Matou Shinji and the Heirs of Slytherin

A Harry Potter / Fate Stay Night Story

Disclaimer: Though I wish it were otherwise, I do not own or in any way, shape or form hold a legal or moral claim to elements of either the Nasuverse, the Potterverse, or other works I may reference in the course of this story.

Summary: Trouble is brewing in the Wizarding World. In the wake of the Stone Incident, Albus Dumbledore has begun quietly preparing Britain to survive the coming war. The Stone Cutters, a new organization at Hogwarts for the most talented and distinguished of students, seek new blood to bolster its strength. The Boy-Who-Lived seeks his destiny as the Heir of Slytherin. And a boy from the east meets a specter of the past.

Chapter 20. The Shadow of Truth

"…did you say Einzbern?"

Shinji swallowed, his face paling as he sat in a conference room at Mahoutokoro, with Aozaki Touko herself briefing him about the situation in Fuyuki. He'd thought that he would have been prepared for anything when his Master had told him they needed to talk, but he hadn't expected to learn some unsettling facts about his home town – and the people in it.

"Yes. In fact, beyond a simple association, Emiya Kiritsugu, the freelancer known as the Magus Killer, married into the Einzbern family," Aozaki Touko confirmed, her lips curving up into a cruel smile as she took a long drag on her cigarette. "Are you aware of what that implies, Matou Shinji?"

And he was.

As a Matou, if not the heir of the old family, the basics about the Three Founding Families of the Fuyuki Grail War and the relationship between them had been drilled into his head. Tohsaka, Matou, Einzbern – the three which had cooperated to create an omnipotent vessel and a gateway to Akasha, beyond the reach of the both the Mage's Association and the Holy Church.

At the time, the two had been engaged in a centuries-long war to the knife, which was one of the reasons for the philosophy that to be a magus was to walk with death, because beyond the simple risks of using one's circuits and devising new spells – those which were emphasized today – becoming a magus had meant accepting the enmity of the Church, and conflicts with its agents.

Even now, after the conflict had officially ground to a halt at the insistence of the Alchemists of Atlas (which effectively was an independent entity with its own foreign policy – and could maintain this position courtesy of a store of superweapons capable of ending the world seven times over), with Church and Association signing a non-aggression treaty, some level of wariness lingered, neither quite trusting the other not to engage in off-the-record conflict, sabotage, or other mischief.

Which indeed, both were guilty of, given that official or not, the ancestral enemy was still regarded with suspicion, as one never knew what treachery the other was capable of, and so both used the time of peace to build up their military strength in case the next war came.

But in the Far East, magi had not had to worry about such things, given that neither organization really had a strong foothold even to this day, and users of magecraft and other powers had been accepted readily enough until the Opening of Japan. Thus, it was there that the Tohsaka, Makiri, and Einzbern had worked together without fear of discovery, with the Tohsaka providing the second greatest spiritual land of Japan, the Makiri stabilizing the materials and designing the Command Seals that allowed mere mortals to command Heroic Spirits, and the Einzbern creating the vessel for the Grail and the vast apparatus that allowed the ritual to take place.

So if a man – a deadly killer – associated with the Einzbern, had resided in Fuyuki for a number of years, there was only one conclusion to be drawn.

"Emiya Kiritsugu participated in the last Grail War," Shinji said, a shiver running down his spine as he spoke the words and wondered what it would have been like to face the man on such a battlefield. "As the representative of the Einzbern."

"Yes."

"Then is Shirou…" …an Einzbern himself?

At this, Aozaki Touko leaned back against the wall, eying her apprentice critically.

"There isn't much we know of Emiya Shirou," Touko noted, arching one slim eyebrow. "The boy appears in the historical record only after the Fuyuki fire, when he is adopted by the Magus Killer. There is no indication of who he might have been prior to that."

"…ah."

He hadn't known that. He'd always assumed Shirou was simply his father's son, but then, he'd been away at boarding school during the Fourth War, and hadn't been witness to any of the destruction it had produced.

Still, he knew Emiya Kiritsugu had survived the war, unlike Uncle Kariya and Tohsaka's father.

