Prologue: Shinji Matou, Spellcaster

Summary: Due to a chance meeting with Kariya before the events of Fate/Zero, Shinji strives to follow in his uncle's footsteps and save Sakura from damnation of the Matou Clan. To do so, he must make many sacrifices and will endure pain like no other to compete in the next Holy Grail War, including becoming a Spellcaster—all for Sakura's sake.

Before the 4th Holy Grail War

Shinji Matou should have been in bed that night, slumbering before his flight out of the country to study abroad. But he couldn't sleep. It was a small thing—just a bit of anticipation and fright before he went far away and would leave his home, his grandfather, his father, and his new sister, Sakura.

He was her big brother now and soon to be the head of the Matou house. The head had to look after the youngest, so he opened his arms and accepted her, a stranger, into their home. He took that quiet girl and showed her around the house, teaching her how things worked since she was new here.

Despite what he said, Shinji had kinda gotten to like Sakura over the last year or so. He simply showed it in a different way. Sure he picked on her occasionally, but that was because it showed her he noticed her.

Not like his grandfather, who ignored him for the most part. Or his dad, more so lately since he had started drinking even more than usual. He didn't know what happened to his mother, only the fact that she died.

Seeking to remedy the lack of sleep, he decided to get a glass of milk from the kitchen and made his way down the Matou estate to do so, passing by the floor where the family head's study would be. He wasn't allowed in it yet, nor the basement, but once he became the head when he was older he could go wherever he wanted. Entering the kitchen, he froze as he saw someone there. Who was this pale, ugly man who trespassed in their home?

"Ah…" said the man in a raspy voice, after a long and arduous breath. "Shinji? I see you've…gotten bigger than the pictures I'd seen…"

That voice sounded familiar to Shinji, on he heard over the phone arguing with his father. Taking a guess, he said, "Uncle Kariya?"

The man nodded weakly, making his way over to a chair. "Yeah, it's me."

"What happened to you?" Shinji asked. He only saw his uncle in photos, but he didn't look like this.

"Oh…" he froze, trying to think of what to say. Shinji didn't know about the Matou magus line just yet, if they ever planned on telling him. The kid didn't realize how lucky he had it. "This…was the price I paid for power. Is Sakura around?"

"She's asleep," Shinji said.

"I see…" Kariya let out a pained sigh and sat down the chair, his head leaned back with the hood of his parka covering his eyes. "Ah…I could use something to drink…"

"Let me get it," Shinji said, going to the refrigerator and opening it. Looking at the contents, he pulled out a bottle of water and placed in front of his uncle.

"Thank you," he said, before quietly drinking it down.

Shinji watched him while pulling at the bangs of his hair. He wanted to try and gather up the courage to ask what he always wanted to know. His father and grandfather (whenever he saw the old man) seemed to dislike him. "Why did you leave the family? Dad always complains that you should be the one to be the heir…"

It boggled young Shinji's mind that someone would turn down the wealth of the Matou home, being one of the oldest families with ties everywhere in Fuyuki. They had hundreds years of history in this land. What about their family name was so bad that the one who should have been the next family had ran away and forsaken it?

"Byakuya said that, huh?" Kariya let out what sounded like a mad laugh before sighing again. "I imagine living as your grandfather's puppet has left him a shell of a man. He should have followed in my footsteps and left this place behind, even if it meant becoming a pauper. Maybe then he could've lived a life with you and your mother away from all this and let the Matou name fall into oblivion like it should."

Shinji blinked. "But…why did you leave?"

"Pray you never find out," Kariya told him. After a moment of looking at his nephew and seeing a younger, innocent version of his brother, he said, "The Matou Clan has many dark, disgusting secrets, Shinji. To be the head means to learn them all and endure the suffering that comes with it. Your father's drinking came from those secrets, and my body is breaking because of them as well. I came back so Sakura could be freed from those secrets and suffering."

"What do you mean?" Shinji asked as he sat in a chair across from the man. His little sister was suffering? He just thought she was quiet. As the one looking out for her, he should know these things.

