[DezoPenguin]

Originally Posted by Moczo

Hey, remember me?

Well, I know you remember this...

Spoiler for Chaos Theory, Chapter Ten:

Chapter Ten: Season of the Witch

It was a catastrophe of epic proportions. The single worst disaster that had ever befallen this world. A thing of corruption and destruction that despoiled all it touched.

"Ojou-sama has been out of the house all day. More than once…" Sella, the elder and less cheerful of Ilya's maids (not that this was immediately obvious, since for both of them the largest visible reaction they commonly showed was a sort of mild stare) murmured.

Out of the house. All day. More than once.

Horrible.

"If Ojou-sama desires it, we have no right to question her tactics in this War." Leysritt reminded her 'sister'. The two maids conspired outside the door to Ilya's bedroom, the Clan Einzbern's pride and joy having skipped him, danced up the stairs whistling, and practically leapt into bed to cuddle her teddy bear and giggle. "She is the pride of the Einzbern. We are mere failures, to be used and cast aside. Should she wish to pursue an unorthodox strategy…"

"She is not pursuing any strategy!" The elder twin snapped. "She goes out every day, and returns every night when the fighting begins! Not a single Master has fallen or even been encountered."

(It should be noted that this last was not exactly true, as Ilya had in fact encountered one of the other Masters and let him take a nap using her lap as a pillow. But Ilya had not shared the details of her daily outings with her attendants, so Sella had no real way of knowing this.)

"Ojou-sama has assured us that her outings each day, and return each night, are crucial to her overall plans," (This was exactly true, but Ilya had deliberately left out the fact that her overall plans had less to do with winning the Holy Grail War and more to do with going on dates.) "She deliberately pursues a plan she believes the other Masters will not predict, and rightly understands that our own, inferior, minds will not be able to properly comprehend it."

"Still, the Lord requested that we guide and foster Lady Ilyasviel, push her onto the right path, and facilitate her victory in the War. At the moment, we have only her word for it that she is even participating in the Holy Grail War, and… forgive me for saying as much… Ojou-sama is… rather flighty."

"Sella."

"I know! It pains me to say it as well." Sella said, with a slight (very slight, almost invisible) wince. "But our duty from the Lord Einzbern is very clear. We must speak with Ojou-sama regarding her plans, and see if her daily activities are, indeed, in the best interests of the Clan. And if they are not, we must set her back on the course to bring glory to the family, as is her destiny. If needed, we shall… we shall… … chastise her."

There was silence for several minutes.

"Perhaps in the morning."

"If Ojou-sama is in a good mood."

"A very good mood."

"And if Berserker is asleep."

"Very asleep."

Their course of very, very careful action decided, the two maids left to continue their duties. The castle was huge and would not clean itself, after all. (Honestly, you would have thought that after 1,000 years, someone would have devised a spell for that).

Though she gave no outward sign of her dissatisfaction, Sella could not help but think, Honestly… Ojou-sama and her fickle moods… truly, I have the worst of all possible lives.

***

Zouken Matou fell to his knees, gasping in anguish. Black blood flowed freely from his ears, nose, and from beneath his fingernails. His very existence could be defined as 'living pain'.

So, the point here would be that perhaps Sella was overestimating the severity of her own situation.

Still, if there was one thing that Zouken was familiar with, it was pain. Agony was his constant companion, no matter what body he took, and he knew how to focus his mind through it well enough. And so, even as his body fell to pieces, his mind worked in overdrive to discern why.

The backlash from the loss of so many familiars at once had been considerable, but nothing he could not have handled under normal circumstances. However, this particular loss had been laced with something else… a cold, aching hunger that had actually traced his connection to his familiars back to him, striking directly at his essence and attempting to devour him from the inside out. Had his core not been safely elsewhere, he most likely would have been killed instantly. As it was, his current body was most certainly cut down to a fraction of its expected lifespan; he would need to replace it, and soon.

One of his eyes fell out, trailing more of that foul-smelling black blood and small, weakly writhing worms.

Apparently, he would need to replace it very soon.

How had this happened? It made less than no sense. Assassin had played his part perfectly at the Temple. Lancer had been lured into an inescapable situation, the second sacrifice to the Grail. The weapon had attacked, as planned, eager to devour its second meal.

And then, from within the heart of Zouken's own secret weapon, she had emerged.

Caster.

She had survived. He didn't know how she had survived, but she had. More than that, she had opposed him, entered the darkness and emerged with at least some vestige of her mind intact! Even if she had returned, she should have been altered beyond recognition, warped into nothing more than a tool of the Shadow, a method by which it could expand its power and influence. And yet… she had not.

