Disclaimer: I do not own the Fate franchise it belongs to Kinoko Nasu and Type-Moon. I also do not own the Megami Tensei franchise, it belongs to Atlus.

Zero to One

Chapter 9

"So how do we go about finding Caster and their little shit of a Master?" Berserker asked as soon as she and Kariya returned to their hideout. "This is a pretty big city, going door to door will take too long."

"I have an idea, don't worry." Kariya soothingly said, while leading the way to the workshop.

Berserker huffed but said nothing, first following then watching in silence. She did show a hint of curiosity though as Kariya spread a map of Fuyuki across the worktable, then taking out a silver goblet, emptied a vial of blood into it. "Who's blood is that?" Berserker asked.

"No one important," Kariya said with a shrug. "Just sheep's blood, really."

"…makes sense." Berserker conceded.

Kariya then took an obsidian dagger, and slitting his finger, flicked a drop of his own blood into the goblet. "Combustum!" he hissed in Latin, and Berserker raised an eyebrow as flames ignited on the surface of the blood. Looking more curious than before, she watched as Kariya wandered over to where the jar they'd taken from Caster and Saber's battlefield sat, in the middle of a twenty-pointed mandala probably drawn with more sheep's blood mixed with just a little of Kariya's own.

She watched as Kariya pulled on a pair of leather gloves, and carefully opened the jar. Then she narrowed her eyes and actually growled as she felt her figurative hackles rising. The mandala began to glow, heat visibly distorting the air around and over the jar, the slime inside bubbling with subdued malevolence.

Kariya reached inside with a pair of iron tongs, and visibly struggled to pull some of the slime out and deposit it inside a lead bowl. Then he carefully sealed the jar, before returning to the burning blood from before, coaxing the slime out with the tongs and into the flames.

So softly that she thought she was imagining it, Berserker heard silent screaming. Kariya didn't so much as flinch, instead heading to a cupola sitting in a corner. He nonchalantly tossed the bowl, tongs, and even his gloves inside, then sealing the furnace, opened the gas valves before igniting the furnace at full power.

"…that nasty, huh?" Berserker asked.

"Yeah, and I get the feeling we're going to find out where that slime came from once we find Caster and their Master." Kariya said with a sigh. "And I also get the feeling we're not going to like it."

"…well," Berserker eventually said. "Whether we like it or not, we'll just take their heads and be done with it."

"Fair enough." Kariya said with a nod. While waiting for the flames to go out, Kariya focused on the map, taking into account the scale before using a compass to draw a circle around the city. In the middle of the circle, he then placed a magnetic compass, before drawing a line in grease pencil to their hideout.

Kariya then stared at the flames, watching in silence for the next half hour until they went out, and then tossed a lodestone inside the goblet. "Sorbitium!" he whispered in Latin, and after a few moments, pulled the lodestone out. Putting a pin through a hole in one end of the lodestone, Kariya then placed it against the map.

"Whoa…" Berserker said, before clapping her hands as the lodestone moved on the map and pointed to a certain direction. "…if that isn't magic, I don't know what is."

"If you ask the magi," Kariya said while slowly drawing the lodestone over the map in the indicated direction. "It's just a mix of witchcraft and formalcraft. Nothing impressive at all."

"Yeah, well, fuck them." Berserker said. "You're no Merlin, but you know enough to get shit done, and that's impressive enough for me."

"Thanks." Kariya said with a small smile, which widened further as the lodestone began spinning. Taking it off the map, he marked the spot with grease pen, and then drew more lines to complete a triangle on the map. "And there we go. Caster and their Master should be somewhere around here."

"…I'm guessing we're not going on the hunt right now." Berserker said after a moment. "What with the Sun still up in the sky, and all that."

"Once the Sun sets," Kariya said. "We'll go on the hunt."

Berserker grinned. "Now that's what I like to hear." He said. "Still…what's this part of the city like? Just so we know what we're getting into later."

"A very good place to hide, unfortunately." Kariya said with a sigh. "It's all warehouses and factories over there, with plenty of access to the undercity's network of maintenance tunnels and waterworks. It proves that Caster and their Master have at least a few brain cells to work with, seeing as they chose a better spot than most to hide in."

"It fits them, though." Berserker said in disgust. "Going after children for gods know what…vermin. And like vermin, they hide in the dark under the earth."

"Fitting," Kariya agreed. "But don't get careless. We'll be facing them on their turf, after all."

