Disclaimer: I do not own the Fate franchise it belongs to Kinoko Nasu and Type-Moon.

Cerberus

Part V

The Sun cast its light through cold and cloudy skies come the following day, and over the crowds of people bustling through the streets of Fuyuki. They shone over the pristine façade of Kotomine Church, and through the stained glass windows in a riot of color.

The church's interior was empty, though given the time of day that was unsurprising. The courtyard beyond was as well, though in the living room of the apartments beyond, a pair of priests were holding a quiet meeting between themselves. One was a well-built, clean-shaven old man with a kindly air, while the other was a tall, dour-looking young man with more than a passing resemblance to his senior. Unsurprising, given they literally were father and son.

The younger priest, however, lacked the kindly air of his father. In its place, he carried a troubled air about him, no doubt contributing to his dour appearance.

"So," Risei Kotomine thoughtfully began. "The Edelfelt may have decided to make another play for the Grail as well. Perhaps we should have expected this…though I'm surprised they sent a branch member instead of one of their own."

"It has yet to be completely confirmed," Kirei said. "But it does seem to be that way. Master Tokiomi is of the opinion that if Cerberus truly is one of his cousins from his mother's side of the family, then this is a deliberate gesture on Edelfelt's part to underline the…illegitimate, from Edelfelt eyes, descent of Tohsaka, by contrasting it with a recognized descendant of the Edelfelt Clan."

"Hmm…" Risei hummed thoughtfully. "Only if they win, of course. If their representative is defeated one way or another, then the gesture would backfire on them. If defeated by Tohsaka, then their claims of Tohsaka's lack of worth would be exposed as hollow and meaningless. If defeated not by Tohsaka, then they appear foolish, sending a branch member and thus not nearly as capable as one born of the main line."

"A gamble then," Kirei said. "A very risky gamble, one that would be meaningless unless it results in anything but a winner's roll."

"Assuming of course," Risei said. "That Cerberus is truly of the Edelfelt Clan. Her appearance could just be coincidence."

"There is that as well." Kirei said with a nod. "Master Tokiomi has considered that possibility."

"Did he say anything more?" Risei asked.

Kirei thought for a moment. "He said that if Cerberus truly was a cousin of his," he said. "Then he would face her challenge with pride and dignity, and in so doing honor their shared lineage as magi."

Risei chuckled. "How very gracious of him," he said. "I must admit that I do not always agree with Tokiomi's decisions and opinions. In this case though, I must say that for all that his mother's relatives claim to be…elegant, Tokiomi's dignified endurance of their scorn and his modest attempts to earn their respect and acceptance put him in a better position by comparison."

"I have not heard his opinions on the matter." Kirei said. "Though I imagine he would be flattered should he hear such."

Risei snorted. "In that case," he said. "Perhaps it would be best for him not to hear what I have just said of him. As I said, I do not always agree with Tokiomi's decisions and opinions, and I must say that his pride has grown quite excessively. There is no need to feed it further with praise, well-earned as it might be. His pride as it is already presents him considerable weakness to be exploited by his enemies. If we can, let us curb it as much as possible."

"As you say, father."

Risei nodded. "In any case," he said. "Our objective remains unchanged. With his goal of using the Grail to open a path to the Root and only to open such a path, Tokiomi remains the only Master we can expect to use the Grail in a responsible fashion. Continue to assist him as best you can, and ensure his victory."

"Yes, father."

Risei nodded. "On another note," he said. "Any word on a replacement arm?"

"Yes," Kirei said, glancing at the limp and empty sleeve on one side of his habit. "It should be arriving in a few days. Master Tokiomi and I will work together to implant it onto my body, and then I should be ready to rejoin the war in earnest."

"Excellent news." Risei said with a nod. "A shame about your original arm though…I know the Lord commands us not to seek vengeance and instead to forgive and forget, but as your father…"

Risei trailed off and sighed. "No," he said. "Even that is not a good reason to go against the Lord's teachings. Though Assassin and Cerberus alike must be dealt with one way or another, do not do so with revenge in your heart, my son."

"I shall keep such wisdom at heart when the times, father."

"What's wrong?"

Irisviel pointed at what seemed to be, if Kiritsugu's eyes weren't mistaken, a fruit basket. "That just arrived by mail." She said, before holding up what looked like a letter of some kind. "This came with it."

Feeling a headache beginning to build between his eyes, Kiritsugu took the offered letter and began to read.

Dear Mister Emiya,

I would like to express my respect and admiration for your actions during the previous night. While the methodology is not something I would use, that you were able to neutralize the formidable defenses of Lord Kayneth Archibald El-Melloi with only minimal effort is unquestionably commendable. More than that, you also destroyed his field workshop in the process, and in so doing, prevented Lord El-Melloi from ever being able to fight from a position of overwhelming strength, as all magi would within their workshops.

