach, would allow him to summon Diarmuid Ua Dauibhne, or Diarmuid of the Love Spot. He performed the ritual perfectly, the catalyst was the real deal. So why did he not summon Diarmuid, but a giant?

The Servant was huge, so that even kneeling with his head bowed he came to Kayneth's height. Kayneth had to guess he was at least three times the size of an average person. He wore a black bandanna around his head and adorned with a white captain's coat which hung loosely from his broad shoulders and bore a pirate symbol. He was bare-chested, showing off three scars across it, and wore light, loose pants tucked inside his large black boots, and a dark sash around his waist. He was surprisingly well-proportioned, and his entire body seemed to be pure muscle, sinew, and bone. Even more impressive, he seemed to be in the later years of his life, sixties if Kayneth had to guess. The most impressive thing about him, however, was the MASSIVE crescent-shaped mustache that adorned his face. It was pure white, and it looked like he could cut someone with it.

Completing the picture, the Servant was holding a massive bisento, even taller than he was, in his right hand. The weapon consisted of a red and yellow striped pole, ending in a spherical edge, and a curved, large blade attached to the pole via a golden part, decorated by what looked like a sea snake, with a thin part of it protruding on the blade itself. That alone was enough confirmation of what Servant class he was.

Still kneeling, the Servant spoke in a strong, loud voice. "It is obvious from your expressions that I am not the Heroic Spirit that you expected. However, I assure you, I am of the Lancer class of Servant. Which of you is my Master?"

Kayneth finally found it in him to speak. "I-I am." He then spoke in anger and slight fear. "Answer me, where is Diarmuid!?"

"Kayneth." Sola-Ui spoke softly, stopping Kayneth and then turning to the Lancer. "Forgive him, but yes, he is your Master. He was just shocked at your appearance. I will be providing you with additional Prana for the war, but could you please tell us why Diarmuid wasn't summoned?"

The Servant rose from his kneeling position, and looked down into Sola-Ui's eyes. His face was long, and while it was ploughed because of advanced age with many wrinkles around his eyes, it was not unkind, and his eyes were filled with a sort of fatherly love. "I do not know what became of this 'Diarmuid,' but I can promise I did nothing to him."

"Regardless, now my original strategy is ruined! I did not join the War to constantly be thrown into unexpected circumstances!" Kayneth yelled. He was angry at how fate seemed to constantly interfering with his plans, and briefly considered 'blowing off steam' with Volumen Hydragyrum. "I might as well..."

"Kayneth!" Sola-Ui yelled, stopping his tirade. "We now have a Servant and a powerful one by the looks of it! Obviously, this man did impressive things in life to be placed on the Throne of Heroes, so at least be willing to give him a chance!"

Kayneth was silent, then he simply turned away. "Fine. I'm going to go and get some rest. We have a big day ahead of us tomorrow." So saying, he walked to his room.

Sola-Ui turned to look at Lancer, who had been silent through the whole thing. "I'm sorry, but please forgive him. Oh yes, is there anything you would like?"

Lancer turned and fixed her with a warm, fatherly smile. "Yes, if you would be so kind as to tell me where I could find some wine, that would be great." He was still very large, so he actually had to stoop in order to make sure he didn't hit his head on the ceiling.

Sola-Ui turned and prepared to head to her own room. "Simply call the front desk and ask them to send a bottle up. I do hope, however, you will fight your best in the Holy Grail War, Lancer."

Lancer simply laughed, "Gu ra ra ra ra ha ha ha! I will, little missy!"

Sola-Ui thought about whether or not to reprimand him about that, but she decided not to. It was more of an affectionate nickname than an insult.

"Still, I wonder what type of life a man like him lead, in order to ascend to the Throne of Heroes?"

Oh, she had no idea.

One Day Before the Holy Grail War (Matou House)

"Well Kariya, I admit I'm impressed. The Holy Grail truly recognized you as a Master. It would appear you have some talent after all," Zouken Matou spoke as he looked down on his 'son', a creepy grin on his face.

Kariya Matou was silent. His white hair stood out despite his obvious youth, and the left side of face and body pulsed with the worms inside of him.

"However, I'd only give you a month before the worms completely kill you."

Kariya looked at the inhuman bastard head of the Matou house. If it was up to him, he never would have been here in the first place. He had left his godforsaken family, never to return. Until the day he learned that Sakura, the daughter of the woman he loved but could never have, not if she would suffer the inhuman 'training' that all Matou mages had to go through, had been given to the Matou house to be raised as an heir. She had been tortured, violated, by the worms used in the Matou house magecraft. To save her, Kariya had made a deal with Zouken, that decrepit vampire worm. In exchange for undergoing the Matou training, the very training that was the reason he severed all ties to his family, and winning the Holy Grail for Zouken, Sakura would be freed.

He would rescue her from this hell, before her young, kind soul was broken beyond repair. He just had to win the damned Grail. Then he could help her recover, and she, him, her sister Rin, and their mother and his love Aoi, could play in the park like they use to. In a time where everything was simple.

Even if he only had a month to live after the War, he would live it to the fullest.

"A month's more than enough time," Kariya gritted his teeth as he spoke. Damn these worms.

Zouken simply chuckled. "Well, in honor of this momentous occasion, I have two presents for you." He gestured to the pre-prepared summoning circle behind him.

"The first, a piece of armor from one of the Knights of the Round Table." Sure enough, in the center of the circle was a rusted piece of armor that may have been pure black in its prime.

Zouken pulled out a sheet of paper, "And the second is a way for your Servant to make up for its obvious substandard strength for being summoned by a weak Magus like yourself."

Kariya took the paper and looked at it. On it was the incantation required to summon a Servant, but it had two more lines added on the end. "And what the hell is this supposed to do?"