Berserker hissed in displeasure. "…fair point." She admitted. "I'm guessing for now you'll be sending familiars ahead of us?"

"That I am." Kariya admitted.

"Thanks for today!"

"See you tomorrow!"

"Stay safe on the way home!"

Maintenance workers for the day shift at Fuyuki Tower greeted each other farewell as their shifts came to an end, and then leaving for the night, were replaced by maintenance workers for the night shift. The night shift put on their uniforms and dispersed across and up the towering proto-arcology, using either service elevators or the common stairwells to get from one floor to the next.

Unnoticed, Assassin's various incarnations shadowed them in astral form, rendering them invisible, inaudible, and even intangible to material senses. Combined with their Presence Concealment skill, it allowed them to slip through the defenses and tripwires on the lower floors, and make their way up, to the highest levels of the proto-arcology, where their quarry made their home.

The Assassins reached the upper levels quickly, but remained hidden in the service areas, waiting for the rest of their forces to arrive. Together, they would strike from two directions, and in so doing, maximize the chances of success, though casualties were expected to be high regardless.

Night deepened over Fuyuki City. The Moon slowly but steadily climbed higher across the sky, even as the golden light of urban development shimmered up from the city into a haze above, Fuyuki Tower's glass panes and metalwork gleaming with reflected light both from above and below.

Then the signal came.

"Begin." Kirei laconically gave the order.

As one, three dozen incarnations of Assassin phased through the walls from the service areas, and entered the highest apartment of Fuyuki Tower. Spanning the highest three floors and the penthouse area, this was the most protected and secure area of the tower.

The moment they left the service areas, astral forms or not, Presence Concealment or not, alarms immediately sounded across the apartment. "We have been detected." Assassin warned.

"Unfortunate," Kirei warned. "But we suspected that might be the case. Since further infiltration is out of the question, proceed to engage the enemy as planned."

"Understood." Assassin said, even as he and his fellows shifted to physical form. Then they surged forward, blades flashing as they were drawn, ready to meet the PMCs rushing at them. Other blades were thrown, cutting through Kevlar, ceramic composite, and cotton with ease, and causing several PMCs to fall back, crying out in pain.

"This will be over quickly." Assassin thought, as he charged in with a pair of sickles held low, to cut the PMC before him down from below.

Then things went to hell.

The PMC's skin turned red, his body swelling and growing, bursting out of his clothes. Guns fell with a clatter to the ground, and then with a roar, the oni punched the surprised Assassin in the face, pulverizing not only his mask but even his skull, and sending his twitching corpse flying across the foyer.

This was no isolated case.

All across the foyer, the PMCs realized they were up against supernatural enemies, for which supernatural means were needed to fight against. And so they cast aside the façade of Humanity, taking on their true forms, red-skinned brutes clad in blue and white jinbei, with a trio of horns sprouting from their foreheads, ears weighed down with long and heavy ritual earrings.

The Assassins fell back in shock and surprise, leaving ten of their number dead across the foyer. "Master," one of them said. "We have a problem."

"What's happened?" Kirei demanded.

Before the Assassin could reply, one of the oni present brandished his naginata, and pointing a finger at the Assassins, barked orders in archaic, guttural Japanese. Roaring their war cries, the oni raised their naginata, and charged.

"Guardian demons!" Assassin warned as they were forced into a battle for their very lives. "The guards are guardian demons in Human form!"

Any further conversation became impossible as a brutal melee erupted across the foyer. The Assassin parried a pair of blows with its scimitar, before feinting and kicking an oni in the jaw. Another oni nearby cut down a pair of Assassins, allowing another one of its brethren to charge past, naginata held at the ready while bellowing out a war cry.

Another Assassin brought down two oni, leaping into the air and launching poisoned blades from spring-loaded launchers under his wrists. The blades punched into the oni's chest, cutting into their hearts and introducing blood-boiling toxins directly into their bloodstream. A dagger turned two strikes from a naginata, the Assassin giving way all the while, before feinting and slipping into the oni's guard cut at its belly.

Nearby, another Assassin feinted and slipped past an oni, making to strike at the oni's back, only for the Assassin to get tackled and pummeled into bloody pulp against the floor by another oni. Another nearby Assassin tried to help, only to take a naginata through the gut for his trouble.