"Tell me Shinji," he said with a rasp. "What do you see when you look at her?"

Sakura was weird since he had known her. "She's quiet and…empty. It's creepy."

"She wasn't always like that," Kariya said, his lips trembling. "She was outgoing, like her mother, Aoi Tohsaka, only for that to be snuffed out in three days time."

So her original last name was Tohsaka…Shinji thought. He never did learn who Sakura was before she got here. He never thought much about it. "You knew her mother?"

"I…was in love with her mother," he said. "I wanted her to be happy, so I left her with someone I thought she could be happy with. I wanted her to be happy no matter what and so I bowed out and left to get away from the old vampire's plans and risk sentencing her to the same fate as your mother."

Shinji noted the man's features growing darker with rage, his hand crushing the bottle so that the remaining water surged out and washed over his quaking hand. "Then I learned that Sakura's bastard of a father abandoned her to Zouken!"

Kariya started coughing violently and Shinji was afraid for the man's health...and kinda scared, but he wouldn't admit that. "U-uncle?"

Kariya took several deep breaths and calmed his soul. "Shinji…I'm going off to fight for her. If I don't make it back…"

Shinji swallowed in anticipation at the words that he seemed to be struggling to say. "Yes?"

"Please, look after Sakura," he asked in voice that was trembling with resolve, but he held no delusions about his chances of survival. "Cast out of her home, forced apart from her mother and sister by the bastard, and now…she has to bear that unholy thing our family calls a legacy. Please…"

"I will," Shinji said after a moment. "I promise, no matter what. It's my job as the older brother to do that, and the future head of Matou."

"Thank you," the older Matou's expression softened after that and Kariya rose from the chair and made his way to the door. For the first and last time, Shinji saw his uncle smile as he opened the door and walked away in his half-broken body. He wouldn't see his uncle ever again after that, but his promise would remain in place for years to come.

It was some time later when Shinji learned just what horrible secrets his family held onto. While he was studying abroad, he received one final thing left behind by his uncle. It was a letter, telling him that he wished for Shinji to remember their promise: Look after Sakura.

In order for him to do that, he needed to know the sins of the Matou, so he could understand her pain and sorrow. So, keeping his promise, Shinji disobeyed his father and looked into the room where they often took Sakura for hours on end…only to see the nightmare that was every waking moment of Sakura's life.

The sound of the meaty worms writhing around, hungrily partaking in the girl's innocence as she lied their lifeless, was sickening. Even more so was the smell of the dark and dank chamber. There was no hope to be found inside that…that…hellhole.

Shinji shut the door and ran, unsure what to do or think. Why did his father and grandfather subject her to such a thing nearly every day? Why didn't she say something?

He needed to know why, but his father was dead drunk somewhere and his grandfather…Shinji shivered at the thought, somehow recalling that same feeling he got from that place and his elderly caretaker. He needed answers, and there was only one other place to get it since his uncle had died.

He entered the study that only the head of the Matou could enter and combed through the knowledge there for hours without realizing it, learning that his clan was one of Magecraft users. Those worms were a part of their family's mysteries, and that was considered training for the head of the clan, meaning she was the head and not him.

For a moment, he was angry. That moment passed when his thoughts came back to that pit of worms and basement of corpses. Sakura didn't deserve hatred, not for saving him from that. Now he had to return the favor.

As he looked over more and more of the information, more pieces of the puzzle fell into place. His uncle had the right idea about getting away from his family and saving her. The question was how was he going to save Sakura?

He lacked the Magic Circuit to perform Magecraft according to the notes he found. His uncle had them and failed apparently due to a lack of formal training. So how was he going to do what Kariya failed to?

"There has to be some way," Shinji muttered as he fished through the numerous tomes for even one that would give him the strength to do so. It was then that he brushed off an old tome on the back shelf, hand-written and authored by his grandfather.

And Shinji saw it as the answer he had been searching for.