…did that mean that Emiya Kiritsugu had won? But if so, why had he not returned to the Einzbern family covered in glory, with the world changed from the power of a wish? Why had he remained in Fuyuki, presumably without the permission of the Second Owner (not that that would have been difficult, as it was quite possible Rin simply didn't know that Emiya Kiritsugu was a magus in the first place, since the girl was almost entirely self-taught)?

Why had he adopted a son?

It didn't make sense. Well, unless the Magus Killer had actually been defeated, or the war had once again been inconclusive, and the Einzbern had instructed him to raise a local boy as their agent on the scene.

…though did that mean Shirou was a magus? He had to assume there was some reason Kiritsugu had adopted the boy…and whether he was or not, he had to assume that whatever else, Emiya Shirou knew of the role of the Matou and Tohsaka families in Fuyuki.

"Are you suggesting I don't go to the funeral, Master?" Shinji asked quietly. It probably would be simpler if he simply didn't go, given that attending risked getting into business traditionally handled by the Second Owner. On the other hand, the fact that he'd been invited was probably significant…

"That is your choice, Matou," Touko replied, shrugging her shoulders slightly. "As it so happens, I do not need you in Mahoutokoro over the holidays."

"Oh?"

"I have a commission to design an apartment complex as an embodiment of Yin and Yang," she explained, taking another long puff of her cigarette. "The client is in Mifune City, so I must head there. You are welcome to come along if you desire, but the choice is yours."

"Ah." An errant thought struck his mind while he sat there, thinking about what unpleasantness might result from the situation if things became complicated. "Did you receive my note about Tom Riddle, Master? And uh…how a diary I encountered had a piece of the Dark Lord's soul inside it?"

Touko smirked, having been expecting a question along those lines.

"If you're asking about Tomas, then no, he is not the one known as Voldemort, even if he once shared the same name and origins," the redhead noted coolly. "His path diverged from that of his originator when that portion of his soul was separated from his body, frozen in time."

"...he prefers to be thought of as a Peverell," Shinji surmised, remembering a conversation he'd had with powerful – and talented – puppet. "One of those which created the three great artifacts of Magical Britain – the Wand, the Stone, and the Cloak."

"In life, Tom Riddle was much like you, really," the Aozaki puppetmaster commented. "A boy dismissed by his parents as worthless, whose only refuge was in power and manipulation. A boy given the chance to be special – told he, too, had the gift of witchcraft. A boy who discovered many secrets, dabbled in the forbidden arts, took whatever means were necessary to become the strongest – someone no one could throw away."

"But…" Shinji started to speak, but fell silent. For he remembered Quirrell's – Voldemort's – philosophy that there was no such thing as good or evil, simply power and those too weak to seek it. And from a certain point of view, if one became the most powerful, one could simply define what was right or wrong, while others would have no choice but to accept that paradigm. So instead, he simply asked: "Do you trust him, Master?"

Aozaki Touko smiled at her apprentice's query, but there was nothing friendly or pleasant in her expression.

"Trust isn't an issue when I hold his existence in my hands, Matou," she answered, with Shinji freezing as he remembered that this woman – this person who joked with him and deigned to teach him – was one of greatest magi of the age, and as such, was a monster beyond anything else he could imagine. "He exists as one of my puppets. As such, I can snuff out his life with a thought, if I so desired."

She held his gaze for a moment, with the boy knowing in the marrow of his bones that she meant every word of what she said – and that she would have no problems with ending a life, if necessary.

It was strange, really, how magi, though biologically human, diverged so far from the mentality of those around them, becoming more like monsters than monsters themselves. Practitioners of Witchcraft – at least those in Magical Britain – were far less monstrous, and retained a more human mindset, despite their more questionable biological background.

"I…see." Shinji stated unsteadily, thrown off by his Master's frank admission. Truth be told, there were times when his teacher made him quite uncomfortable, but that was the price he paid to be her apprentice. Speaking of which… "This is for you."

From his mokeskin pouch, he withdrew the set of ornate playing cards that he – or Luna, rather – had found in the Room of Hidden Things, and presented it to the puppetmaster, who, being quite a collector, recognized it for what it was.