Not for away, the ranking oni grabbed an Assassin by the throat, and slamming him into the ground, prepared to deliver the killing blow. The Assassin with the scimitar arrived in time to parry the blow, the two of them briefly locking blades before the oni pushed the Assassin away, and grinding his naginata free in the process. Then the oni pressed the advantage, hammering away at the Assassin with powerful blows that staggered the latter back with every blow.

Realizing he could not match his opponent in a contest of strength, the Assassin gave way, dodging instead of blocking the next two blows, only to get kicked across the foyer for his trouble. Skidding to a halt in a crouch, the Assassin cut the legs out from a pair of oni trying to double-team him, and then rising to his feet, was forced to block the ranking oni's swing.

The force of impact threw the Assassin through a wall and onto his back. Shaking his head clear, he rolled out of the way in time to avoid a blow that shattered the marble floor beneath. Getting to his feet, the Assassin hissed as the oni rushed him in full blood rage, hammering away at him. Again and again, the Assassin blocked the naginata coming down at him from one side to another, feinting twice to try and slip free, but to no avail.

A third feint seemed to work…

…but the oni had predicted the Assassin's movements, and stabbing his naginata into the Assassin's belly, tore out his guts. As the Assassin crumpled to the ground, the oni pulled his naginata back, and swinging once, parted the Assassin's head from his body.

"Master, should we retreat?" Assassin – one of the twelve who accompanied Kirei in scaling the exterior of Fuyuki Tower to attack from the outside of the penthouse floor – asked.

"…that would be the prudent option, wouldn't it?" Kirei answered after a moment. "But, the mission hasn't failed yet. It's gone in an unexpected direction, but from what I can sense, your fellows are holding their own…barely."

"…certainly," Assassin admitted after another moment. "They have drawn attention their way, as we planned. And with it, the bulk of the defenders. Retreating now would only shame their sacrifices."

"This will have to be quick." Kirei said. "Kill everyone in our way, grab Zenjou and her child, then leave as quickly as possible. If need be, I will use a command spell, if you are willing to endure it."

"If needs must," Assassin said. "So be it."

At that thought, Kirei and the Assassins with him quickly covered the last few meters, and heaving themselves over the parapet, landed on the rooftop level. Speeding forward, they swept past the pool, the cabana, and the observation decks, towards the glass doors on the penthouse's ground floor.

Then the glass windows of the penthouse's second floor exploded outwards, causing Kirei and the Assassins to look up in surprise. PMCs jumped out, transforming into oni in midair, before landing to engage the Assassins.

But at their lead and occupying Kirei's attention was a pale, dark-haired woman in a similarly-dark business ensemble. The pistol in her hand barked repeatedly as she shot at Kirei mid-jump, Kirei dodging sideways before throwing Black Keys in her direction. She dodged them all, but this left her open to a sweeping blow by Kirei that knocked the pistol out of her hand.

Undeterred, she feinted before seemingly drawing a sword out of thin air, Kirei narrowly dodging a swing that would have cut his carotid open. "Magic…" he thought in passing, similarly noting in passing the strange, golden metal the sword was forged from, seemingly a short sword characteristic of North European weapons from the Early Middle Ages.

Snarling in a guttural language that sounded tangentially like Gaelic, the woman pressed the offensive, repeatedly slashing her sword in the direction of Kirei's thighs and lower torso. Kirei blocked them all with his Black Keys, noting with alarm how she was able to keep up with his speed…

"No…faster…!" he thought in shock as she feinted and nearly stabbed him in the face. "…I've gotten soft…soft and slow…"

The woman slashed twice more at Kirei's head, Kirei blockeing the first then riposting the second, only for the woman to dodge and then counterattacking, kicked him across the roof. Kirei landed on his hands, somersaulting to break the force of impact, and coming to a halt in a crouch, looked up with clenched teeth.

Every last one of the Assassins he'd taken with him were now dead, and the guardian demons were closing in.

Or they should have been. The woman though, gestured for them to leave, and then brandishing her sword in a low guard, gestured at him to come at her.

Snarling at the wordless taunt, even more so as the guardian demons left as though thinking him of no further trouble, Kirei leapt forward to attack. The woman leapt forward to meet his charge, and slashing as though to carve Kirei's head apart.

Kirei dodged low, only for the woman to dodge a fist that should have splattered her head across the nearby pool. Instead, an elbow slammed into his side in the next instant, followed by another elbow to his jaw. Recovering quickly, Kirei counterattacked, the woman dodging another punch, before he dodged a punch to his belly and another slash at his head.