With that said, I would like to offer gifts to further express my respect and admiration for your person. First of course, is the fruit basket this letter comes with. Second, is information I have procured over the preceding hours. Specifically, Lord El-Melloi has survived the destruction of his workshop, and while you no doubt already know this, he is also preparing to retaliate. What you may not know, however, is that he is planning to attack you at your stronghold within the Einzbern Forest. Why he would do so considering such is the center of your power, is beyond yours truly.

Should you, however, know of this already, then I apologize for my presumption. To conclude this letter, I would again express my respect and admiration for your actions during the previous night.

Sincerely, Luviagelita 'Cerberus' Edelfelt.

P.S. I can see where Illya gets it from. She was cute, but really terrifying on the battlefield.

Kiritsugu crumpled the letter in his hands. "So…that last bit…" Irisviel shakily began, having been reading over Kiritsugu's shoulder. "Does it…does it really mean that…she's a…"

"…have you checked the fruits?" Kiritsugu asked.

"Yes, they don't appear to be poisoned in any way."

"Good," Kiritsugu said, massaging his temples. "I think I need a drink, and maybe something sweet to…to, take all this in with."

Muttering to himself, Kiritsugu stalked off, Irisviel following after him after picking up the fruit basket. "At least," she hesitantly began. "We now know her name. Luvia-something Edelfelt?"

"Luviagelita..." Kiritsugu absentmindedly corrected. "Strange name…why reveal it now though, after previously using an alias?"

"…to further express her…respect, and admiration?"

"…if so, then she needs help." Kiritsugu said with a sigh, coming to a halt with his head down. "I bombed a hotel, for gods' sakes. Reduced it to rubble…if I hadn't…hadn't mellowed out over the past few years, I'd have done it without letting anyone be evacuated. Hundreds of people would have been killed…and she says she respects and admires my actions? Fucking hyenas…"

Irisviel sadly but sympathetically stared at her husband, and after a moment reached out, placing a hand on his shoulder and squeezing gently. "Kiri…" she said softly, as he reached up and squeezed her hand back.

Without further words, Kiritsugu continued on his way, followed by his wife.

"Fervor, mei sanguis."

The entrance to Castle von Einzbern exploded, not just the door or even the doorframe, but also part of the surrounding wall, torn apart by the sheer power of Kayneth's mystic code. As the clouds of dust began to clear, Kayneth walked through the ruins, and into the foyer. Soundlessly rolling along at his side, was said mystic code, Volumen Hydragyrum, looking for all the world like a gigantic, silver blob of mercury.

"I am the Ninth Head of the House of Archibald, Kayneth El-Melloi." Kayneth formally introduced himself. "Einzbern magi, I challenge you to a duel for both the Grail, and our lives."

There was utter silence, and then a flicker of motion drew Kayneth's attention. In one corner of the foyer, a CCTV camera swiveled to look at him, and causing Kayneth to smile with amusement. After a moment, he took a step forward, and then another, slowly but steadily making his way across the foyer.

And then the foyer was shaking again, as multiple explosions erupted all around Kayneth after he tripped a set of wires strung across the floor. Smoke and debris flew through and filled the air, along with ball bearings that tore apart everything in their way. But as the smoke and dust cleared, all there was to see amidst the ruins was a gigantic sphere of mercury. After a moment it retracted, shrinking down to its previous size, and revealing the unharmed Kayneth, his mystic code having deployed at incredible speed to surround and protect him from the explosions.

Given the expression on his face, he was far from happy.

"Traps?" he said with disdain. "I expected better of Einzbern. So be it then. This will no longer be a duel, it is now an extermination!"

Silently and unhurriedly proceeding through the foyer, Kayneth made his way to a nearby sitting room, where he extended an arm out imperiously. "Ire Sanctio!" he cast, Volumen Hydragyrum extending feelers of mercury in several directions. Kayneth closed his eyes to focus on what his mystic code was detecting, and then opened them before smiling as he found what he was looking for.

"Scalp!" he cast, Volumen Hydragyrum reforming in the blink of an eye before striking upwards with its feelers. Wood and stone exploded as Kayneth stepped onto a platform of mercury, which then lifted him upwards, through the hole in the ceiling and into another room, Kiritsugu Emiya standing before him.

"I've found you, rat." He said with sophisticated disdain.

In response, Kiritsugu just raised his gun and opened fire on full-auto.