"A Mamluk set?" she murmured as she took the proffered cards, running her fingers over them. "In rare condition, too. Tell me, Matou, do you have any idea what these are?"

"…playing cards?" Shinji guessed. It wasn't as if he had any brilliant thoughts as to what else they might be…

"From the Mamluk sultanate of Egypt," Aozaki Touko confirmed. "Note the abstract designs and the lack of portraits, as well as the Arabic. And…" For a moment, the woman paused, frowning as she felt the currents of prana therein. "…enchanted as well. This set was most likely a divination tool enchanted by Middle Eastern magi. An acceptable present, Matou."

"Egypt?" Shinji echoed. Could this possibly mean a connection to Atlas? "But how did it get to Hogwarts?"

"Through Venice, and overland, from merchant to merchant, I expect," Touko noted. "From what Hijiri says, for a time, European practitioners of witchcraft did have some trade with the Near East through the usual channels, though very little was ever officially recognized. Quite frankly, their International Confederation is more of a European confederation, even to this day."

"I see," Shinji said, taking out the other gift - the book about what was supposedly the Darkest Art. "This is yours as well."

"Ah, yes, Tomas was telling me all about this volume," Touko mused, taking it and flipping through the pages briefly. "I will have to find the time to read it in detail."

Before they could go on though, their conversation was interrupted by a rapping at the chamber door.

"Enter," Touko intoned, with the door swinging open to admit what seemed a like boy around Shinji's age – a boy who the Matou scion recognized from the many ofuda training sessions he'd had with him – and by his five bone-white tails. "Ah, Kaiduka-san. I was wondering if you would show."

Kaiduka Shiosai, the five-tailed kitsune familiar of Matuso Hijiri.

"I was detained," the boy answered blandly, noting the presence of Matou Shinji with a slight nod. "Sajyou-san required additional tutoring in cursecraft."

"Combat training, I suppose?" Touko asked.

"Indeed. She is a most promising pupil. But then so is yours, Aozaki Touko, even if he is more skilled with destruction than creation. Much like Toroi-kun was once, before his unfortunate entanglement with Nōhime."

Shinji frowned.

Toroi-kun had been the name of the shopkeeper who'd sold him the Of Ofuda and Origami book, the book which adapted the principles of Onmyoudou for use by practitioners of witchcraft, allowing similar effects to be achieved using a different foundation.

But Nōhime…that was the name of Oda Nobunaga's barren wife, said to have the mind of a genius and the appearance of a goddess, yet who had been neglected in favor of his concubine Kitsuno. And she'd lived over four hundred years ago…

"You…knew Toroi-san in his youth?" Shinji asked, noting the familiar's five tails warily. If the legends of kitsune gaining one tail for every hundred years they'd lived were true, then Kaiduka-san must be nearly five hundred years old himself. "Just how old…?"

"Old enough, human," the other said solemnly. "Old enough to have seen emperors rise and fall. To have seen ideals be worn down by reality. To see treachery, ambition, and betrayal in abundance. I witnessed the Shimabara Rebellion, and how Amakusa Shiro was encouraged by the ones you called the Holy Church as a ploy for control over our lands. I witnessed the opening of Japan. And more…"

"…then, is Hijiri…?"

The fox let out a bark of laughter at the question, a harsh, sharp noise that was quite at odds with his usually serene expression.

"Matou Shinji, it is generally not considered polite to ask about a young woman's age," he said reproachfully, with Shinji wincing in acknowledgement. "But no, she is not as old as I. She is not the first maiden I have served, and I doubt she will be the last. I do wonder what the next one will name me."

"Name you?" Shinji echoed, confused. "But—"

"You know of kotodama, the belief that there is power in a name?" the kitsune inquired, eying the young human curiously. "There is a certain truth to that tenet, especially among those of us who are not human. Thus, my true name is only known to the one I serve, so that no one else might bind me. And so in their turn, each Maiden of the Tree has named me."

"I see."

"Perhaps you should get to the point, Kai-kun? Surely you did not come here to tell my apprentice of these things."

"…as you wish, Aozaki Touko," the familiar stated apathetically. He paused for but a moment before continuing. "Matou Shinji, you are from Fuyuki, yes?"