Black Keys flashed into existence and the woman dodged a blow that should carved her face open, then a swing that would have cut her legs to pieces, and riposted a third swing aimed at her thighs. Kirei parried the riposte, only for the woman to press the offensive, slashing again and again at Kirei's torso and head, Kirei parrying and dodging slashes beyond count before feinting and leapfrogging over and getting behind her.

Hissing in surprise, the woman fell back to avoid Kirei's counterattack, through the penthouse doors and into the interior, Kirei pressing after her. With something like a hint of respect on her face, she riposted Kirei's first blow, Kirei dodging the riposte, then its follow-up, before counterattacking again. The woman dodged blows aimed at her torso, head, and thighs in quick succession, before spitting out a Gaelic-sounding word while simultaneously slashing at Kirei.

The golden blade carved through his Black Keys, only Kirei's instincts allowing him to avoid getting carved up like them. As it was, it left him open, the woman grabbing an arm to pull him in before kneeing him in the belly. Kirei gasped out in surprise, but kicked the woman away with a boot to the chest before she could gut him.

Priest and PMC slammed hard against the walls with enough force to flake plaster and crack concrete, and then both were charging at each other. Kicking off the ground, they launched at each other through the air, the woman's sword aiming to skewer Kirei through the heart. But Kirei twisted through the air at the last moment, and getting the leverage he needed, kicked down, making contact with the woman's torso, even as two command spells flashed and vanished.

The woman plowed through no less than five floors down, the force of impact rupturing concrete, steel, and aluminum as though they were cardboard. Kirei landed on his side and rolled across the floor, coughing and gasping, before he forced himself up on all fours. Shaking his head to clear it, he looked around, and knowing the guardian demons would be on him soon, rushed to where the master bedroom should be according to the floor plans they'd acquired.

There was no guarantee it would still be, as the floor plans dated to before the apartment had been occupied, and Aoi Zenjou could have redecorated, but it was Kirei's best chance at accomplishing his mission. Aoi or Sakura Zenjou, he could probably only get at one, before using his last command spell to escape (his father could just give him more anyway).

At the very least, this mission wouldn't be a complete failure.

And if God smiled on him, mother and daughter would both be there.

Then his mission could be completed in full.

Tearing through a security door, Kirei emerged into an antechamber, where his eyes widened in surprise.

Aoi Zenjou was there, cowering behind a makeshift barricade made from an overturned couch. But that wasn't what surprised Kirei. He knew little of his master's ex-wife, but he knew enough to know that she was a soft and weak-willed woman who lacked resolve and resilience. So much so, that the shotgun in her hands, aimed shakily at him, threw him into a loop.

Then she fired, and Kirei cried out as he took a load of buckshot to the chest, neck, and chin. The reinforced, bulletproof cloth of the habit he wore kept any of the lead shot from penetrating, but the force of impact still threw him back a couple of steps. But the habit was thinner around his neck, the cloth shredding and leaving the flesh beneath vulnerable, while his chin was completely unprotected.

Aoi fired again, and again, and again, Kirei blown off his feet with the fourth shot. Shakily approaching, she fired a fifth time as Kirei stirred, and then getting into close, fired her last round right into his face, shattering his skull and smearing blood and pulped flesh and brain matter across the ruined floor.

Heaving and gasping for breath, Aoi staggered back, the shotgun falling from nerveless fingers to clatter against the ground. Falling to the ground, Aoi cowered against the barricade, staring fearfully at the corpse of her ex-husband's apprentice, her body shuddering in shock and revulsion at having killed a man for the first time.

"Well, isn't this a surprise?" a familiar voice asked.

Aoi jolted and looked up, Security Chief Morgan arriving but having cast aside her Human façade, her once professionally-styled hair now rough cut and bound by crude leathers, while her business ensemble had been replaced by rough furs and linens. Totems made from carved rock, wood, and semi-precious stones hung from her wrists, her ears, and around her neck, while a short-bladed golden sword hung from a rough harness at her hip. No…not Security Chief Morgan…not anymore…not in this state…

"Though I suppose it shouldn't come as a surprise," Morrigan, Goddess of Crows, Prophecy, War, and Death said with an impressed smile. "How many times have I seen it before, after all? A mother, pushed to the brink to defend her children, bringing forth fury to put hardened warriors to shame…"

Morrigan paused, crouching down next to Kirei. "…he was a worthy opponent, you know?" she mused aloud. "Not even close to my beloved Hound, but enough to defeat my Human guise. And while your victory was due to catching him by surprise, still, his life belongs to you. After all, did you not take up a weapon by your own will, in anticipation of the eventuality of the enemy reaching your door?"