"This will imbue your Servant with the ability Mad Enhancement, summoning it under the Berserker class. It will trade their sanity for extra power."

Kariya was silent. He had researched the seven classes, and he knew that while the Berserker class was undoubtedly the strongest Servant, it was also the most uncontrollable and cost the most Prana to maintain. Summoning one would give him the edge in power, but the Prana consumption alone would probably kill him if he wasn't careful. At the very least, it would lessen his remaining time. If it gave him an edge, however, he would live with the consequences.

"Fine."

Zouken smiled. God, how he wanted to wipe that worm off the planet.

"Then let us begin."

Kariya stood in front of the circle, clenched his fists, and began the chant.

"Silver and iron to the origin. Gem and the archduke of contracts to the cornerstone. The ancestor is my great master Schweinorg.

The alighted wind becomes a wall. The gates in the four directions close, coming from the crown, the three-forked road that leads to the kingdom circulate.

Shut (fill). Shut (fill). Shut (fill). Shut (fill). Shut (fill).

Repeat every five times.

Simply, shatter once filled.

――――I announce.

Your self is under me, my fate(doom) is in your sword.

In accordance with the resort of the Holy Grail, if you abide by this feeling, this reason, then answer.

Here is my oath. I am the one who becomes all the good of the world of the dead, I am the one who lays out all the evil of the world of the dead.

You, seven heavens clad in three words of power, arrive from the ring of deterrence, O keeper of the balance ―――!

Yet, thou serves with thine eyes clouded in chaos.

Thou, bound in the cage of madness. I am he who command those chains."

There was a flash of light, and then... nothing. The circle was empty.

Zouken smiled darkly as he spoke, "Is that it? Unbelievable, you couldn't even summon your own Servant! It looks like Sakura will have to-"

Suddenly, a blast of blue light erupted from the circle, incinerating the rusted piece of armor. Zouken reflexively brought his hands up to defend himself while Kariya stared into the light with surprise. In what felt like a few minutes, which were in reality as many seconds, the light faded, leaving the Servant to be seen.

Zouken looked the Servant and simply stated with a small grin, "Well, it appears you're not completely a failure after all, Kariya. You summoned a Servant, even if it wasn't the one I was... expecting."

Kariya gave the human worm a glare that would have incinerated him and turned to look at his Servant, the worms inside of him crawling about in response to his confusion. He had been expecting some sort of armored knight, which was not what he was looking at.

The Servant in question was a girl, which was definitely not what he had expected. She appeared to be about fourteen or fifteen, with a petite build of a girl who had not quite hit her... growth spurt yet. She had ash blonde hair fashioned into two pigtails and large green eyes that seemed to look straight into his soul. She wore a typical schoolgirl outfit and a trench coat with a cloak-like end, a white blouse with a yellow sweater vest, a red plaid skirt, and black boots with white buckles, with her hands were covered in white gloves. All in all, if it wasn't for the weapon in her hand, she would have easily had blended in among a crowd.

The weapon in question was, to Kariya's surprise, a scythe. It had a long grey, staff-like haft with the sharply curved blade being two colors, the top half red and the bottom black, separated by a line that zig-zagged three times from the base of the blade before becoming straight the rest of the way. What caught the eye however, was the decor attached where the blade met the haft. It was in the shape of an elliptical red eye with a black pupil, framed by golden metal which went around the eye and split into two strands of metal that latched onto the end of the blade. Two small wing-like objects, one black and one red, were attached to the eye, opposite of the blade.

As Kariya took all this in, the Servant finally spoke in a kind voice, "I am the Servant, Berserker. I ask of you, are you my Master?"

Kariya was surprised. If this was truly Berserker, then why was she able to speak? Still, he found it in him to answer. "Yes." He suddenly broke down into a coughing fit. Damn his failing health.

Suddenly, Berserker was by his side, patting him on the back. "Are you alright?" She had a worried expression on her face. What was wrong with him?

Zouken finally spoke, "Well Kariya, it appears you have indeed summoned a Berserker. An interesting case, at that. Just remember, give me the Grail, and Sakura is yours. Though I wouldn't put too much stock in someone like you."

Berserker suddenly rushed forward, swinging her scythe back and slicing Zouken in half. Zouken's body crumbled into its individual worms and moved away, quickly reforming after he was out of range. He now had a scowl on his face.

"Well, perhaps I spoke too soon."

Berserker prepared to rush forward again, but Kariya cried out, "Stop!" She turned to look at him.

"Let's go. Staying here any longer would be useless." As much as he wanted to see Zouken dead, he knew that he still needed to be alive. He started walking up the stairs, then stumbled on the sixth step and began to fall forward. He braced himself for impact, but after five seconds, he looked and realized Berserker had grabbed him.

"Are you sure you're all right, Master?" She was actually concerned for him. It really touched him.

Kariya began walking again, this time with Berserker as leverage. "I'm fine. Let's just get out of here."

Maybe, just maybe, he could win this Holy Grail War.

Zouken, on the other hand, simply had one thought going through his mind.

"What the HELL is going on?"

X the Reaper proudly presents:

Fate: Zero Sanity

And so the prologue to what will hopefully be remembered as a epic begins!

I'm going to guess some people are going to know who at least some of the people introduced here are. However, Saber, Archer, and Rider are all the same.

Once again, give thanks to The Infamous Man, the one who inspired me with this idea, and Sentinel07, the one who inspired me to write in the first place!

Starting next chapter, hopefully, I'll be able to get the Servant Skill Sheets up, which will go into their abilities and maybe answer some of the questions that are no doubt on the viewers minds.

And yes, Caster and Avenger will be summoned in the next chapter.

So people, what did you think? Did you like it, hate it, think it was the greatest thing since sliced white bread, or think it was complete sh*t? Leave reviews. They feed my creativity.