It would take time, but even if it was one-chance in a fifty, he would become capable of Magecraft, free Sakura, and, better yet, change the system of the Matou into something that didn't make his skin crawl. His uncle ran away from the Matou name out of disgust. His father resigned himself to being a puppet of the Matou name, drinking away his sorrow. His grandfather clung to their aged traditions, continuously in pursuit of a goal that sacrificed even family to do so and the price of failure was steep.

Shinji would surpass them all.

Three Years later

Shinji went silent for final time, his mind teetering on the edge of destruction once again after he screamed loud and hard for roughly half-a-day before the spiritual surgery was complete. Lying naked on a platform in the basement that normally served as Sakura's training grounds, Shinji Matou had been reborn through the hellish pain of having his very soul perverted to an extent that even the girl could sympathize with. His body had become paler than before, as the physical expression of the what now resided in his soul stretched through his body like a second nervous system, and the strain of the surgery had gave him bleach-white stripes alongside his blue hair.

"I had to admit, I was rather surprised by your request," said a man dressed in an ashen robe that had seen many years, with a cowl shielding his face. In a soft, but crude voice, he continued with, "To transplant the circuits from a magus to a non-magus was something that few would ever do on sheer principle—after all, circuits run the risk of being destroyed like that for nothing."

A wet chuckle came from Zouken's mouth as he looked from the boy to the Spiritual Doctor he enlisted from an old contact he still had in Russia. "I figured I may as well take the defective materials I had to work with and see if something productive could be made from them."

To be honest, he found it amusing and somewhat unexpected that his useless grandson managed to endure each session. It was even more amusing that the boy was the one who opted to take his dying father's Magic Circuit after reading up on an old theory of his. To think he had originally considered just getting rid of the boy after Kariya somehow managed to convince him to accept—not just tolerate, but actually accept—the girl.

Upon having the role as the head of the Matou taken from him to be given to her, something he was supposed to think was his birthright, Shinji was supposed to have become abusive, driving her further into despair over time. Once puberty kicked in and the worms inside her became active a few years before the next war, he would also serve a purpose of keeping her in balance by dealing with those urges. Zouken did not like changing his plans, even though he was perfectly capable of it!

But such a death, while it would still serve to drive a minor wedge into the girl's mental defense, was pointless for the moment. Fifteen circuits of the twenty-three from Byakuya's soul managed to successfully integrate into him. It was less than the average magus, admittedly, but still a boon given the low-rate of success.

Magic Circuit Transference—it was an absurd idea Zouken had conceived in his youth, shortly before discarding the notion and relying to his current method of prolonging his life through his worms. The process of engraving the circuits onto Shinji's soul was excruciating, to say the least—what with peeling away his humanity inch-by-inch, exposing his naked soul to the absent mercy of the doctor, who soldered one circuit as slowly as possible to get the best results every session. The boy had far more willpower than even he expected just to function after the first surgery, let alone the twenty-third one.

Even though Shinji lived through the process and somehow came out sane, if results were consistent with the last twenty-two times, his body had been weakened and he would suffered as his uncle did. It would be a constant reminder of what awaited those who disappointed him and a living monument to the price others paid for the girl's sake, never allowing her to forget that it is all because she refused to simply give in.

Zouken looked at the boy again, pleased to a small extent that his earlier research held up to his standards. "Are you not satisfied for being called out for such a monumental task?"

A smile crept up on the doctor's face. "The simple fact that I may have successfully created the first artificial magus alone, with these hands, was more than enough of a reason for me to come. The research on his body's rejection of the foreign elements of the first five circuits and then acceptance of seventeen due to a hereditary Sorcery Trait thought useless was more than enough. I dare I may take my fruits to the Department of Spiritual Invocation in the Clock Tower."

Zouken had to admit that for the process to go so well, even with the somewhat talented Spiritual Doctor transplanting the circuits, was simply an unexpected boon from the Sorcery Trait he inherited from his mother. She had been the daughter of a third-rate magus from the continent that Byakuya had wedded and was a Carrier for the Sorcery trait 'Inheritor', which should have maximized the chances of Shinji having circuits upon birth. However, even if that didn't happen, the Sorcery Trait was still inherited and made the transference of the circuits much more plausible.