How had this happened? A Servant had entered the Holy Grail, and returned. Not merely alive but free and thriving. Under other circumstances, it might have been intriguing indeed; a new facet of the Grail's functions to explore and possibly exploit.

Under the current ones, with all his plans for the future poised on the edge of a knife, the success and failure of his life's ambitions a single error apart… it simply worried him a great, great deal.

***

Lancer tried his hardest to keep from staring in open amazement. He couldn't afford the lapse in judgment.

As hard as it was for him to admit, the Shadow… frightened him. It was simply something he couldn't comprehend, a thing that screamed into the core of his being that he could not defeat it, could not fight it, could not even touch it; to do so would mean his end, or worse.

And yet there she was; the dark woman, standing right in the middle of the worst of it, the tentacles whipping harmlessly around her. Every instinct in his body told him she should have been dead or worse. And yet she stood in the darkness, vibrantly happy and very much alive.

For the first time in his life, Cu Chulainn seriously considered just running away. There was nothing wrong with fighting an opponent you couldn't beat, but one you couldn't understand, that was another matter. And then there was that black static that played in the back of his mind as he looked at the Shadow… the whispers that what awaited him was far, far worse than death…

"Caster…" Assassin murmured. "But you were consumed."

"That's…" Lancer muttered. No way. As part of his Master's orders, Lancer had engaged all of the other Servants, and Caster was no exception… though he'd really been fighting her bizarre Master. And this was… well, not her. It kind of looked like her, now that he actually saw it, but the presence, the essence of the Servant he had tested was entirely different. She had never exactly been fluffy and happy, but now… "What the Hell is going on?"

The smile on her perfect lips was warm and calming, in contrast to the aura of wrongness she exuded. Her black eyes seemed to glitter with amusement. "Hmmmmm? Oh, yes, I believe I was consumed. It seems I've gotten better." She said. Her tone was musical, and beautiful, and wrong. "And just in time, it seems. For starters, Assassin, have you absolutely no common sense? To just throw away such a valuable pet as this fine hound is unforgivable.

"Lancer… Assassin will be nothing but food, the first part of my revenge. But you, I intend to keep all to myself. My new puppy." She purred.

Lancer fell back into a combat stance, leveling his spear at the writhing mass of darkness. "Nah. Don't get me wrong, you're cute and all, but if there's one thing I learned in my life it's that women with too much power don't make the best companions."

Caster chuckled, and it choked like glass dust in the air. "It's simply adorable that you think you have a choice."

She raised her hands, and Lancer got the impression that it might be a good idea to move.

The writhing mass of darkness surrounding her split, and split again, breaking from monstrous tentacles into tinier, razor-thin whips; thousands of them, dividing up evenly to target both Lancer and Assassin.

"Just like I taught you, my pet. You know how to do it, even if you don't know you know…" Caster purred.

"Oh, f-" Lancer said, just before the storm began.

The spears snapped out in a hail that blocked out even the waning starlight, a seemingly endless stream of black blades. Lancer's ability to defend against projectiles was extreme, but he had his limits; his spear simply could not be fast enough to defend against a simultaneous attack against every point on his body.

But he wasn't on the middle of a lake, anymore. He was on dry land and he had options.

Gathering power in his legs, he leapt straight backwards, then again, then again. His speed was vastly beyond human, and even with a forest in the way he was able to get quite a bit of distance before…

The spears came crashing down, tearing the mountain trees to kindling. No... it wasn't that they cut the trees, or tore into them. It was as if the living wood simply ceased to exist where the razor-thin blades touched it. Trees fell, cuts smooth as glass along the length of them. The rain of black blades filled the forest… but not as much as it would have if he hadn't retreated to the outer edges of the attack before it landed. He slashed aside the spears of black, but a few dozen, not a thousand. And he had to admit, he was relieved to see Gae Bolg could actually cut the damn things. He'd been worried about that.

A blade slipped through his guard, grazing his thigh. With a wince, he took another flying leap, slashing wildly at it. The cut was shallow, and thin, but the fact that such a light blow had cut at all was enough to confirm his suspicions… whatever that black thing was, it was very, very bad news. He couldn't even imagine what would have happened if he'd been caught by it on the open water; Caster might be trying to eat him right now, but he kinda owed her one.

Well… as much as he hated leaving debts unpaid, he might have to skip that one.

Back on the lake, Caster considered her options. "Well done, my pet. Hunt him down and consume him… alive, if possible, but we need to keep you well-fed."

The tendrils of darkness coiled around Caster's body like a lover's arms, and the Servant chuckled warmly. "Of course. You'll have Assassin as well. That one, I shall bring to you personally and in pieces. Now go, Lancer isn't going to just feed himself to you. Scoot!"