Dipping her fingers in Kirei's blood, Morrigan rose to her feet, and then approaching Aoi, firmly lifted her to her feet. "First blood you have taken, Aoi, daughter of Zenjou." Morrigan formally said, and using Kirei's blood to draw runes of courage and fortitude onto Aoi's cheek. "Steadfast amidst the fires of battle you have stood, and emerged victorious. Regret it not, for it was your life or his, and by your own will and actions, have you kept yours. Savor your triumph. Feast while basking in the light of the days to come. But remember, and never forget: all men must die, sooner or later. Until then, live, and grow strong."

Leaning forward, Morrigan kissed Aoi on the forehead, blessing her in recognition of her victory on this night, of spilling first blood, and becoming a warrior in her own right. Then stepping away, she swept her fur-lined cloak over Kirei's body…

…and with the croaking of crows, Morrigan was gone, leaving naught but black feathers in her wake, and taking Kirei's body with her.

"Hey, I know you." Kariya said, pointing a finger at the little girl he and Berserker found wandering in their chosen hunting grounds. "You're Rin Tohsaka. What are you doing here?"

"How do you know who I am?" Rin demanded.

"I knew your mother, that's how." Kariya replied. "In fact, I was her childhood friend."

"Oh…um, sorry, I didn't know." Rin said glumly.

"…what are you doing here, Rin?" Kariya asked again.

Rin fumbled, stepping from one foot to the other. "…my friend…Kotone…" she mumbled. "…she disappeared…but I used magic, you see. And I found that she was going here…and there…"

Rin waved in a vague direction, which Kariya looked in before looking back at Rin. "…does your…father, even know you're here?" he asked.

The little girl didn't answer, nor could she bring herself to meet Kariya's eyes. The man palmed his face. "…why am I not surprised that Tokiomi is so careless as to let Aoi's daughter sneak out and wander around on her own…no, worse than that, to actually go after a Servant and their Master of all things?" he thought to himself.

Shaking his head, Kariya sank down next to Rin. "This is a bad place, don't you know?" he said. "And it's going to get even worse over there. You should leave, go back, back to your house, where it's safe."

"No, I won't!" Rin exploded. "I can't! Not until I save Kotone! I don't know what it is, but something bad is happening to her! Or will happen to her! I won't let it! I won't!"

"…but," Kariya began, before shaking his head and getting to his feet as he thought better of it. "No…never mind."

"…what's your name, anyway?" Rin asked.

"…Kariya Matou." Kariya replied after a moment.

Rin blinked, and then smiled for the first time since they met. "Do you know Old Man Matou?" she asked. "He's daddy's friend."

"I know him." Kariya said. "Though it's…complicated."

"You're a magus too, huh, Mister Kariya."

"…I guess I am." Kariya said after a moment, to avoid complications, and then he sighed. "Alright, I suppose I can't make you turn back. Besides, sending you back on your own might not be safe, and I can't exactly keep going on my own, so I can't send Berserker with you."

"Berserker?" Rin asked, and then looked at the blonde woman next to Kariya at a gesture from the man.

"Hey there, kid." Berserker said with a grin. "Nice to meet you."

"Um…hi, it's nice to meet you too!" Rin shyly said.

"Anyway," Kariya continued with a cough. "We're going after the same people who took your friend, so you might as well come with us. On two conditions: one, you stay close. Two, you do anything and everything I tell you to until we're done. So long as you do that, I'll keep you safe, and we – including your friends – can all get out of this with no problems. Can you do that?"

"I can!" Rin said with a nod. "And okay!"

"Great…" Kariya said with another sigh, and sharing a slightly-concerned look with Berserker. "…now then, let's keep moving."

And here's to hoping I'm not making a mistake.

A/N

Kirei and Assassin make their move, and as might be expected, it goes FUBAR. Though at least they went out swinging, Assassin giving as good as they got against guardian oni, and Kirei even managing to defeat Morrigan's Human guise. Lancer – Cu Chulainn – is likely to have a fit if he ever found out, considering his relationship with Morrigan.

Of course, is this really the end for Kirei?