Inheritance covered many things. One could inherit wealth and other things upon birth…or the death of the original owner. Why should the Magic Circuit be any different? Maybe he had been too hasty in discarding the woman rather than forcing her to deliver another offspring through some lesser means.

Byakuya had been a failure, of that he had no doubt. The fact that Shinji had managed to enter the study for the last few years as he pleased due to his father's lush behavior was even more of a reason for Zouken to dismiss him. But, in light of the success, Zouken decided that Byakuya would finally be allowed to die in peace, compared to his current state of being placed between life and death for the transplant.

The writhing of the gross familiars everywhere bought another thing to the mind of the doctor. "While it was a success, I am afraid that the use of your clan's mysteries through typical means would result in his complete destruction. I would prefer he lived long enough to show he is capable of the Art to even a small extent to further my research. He shouldn't attempt anything for at least a month, and I would like periodic reports of his progress over time."

"Very well," he agreed to all the requests, especially not to use the Crest Worms as he did Kariya. It was not out of kindness, but the fact that the grail wouldn't be active for some time and, as it stood, Shinji would be lucky to reach his father's age. That being said, he wouldn't waste any more time than he already did outside of training the girl and plotting his next movements.

Shinji would simply have to make do with what he could find until the war began and he ran out of uses. Perhaps, out of some sense of twisted and sadistic post-mortem gratitude for the woman who had been the boy's mother, he would reach out to her remaining family and have them take the child for a year or so and rehabilitate him.

It never hurt to be thankful.

One Month Later

"I'll be leaving for a little while, Sakura," Shinji said as he patted Sakura on the head. "It's only for a year or so, but I'll come back for you better than ever before. In order to keep my promise, I'll become a magus."

Sakura looked at her older brother with tears in her eyes. So far he had been the only light in the darkness after uncle Kariya died, showing her the price of fighting back against their grandfather. Even then, she could see Shinji was suffering just to do this for her. "Nii-sama, your health—"

"I'll be fine," he switched to giving her a light noogie. "From what I've learned, Mother's sister is taking me in and passing down what her father practiced. Since he was just a third-rate magus by standards, that isn't much and it shouldn't put too much of a strain on my body before I get accustomed to using my circuits. Plus she's some kind of medicine woman too."

He leaned in and whispered into her ear. "Hold onto hope, and wait for me. Okay?"

She nodded, watching as he got into the car and prepared for another long trip. She wiped away the forming tears and refused to cry anymore as Zouken approached her from the side and prepared to usher her into the hellhole again. She would bear it without her brother's kindness, clinging to that distant hope.

One Plane Trip Later

Fang Yin was not happy to be in the airport, waiting her sister's son. Not after her sister died because he supposedly wasn't born as with a Magic Circuit. Now he had been supposedly turned into an Artificial Magus?

Bullshit. If such a thing were possible in the first place, why did her sister have to die as the price of failure before that old worm…If he hadn't paid upfront enough money to let her thrive for the next few years she would have hung up the phone and burned it for good measure, so she didn't have to even think of hearing his slimy voice again. She hated the Matou name as much as she hated her father.

Her father was just a third-rate magus who got himself killed pursing the Art. He had been lucky enough to have been born into a family with relatively new linage and a Sorcery Trait, but unlucky enough to be born without talent and thusly passed up for his family crest that was starting to develop. He wasn't supposed to learn of magic, but he did and decided to attempt to make it on his own, taking what little knowledge he could gather in time and running off only to die a pauper who sold her beloved sister for a chance to explore and recreate a dying craft.

Her sister resigned to her fate without complaint, seeing it as a chance to better their lives through sacrificing hers. The money paid by Zouken would help their father accomplish his goal somewhat and they would have enough to live. Fang Yin trained in her abilities in Chinese Alchemy rather than her father's field, allowing her to produce medicines and concoctions that still held a great deal of worth to the populace of her country, even in this age of digital encroachment.

But more money never hurt, and she would admit she was greedy after growing up poor. So she'd take the brat in and teach him the minimal basics to become a third-rate magus seeking knowledge for knowledge, hand over the remnants of her father's research, and then send him back to the worm thing in the shape of a bitter, short, impotent old man.