Assassin stayed silent in her astral form, prowling through the corridors of Castle von Einzbern. At her Master's command, she had followed Kayneth and Lancer as they proceeded towards the Einzbern forest after nightfall, using presence concealment to the limit, until Kayneth had broken through the foyer, then up from the sitting room, to where Kiritsugu was.

She had not followed, lying in wait beneath, and was caught by surprise when Kiritsugu jumped down and slipped past moving too fast for the eye to follow. If not her superbly-honed instincts and senses, she might even have missed him.

"Master, did you see that?" she asked.

"Yeah…I think…I did." Cerberus replied hesitantly. "That was…unexpected? I've heard his family used Time Alteration, but I never managed to find out the specifics as he used it. There was no record of it."

Assassin tilted her head. "From what I can hear," she said as Kayneth jumped down followed by Volumen Hydragyrum. "It seems he somehow manipulates the flow of time within his body, using it to define a…reality marble?"

"Huh…so that's how he does it." Cerberus said, her thoughts tinged with surprise. "Clever…but also dangerous. Once the flow of time returns to normal, then relativity will take its toll as his body adjusts to the difference."

"I bow to your knowledge of magecraft."

"I'm not that good. In any case…continue to follow Lord El-Melloi, but take no action unless I command it."

"Yes, Master."

Assassin followed her Master's command, proceeding invisible and undetectable behind Kayneth as he proceeded through darkened corridors, until he entered one that was lit. It was a simple but basic trick, Assassin realized. Proceeding through the former, Kayneth's eyes would adapt to the dark, but when he entered the light, his vision would suffer for it.

Unless…he was using magic to counter it?

Assassin was about to ask her Master when Kiritsugu unexpectedly called Kayneth by name to one side. At least, Kayneth didn't expect it. Assassin, in contrast, knew this was the perfect place for an ambush.

Kiritsugu again opened up on full-auto, bullets expending themselves harmlessly against Volumen Hydragyrum. And then to Assassin and Kayneth's surprise, a bullet blew through Volumen Hydragyrum, and punched through a shoulder in a spray of blood.

"Holy shit!" Cerberus said in surprise. "That's the trick he tried to pull on me! Use an MP5 to make the enemy think that's all he has, and then fire a bigger bullet using another gun!"

"How fortunate your defenses were stronger then." Assassin said.

"I've nearly been killed or worse as a kid thanks to being soft." Cerberus darkly replied, to Assassin's surprise. "I've learned my lesson. A lesson that magi ought to learn themselves."

"That said," Assassin said. "If they did, it'd make your job all the more difficult, Master, so it's probably a good thing they don't."

"True…but I at least taught my siblings right. When it comes to fighting, you either go big or you go home. Not that my older sister needed to learn that, considering even her basic attacks could level buildings."

"I see." Assassin said.

"Continue to follow and observe." Cerberus commanded after a moment. "I doubt if this is all Mister Emiya is capable of."

"Yes, Master."

Assassin continued to follow Kayneth through the castle, explosions erupting along the way as they set off more traps. Incensed, Kayneth laid waste to the surroundings along his path to preemptively set off or simply destroy traps before he could get to them, all the while clutching at his injury and dripping blood onto the floor.

Finally, they emerged into another corridor, with windows looking out onto the forest. Kayneth turned one way, but Assassin knew otherwise, simply out of instinct. Turning her intangible head, she focused on Kiritsugu standing flat against the wall.

After a moment, Kayneth also noticed, and turned to face Kiritsugu. Assassin took a step back, widening the distance between her and the two combatants, as while nothing should be able to hurt her in astral form, it didn't hurt to be cautious.

Kayneth ranted out threats against Kiritsugu, who responded again by opening up with his MP5. This time, Volumen Hydragyrum didn't just form a single, protective layer of mercury, but a multi-layered one with greater density.

"That should protect him against the same trick from before," Cerberus observed. "And Mister Emiya has to know that. So how…?"

Cerberus' thoughts abruptly broke off as Kiritsugu fired his Thompson, the heavier bullet being caught mid-flight by a whole layer of mercury which parted and then closed in tightly around the bullet. And then…

…Volumen Hydragyrum exploded, the high-density construction simply falling to the ground in a rain of liquid metal.

"WHAT THE HELL?" Cerberus' thoughts exploded in shock and disbelief, sentiments shared by Assassin herself.

They watched as Kayneth went into convulsions, clawing at himself while gasping in what was clearly agony, and then vomited blood before collapsing prone onto the amalgam of blood and mercury. Unbidden, Assassin turned to the spent bullet lying in the pool of liquid around Kayneth's body.

"Assassin," Cerberus said. "Bring that bullet back."