Shinji nodded.

"Are you aware of the current situation with regards to the Second Owner?"

"…you mean Tohsaka?"

"Not as much that family of hidden Christians as much as the priest who is her guardian – Kotomine Kirei," the fox half-growled, the irritation in his voice all the more startling for how rarely he showed any emotion at all. "I mislike seeing one of Japan's greatest spiritual lands under the control of one such. Once they sink their claws into a territory…"

"Kai-kun is also concerned about the fact that the priest acted as Tohsaka Tokiomi's apprentice – and that he survived the War, while his Master did not," Touko elaborated, giving the kitsune an odd look. "And how, oh-so-conveniently, the priest now seems to be the true power in Fuyuki, with the daughter being Second Owner in name only."

"That is…interesting," Shinji conceded. And more than a little suspicious. Given the circumstances, he wondered if Kotomine Kirei had betrayed the older Tohsaka during the War in order to effectively gain control over the land that held the Grail.

The familiar only grunted in acknowledgement.

"There is also another matter or two that Hijiri would like me to follow up in Fuyuki," he stated blandly. "One of which may involve the Magus Killer's adopted heir."

"Why doesn't she go herself?" Shinji wondered, prompting the familiar to look at him as if he was more than little bit slow.

"A Maiden of the Tree cannot leave Mahoutokoro while she holds the post, Matou Shinji," the fox said slowly, as if talking to a small child. "That is the sacrifice she makes for the power she wields, just as each of us make sacrifices in our roles. As her familiar, I am her hands outside the City."

"Ah."

"Given that you have been invited to the Magus Killer's funeral, I am willing to accompany you for your protection, in the event of interference by those working on behalf of the Second Owner or danger from the heir," Kaiduka continued, his words quite incongruous with his current appearance as a young boy. "You are of course, free to refuse."

Which was true enough, though Matou Shinji had had quite a bit of experience with choices that were technically free for him to choose, but which held dire consequences. For one, the choice of whether or not to accept the wand his grandfather offered to have crafted for him. For another, the choice whether or not to join Harry in the quest to seize the Philosopher's Stone. And well…all of this year, really, given the involvement of Gilderoy Lockhart, and the many times the man had volunteered him for something he found unpleasant.

But…it wouldn't be right to simply bring someone else to the funeral, no matter how tempting it was. The rules of hospitality aside – and hospitality was a major thing in Eastern cultures – if Emiya Shirou had been briefed about the Founding Families and were aware of their status as magi, then it might not be a good idea to bring a powerful familiar along. Far better to come openly and more or less unarmed (except for his wand and ofuda), and so not even present the impression of distrust.

Both he and Shirou already had a number of secrets – it was best not to add too many more into the mix, especially if Shirou was a magus himself.

The other consideration was that traveling in the company of a powerful kitsune might raise the hackles of the priest who currently acted as Second Owner, especially if Kotomine Kirei had indeed worked to seize power from the Tohsaka. A usurper, more than most, would be cautious about others seeking to claim their position, especially when those others had more of a right to the position he or she had wrongfully taken.

"I…"

"Yes, Matou?"

Shinji sighed. He didn't want to refuse the familiar, but on the other hand, if things were as delicate as he thought they might be, he didn't want to potentially make a bad situation worse.

"Under the circumstances, I think I'll decline, Kaiduka-san," the boy stated, shaking his head. "I do appreciate your offering, but…"

"Hijiri rather thought you might," Kaiduka Shiosai replied, studying the boy critically. "In that case, I would ask that you find out if Emiya Shirou has Magic Circuits, and if so, how much training he has received, if you can."

"Looking for a student, you old fox?" Touko quipped.

"If he indeed has magical potential, then Hijiri and I have suspicions as to his true parentage, given the disappearance of a certain family in Fuyuki."

"You mean the one officially described as having died in a car accident?"

"Yes, and I do feel that excuse is used too often," the familiar grumbled. "Just as others use gas explosions or weather balloons. In any case, if he does have potential and has not been trained in more than the basics, we can go from there. After all, whatever one can learn on one's own, sometimes having an instructor is best, wouldn't you agree, Matou Shinji?"