As she spotted the pale boy with blue and white hair, she resigned herself to her task. To think her sister died to give birth to a carbon copy of that puppet man…with the exception of his hair. She spun on her heel and started walking after he met up with her. "Keep up boy. I won't slow down for your sake since I have a tall order to fill this week."

Three Days Later

"I've told you," Fang Yin said, tired annoyance lacing her voice. She had already given him medicine laced with magical energy to force open the Magic Circuit and now she was telling him to switch to the circuits as the feeling in his limbs returned. "You need to have something that triggers a reaction to serve as a switch on your Magic Circuit."

Shinji huffed in frustration and gritted his teeth as the sweat rolled from his brow. Everything was harder than he had imagined for the last three years upon reading the knowledge from the Matou study. Practical application was always harder in retrospect, let alone with the added difficulties.

He was burning as he tried to trigger the fifteen in his head to open. The scent of weird medicines in the small studio apartment that served as the location of where she practiced the Art seemed to make him feel even dizzier than before, entering his nose and perverting his mind. He could feel the sheer animosity rolling off the woman as well.

Shinji wasn't dumb. He lived with Zouken and his father, who were far less reserved about it than her. The source of their anger was always his Magic Circuit. The men disliked him because he lacked them, and now that he had them she disliked him. As long as it didn't hinder his training it was fine.

After another failure late in the evening, Fang Yin merely told him to go to bed. Lighting the elegant tobacco pipe she pulled from her robe, she wandered off to get back to her own craft and pushed the thoughts of the Byakuya clone to side and delved into her work. Hours later, as the sun was beginning to peak over the horizon, she surfaced from her workshop and back into the room…only to see the brat still going at it.

What the Hell? Fang Yin thought, listening to the Byakuya clone swear under his breath words that a boy his age shouldn't know. He was still trying? "I thought I told you to go to bed, Brat."

He shook his head and tried once again to access his circuits.

"You're just burning yourself out," she said, slightly more annoyed that he didn't listen. "It can wait, you have all year."

"Don't say something as ridiculous as that," he said in an aggravated and tired tone, trying to conjure up a mental image strong enough to invoke a reaction to fire off his inherited circuits. "I can't afford to take this slow and lounge around. Not on this."

The stupid brat is going to kill himself from exhaustion at this rate, she thought, watching him try again. A mental debate waged to see if she should just knock him out and drag him to bed, but she relented, allowing him to do as he pleased. "Fine, just try to die without making a mess."

Later…

Oh, come on, Fang Yin thought. Shinji's figure was paler than before and his shirt was stained and soaked through. He was still trying! Honestly, he really is going to die at this rate.

On one hand, she could go back to not having to feed more than one person a day. On the other, the old worm would be crossed…no, he wouldn't care that an unimportant puppet like him had gotten broken. That old worm kept the things he truly valued closer to his chest and within reach.

Screw it, I don't feel like getting rid of a corpse today. Fang Yin sat down, crossed her legs, and flicked him in the head, causing Shinji to yelp. It hurt a lot more than he expected. "What's the rush? Are you that eager to die or follow the words of that old worm?"

Shinji looked up at her. "I am not like my father and I'm not doing this to please grandfather."

Fang Yin raised an eyebrow.

"Even if I possess father's circuits, he was a failure who bowed to grandfather's wishes and drowned himself in sorrow as a puppet," he said, concentrating again. "I have no intention of doing the same. I promised uncle to protect my sister and for that I need power for that alone."

That was news to her. "What sister? You were an only child."

"She was adopted from another magus family that followed the tradition of one magus per family and given to grandfather to be…trained." Shinji shuddered, briefly recalling the scene of those things all around her. "She doesn't complain about or anything, she just accepts it without fighting back, so I have to do it for her."

Fang Yin felt a pang of rage and sympathy. That was the same thing that happened to her own sister, bought by that old worm to serve a purpose.