"Yes, Master."

Assassin turned to Kiritsugu, assessing when to make her move. Kiritsugu reloaded his weapon, and then slowly approached Kayneth's body. Assassin turned back to Kayneth, and narrowed her eyes behind her mask.

"He's still alive." She observed. "Should I finish him?"

"No, this is Mister Emiya's win." Cerberus answered. "He has the right to deliver the killing blow, and I doubt he won't."

"Yes, Master."

And then Kiritsugu was stepping back, and opening fire on full-auto again. And again, bullets splattered away, this time in showers of sparks as Lancer blocked all of them with his spear. "Well, that was unexpected." Cerberus observed.

Lancer gave Kiritsugu a warning, before leaping away with his fallen Master held over a shoulder. "I believe this is my chance." Assassin said, as Kiritsugu rushed to a window to see.

Rushing towards the pool of liquid, Assassin shimmered back into physical form, sweeping down to grab the spent bullet as she ran past. Mercury fell in gleaming orbs from her fingers, Kiritsugu spitting out vile oaths as he realized what Assassin had done, and raised his gun to open fire.

Assassin simply danced away from his line of fire, and leaping through a broken window, landed lithely on the ground below. In a moment she was leaping into the tree line, and smiled to herself as she ran from one shadow to the next, bullets flying wide as the echoes of Kiritsugu's curses grew fainter.

"Well done, Assassin, well done." Cerberus congratulated her.

"I am pleased to be of service, Master." Assassin replied.

Nearly an hour later, and Assassin was reunited with her Master at Ryuudo Temple. Cerberus held out a hand, and Assassin raised an eyebrow. "I would remind you, Master," she said. "That my body is literally poisonous. While I can control it to prevent it from corroding or tainting objects I touch and the air I breathe, when it comes to people…"

"Oh right, I forgot about that." Cerberus said, sheepishly scratching her cheek. "Damn…you deserved a handshake and a pat on the shoulder for getting your hands on whatever it was Mister Emiya used to one-shot Lord El-Melloi. Judging from his response, it must be really something he wouldn't want people to find out."

Cerberus paused and laughed. "Can't blame him, though." She said. "Spell-casters we might be, but the same principles apply. Finding out how his mysteries work lets their weaknesses be known as well, and counters to be prepared. Wouldn't want anyone to find out about my trumps either."

"As you say, Master."

Cerberus held out a hand, and Assassin dropped the bullet into her waiting palm. Cerberus blinked, and then her eyes grew wide as she picked up the bullet and held it up, closely regarding it with her eyes. "Holy shit," she said. "This is a conceptual weapon."

Cerberus shook her head in disbelief, before slowly smiling in awe. "That magnificent son of a bitch." She said with a grin. "He used a fucking conceptual weapon to crush Lord El-Melloi's mysteries and from the look of things, Lord El-Melloi as well."

"Might I ask what a conceptual weapon is, Master?" Assassin asked.

"It's a weapon that embodies a single, specific concept, and is meant to crush any target with that concept." Cerberus said. "They're usually used against targets that can't be hurt or damaged by conventional means, like vampires or Phantasmal Beasts. They're not easy to make, or to find for that matter, and would be overkill against most targets or enemies, so they're not common at all. No one could expect the Magus Killer to have one…wait, no, they probably do, but they probably don't expect him to use it except as an absolute last resort. I get the feeling this…bullet, and others like it, are not a last resort."

"I see." Assassin said with a nod. "May I ask what concept that bullet embodies?"

"No idea." Cerberus replied. "I'll have to study it some more, and carefully too. Wouldn't want to get a backlash of some sort by being careless."

"Indeed." Assassin said with another nod, before tilting her head. "Would you perhaps have conceptual weapons of your own?"

In response, Cerberus reached down to her waist, to her dress' belt. She wore two, actually. The one on top was nothing special, but the one underneath it, it had small loops woven into its underside, loops Cerberus used to store shuriken with.

She pulled one of those out, a square dart made from iron about seven inches long, and tossed it to Assassin. "Not nearly as powerful as Mister Emiya's conceptual weapon," Cerberus admitted. "But wounds from those require magical healing to close. Without magical healing, they simply won't heal and will eventually fester and kill you."

"And the concept behind them?"

"Death."

Assassin made a gesture indicative of surprise, and with a smile Cerberus shrugged and walked off. After a moment, Assassin tossed her Master's shuriken about with one hand, and followed.

"We've got a problem." Kiritsugu hissed while pacing in an (unscathed) sitting room at Castle von Einzbern.

"What exactly happened?" Irisviel asked, sitting at the table with a steaming cup of tea at hand.