"I know that there's nothing I can do now," Shinji continued. "As a mere human being, I could do nothing to help her. Being a patchwork magus, my uncle failed and died defying the old man, only driving her further into being a shell, while my father simply drunk himself stupid. That's why I will accomplish my uncle's goal by keeping my promise—no, better yet, I will be a superior magus than them both and use that power to save Sakura."

"You've got brass ones, Brat," she said after a moment. "But you're wrong. A magus is someone who studies the Art for the sake of reaching the Root and simply knowing. You're talking about using the Art as a tool, a means to an end."

"I don't care about knowledge for the sake of knowledge," he stated. "If it can be used to help Sakura, I'll use it. Magical or otherwise, I want to break her free of the Matou name before I redeem it through purging the rotten worms."

Fang Yin reconsidered her plans for him. Originally, she was just going to drag him along through slow self-study to make him barely a third-rate magus. But if she was turning him into a Spellcaster instead…she could work with that. "You know the old worm will never let her go, right?"

Shinji's eyes became narrow. "I'll find a way to deal with him eventually. Unlike my father and uncle, I won't run from the Matou name. I will reform it and get rid of the current system…after all, why should I accept a system as vile as that when I run it?"

Brass ones, she thought to herself. If he actually managed to kill the old worm somehow, it would be revenge for her sister. Even if he didn't have the ability to, as long as he was trained enough to be competent then he would be able to survive long enough so that the girl wouldn't be all alone.

"Explain the process you're using," she demanded impassively. She had appearances to maintain after all. "Be quick about it, I'm a busy woman."

Wiping sweat from his eyes, he gave her the step-by-step process he used.

"You're not using a strong enough mental trigger," she settled on. "Every magus responds differently, but it seems like you aren't producing an image strong enough to flip the switch. It may be because of the transplanted circuits, or the fact that you weren't a magus to begin with."

"Then what am I supposed to do!" Shinji demanded, getting another flick. In his defense, he was still tired, sweaty, hot, thirsty, and in pain.

"Use your worst fear to drive yourself forward," she said. "Until you can think become accustomed to using a different mental trigger, use what you fear the most activate your circuits for now. The sheer terror alone should have enough of an impact to do so."

His mind was a void as he tried to reach into the recesses of his imagination to find the necessary vision to trigger the reaction he needed…

And was rewarded to the sight of Sakura lying in that bed of worms and decay once again, a sight he never wanted to see again. But it got worse, as Sakura reached towards him and started screaming—something he never heard considering she had been hollowed out well before they had met due to his grandfather introducing her into that nightmare after not even three days of being in that household.

As she reached for him, her flesh was devoured by the worms. Sinew, tendon, eyes, organs, hair—they consumed everything with sickening squelches and loud chewing. The meaty, grubby worms left only bleached white bones that still seemed to reach for him in agony until they too were devoured.

"Guh!" The formless switch was flipped and the sensation of being melted rolled across his body, as if being turned into water in the transition from a solid to a liquid. The liquid body was filled with the mana that lingered in the room, absorbed and transmuted to magical energy to be processed. The molten substance ate away at his nerves as they inverted into circuits and the illusion of steam wafting off his skin as the liquefied contents of his insides were starting to boil.

The price of success was steep and Shinji lost himself in that pain as prana surged, running their course and flooding the circuits for the first time of his own violation. He passed out, his body convulsing briefly and then settling.

Fang Yin bit down a swearword in her native tongue as she inspected him. He had passed out, but it was just from the shock of going full throttle at the start of his training and dehydration. Reaching for a bottle of elixir, she prepared to give him a swig to deal with both at once. He couldn't die now, not before she tested his resolve.

Two Weeks Later

Progress was being made now that he could toggle the switch on his Magic Circuit. The consecration Fang Yin conducted showed his element was water, as expected of the Matou clan. His Origin was what the main problem was and the reason for that personality that screamed he wanted to be on top and was entitled to great things. His Origin was 'Predominance.'

Predominance—the desire to be superior—was troublesome. He wanted to be superior to his father (a mere puppet), his uncle (who was a ramshackle magus who fought and failed), and everyone else in general. At least it was somewhat driven in a good direction by trying to be a better brother, who would look out for his lesser sibling.

She opted out of telling him that though. The Origin was a cause, but if he knew of it then it would become impossible to separate him from it. As it stood now, he had a chance for improvement before things went south once he started getting older and feeling entitled to doing whatever the hell he wanted to women once those hormones kicked in.

"Why am I stuck writing symbols on these slips of paper, over and over!?" Shinji exclaimed to the woman smoking from that elegant pipe she carried, breaking her from her thoughts. "I thought you were going to teach me to be a Spellcaster and use my knowledge practically. How is scribbling characters on a slip of paper practical?"

Fang Yin's only response was to take his brush, dip it in the ink well, grab a slip, inscribe a character while channeling prana and then sticking it on his head. Shinji's gave a muffled cry as his body felt far heavier and it felt like gravity was stomping him into the ground. She blew out a puff of smoke in his face as she kneeled down and looked him in the eyes as he coughed.

"You need to use something established to practice besides the basics of Material Transmutation to gain and use magical energy, if you want to be a halfway decent Spellcaster by the end of the year we have. For all the studying that you claimed to do in Japan, little of it was Formalcraft, which knowledge of is necessary and I don't have, so we're using what my father researched—his half-completed knowledge of unique Shenfu (Talisman) and Fuwen (Magic Writing).

"You have no lineage because you don't carry your family's crest, just as my father had no Magic Crest since he wasn't the one to continue as his family heir; after all it's like transferring a major organ and can't be split. He wasn't supposed to have learned about magic at all and live a normal life, but he did learn about it and split himself off from the main family to attempt to succeed as a magus. He failed, but his knowledge can be used to aid you.

"That ink you're using contains your blood, laced with magical energy since it clings to fluids better than nearly anything else outside the body. The fuwen he collected cost a great deal of money since they came from several Fulu Pai and managed to get compiled into something useful, but the principles are the same as runes. Combined with shenfu, they can store magical energy in them temporarily or realize a mystery at your discretion."

There was a snap as the shenfu placed on him deactivated, allowing him to move freely once again. He just didn't because the woman scared him a bit. He might have been better off when she didn't take an interest in him.

"Every day, you will realize a mystery through fuwen and every time you fail at you will do it over, along with the basics of reinforcement and transformation. Then I'm putting you to work," she finished her lecture and watched as Shinji cringed.

"Work!?" he sputtered out.

"Of course," she said as she stood, looking down at him. "I'm taking my time out to train you, so I'm putting you to work as my assistant while you're here. If you're lucky you can pick up a few tidbits of knowledge in the process, so you can deal with that weak body of yours that breaks down under the weight of your own mysteries."

And so he learned over the course of the year.

With the circuits he inherited and the knowledge he gained from Fang Yin, combined with his own creativity and drive, Shinji Matou would become a major player in the grail war in his attempts to succeed where his uncle had failed.

Authors Note: Now, I had this idea on revamping Shinji after I realized that even though in canon he was a horrible person, he was nicer as a child and the situation of his household may have been one of those factors that changed everything. His mother, who had a Sorcery Trait left untapped and was the daughter of another magus, was killed by Zouken, his father became a distant douche upon him learning about Sakura, and his grandfather…well, he's Zouken. Do I even have to say it?

So, what if Shinji met Sakura shortly after she arrived, as well as Kariya and Shinji mother's side of the family had met with him and it led to him being a better person to Sakura? Not a hero, like Shirou, or a complete monster of a magus, like his grandfather. A Spellcaster and jerk with a heart of gold.

This is a combination of Characters and Plots form Fate/Extra, Fate/Prototype, Fate/Stay Night (Anime, Manga, and Game), Unlimited Blade Works, and Heaven's Feel. Even though I'm a fan of the Nasuverse, I'm not as adept at several factors and legends I have planned so research will slow me down in making what will hopefully be a decent fanfic.

I will probably be screwing around with some facts and borrowing some elements from other fanfics, but if you think you can do better, I encourage it as a challenge and see my profile. This is an untapped field after all.