"Assassin infiltrated the castle, while all of us there was focused on, well, fighting each other." Kiritsugu said. "Me and Kayneth…no doubt she and behind her, Luviagelita, were watching and taking notes all the while. But that's not the problem. The problem is that Assassin was able to recover the Origin Bullet I'd shot Kayneth with. And she escaped with it."

"But that means…!"

Kiritsugu nodded, and began pacing again. "She'll probably figure out what it is soon enough," he angrily said. "And probably develop countermeasures. Damn it! That woman is throwing all my plans and calculations into chaos. In hindsight, the number one spot among our enemies shouldn't have been Kayneth, it should have been her."

"Well…you did say Edelfelts fought like you do…"

"Except I didn't know it at the time." Kiritsugu grumbled before taking a deep breath. "And they're allied with Tohsaka and Kotomine…damn it, at this rate they'll have countermeasures too. Damn it, damn it, damn it…"

Irisviel quickly got up, and embraced her husband. "Calm down," she said, holding him tight and pressing her head against him as he embraced her back. "I know things look bad, but I absolutely have faith that you'll somehow be able to find a way. You always do."

"…true enough." Kiritsugu breathed. "Thanks, Iri. And yeah, you're right. Just because she'll probably develop a defense against Origin Bullets, it doesn't mean Luviagelita or her allies are suddenly invincible. All that means is that I'll have to come up with another way to finish them."

Kiritsugu took a deep breath and backed away from Irisviel, crossing his arms in thought. "But first of all," he said. "I'll have to finish Kayneth."

"He managed to escape?" Irisviel asked in surprise.

"Lancer managed to get to his side before I could finish the job." Kiritsugu said. "I was about to use a command spell to get Saber there, but he retreated with Kayneth without attempting to engage. Nothing I could really do about that…though now that Kayneth is in no position to fight at all, we should take him off the board before focusing on Luviagelita. Take out an enemy that you can first of all, and all that."

"I must protest against this course of action." Saber said. "Certainly, Lancer is an enemy, as is his Master. But by your own words, Kayneth El-Melloi is in no way capable of continuing to fight. There is no need, to use your own words, to 'finish' him. I will defeat Lancer, and Kayneth El-Melloi will have lost the war. His life need not be taken from him."

Kiritsugu shot Saber a disdainful glance. "Defeat Lancer, you say?" he asked. "Killing his Master is the easiest way to do just that. And you cannot defeat Lancer. Not with your abilities crippled as they are by his Noble Phantasm."

"You dare?" Saber snarled.

"Kiri!" Irisviel protested, though she shot a pleading glance at Saber, who subsided.

"It's the truth." Kiritsugu said. "I am her Master, and I know how much her abilities are degraded by the effects of Gae Buidhe. She can't even use Excalibur anymore, not until Gae Buidhe is broken. And comparing her as she is now, Lancer has the advantage."

"Even so, I…!" Saber began, only to be interrupted by a raised hand from Kiritsugu.

"Say what you want," he said. "But don't deny the truth. And don't forget, we're all in this for the Grail. You have your wish, and I have mine. We must do what we must to achieve them. Now is not the time or place to hold back out of pointless sentimentality or ideals."

"Sentimentality, you say?" Saber snarled, and getting to her feet. "Pointless ideals? Are you insulting me?"

"Saber…!" Irisviel said, rushing to restrain the angry blonde.

"If it seems that way, then I apologize." Kiritsugu said. "But I was not. As I said, I'm just saying the facts as they are. Now if you'll excuse me, I have some things to attend to. Maiya, we need to check on some things."

"Understood." Maiya said, stepping away from the corner she was in, and following Kiritsugu out of the room. Saber ground her teeth and glared at Kiritsugu's back as he left, while Irisviel tightened her arms around Saber's shoulders to try and calm her down.

"Please," Irisviel said softly. "Don't be too mad. Kiri…he wasn't really trying to insult you. It's just that…he can quite blunt, when it comes to these kind of things."

Saber glanced unhappily at Irisviel, and taking note of her pleading expression, took a deep breath, letting it out explosively.

Damn that man.

A/N

No, Cerberus is not Luvia. She was just trolling Kiritsugu, who somehow manages to fall for it, and continues to assume she's allied with Kirei and Tokiomi. Somewhere in Finland, across timelines, Luvia is probably sneezing at her cousin using her name as an alias/to troll her enemies.

Speaking of allies though, Cerberus might allow herself to be allies with Kirei, but Tokiomi? She'd sooner die than stand side by side with that man. And on a similar note, I never really figured out how Kiritsugu avoided getting gutted by Saber with how he treats her in canon.