If a thing could be said to move 'like a plague', the Shadow did so; oozing out of the lake and into the forest in pursuit of Lancer and sustenance.

Now alone, Caster turned toward the opposite bank of the lake, where Assassin had stood. The masked Servant had vanished in the storm of her initial attack, but Caster seriously doubted he had been killed; most likely he hid among the trees even now, watching and waiting, invisible and undetectable.

Undetectable. Not un-findable.

Caster raised her arms, palms up, and said, "Ξίφος Νύχτα του Θεού." Above her outstretched hands, discs of black flame appeared, dark against the darkness.

She threw them into the forest behind Ryudou Temple, and the sound was a bit like a thousand chainsaws going violently insane in perfect unison as trees began to fall…

***

"Archer…" Rin asked again. "What am I looking at?"

The panic was clear in her voice, as much as she might try to hide it. Panic and something else… ever since the Black Servant's boundary field had overtaken the area, she had felt ill. Her head hurt, her blood burned in her veins, her muscles felt like lead. The boundary field was…

"I don't know, and it doesn't matter: we need to get you out of here so I can deal with it." Archer said, as if reading her mind. "This boundary field is sucking your life dry."

"Like Hell." Rin growled. "I'm a Master, I'm not just going to run away like som-"

"Yes, you, are." Archer said. "Right now, you're next to useless, particularly with Assassin and Caster…"

"Caster?" Rin snapped. "That thing is… no way! It's just not possible for that to be a hero of any kind! Not even an anti-hero could be so vile. You can't possibly think that..."

"Rin," Archer said, in a low, soft voice. "I need you to listen to me. Something I don't fully understand is going on here, but I have a chance to stop it. Please… can you trust me?"

Rin thought of this. She heard the urgency in Archer's voice, saw the thinly veiled fear in his eyes. And she gave the only answer that she could.

"No."

"… what?"

"I said 'no'. You clearly know more about this… about everything… than you're telling me. And I'm starting to think that's been the case since I first summoned you," Rin said. "So no, I don't trust you. How could I? I'm staying right here."

Archer considered her response. "All right, that's fair." He admitted. "I wouldn't trust me either. So we're going to do this the hard way."

"The…"

"I'm going to pick you up bodily, drag you to the steps, and throw you outside the mountain's boundary field." Archer said.

"… what?" Rin asked, not quite sure she'd heard right.

"Throw you. Kind of like a javelin, only it's you."

"… … …" Rin said.

"Don't worry. I'm good with projectile weapons. You won't die. I'll make sure you land in a bush or something." Archer said.

"… … …"

"You'll just get hurt. Between the draining effect of this sorcery and the wounds I'll be inflicting, you won't be able to get back to the fight, most likely. You'll be stuck safely outside the boundary field, while I deal with all of this madness." Archer said. "Magi heal fast, you'll be fine."

"Archer…" Rin said slowly. "Don't you dare."

Thirty-five seconds later, as Rin screamed, tears in her eyes, flying awfully fast towards a bush that didn't look at all soft enough for her tastes, she wondered why she'd ever thought this stupid war was something to look forward to.

***

Archer turned back towards the Temple, a screaming in his blood that he could not ignore. His true Master calling him to action.

But... the normal haze over his actions when performing his duties as a Guardian was not there. If that meant the situation was not yet dire enough, or the Servant summoning interfered with the process, he couldn't tell, but it meant he could face this crisis as himself. If he could deal with this problem now, while he still had his sanity, then...

Maybe, this time, my actions don't have to end in a massacre.

That was a rare thing for him, and something worth fighting for indeed.

Time to save the world, then.

***

Lancer went sprawling as the blades of darkness nicked him again.

Agile as he was, maintaining a perfect dodge rate against an enemy that could attack from any direction and seemed to be part of every shadow under every tree was a tall order. And since even the tiniest contact with the dark, twisted substance made him feel exhausted, he couldn't afford less than perfect.

At the least, his spear seemed able to do some damage. It hadn't really hurt the thing in any visible way, but it was able to slash aside the tendrils, cut the shadowy 'flesh'. He wasn't defenseless... completely.

But he couldn't win. He knew that much. Nothing seemed to do any lasting damage, the tendrils coiled around his legs, snapped from the dark spaces between every tree, surrounding, consuming...

He didn't bother to get to his feet, more 'throwing' himself from a prone position with his one free arm; not graceful, but it was movement and that was what he needed right this moment. Black spears slammed into the ground where he had just been as he flipped through the air, slamming his spear into the ground to steady himself and get back to his feet in time to slash aside the next attack. But he was being worn down, and the Shadow was between him and the only exit from the mountain; the main gate. The boundary field around the mountain would heavily resist a Servant on entry or exit, except for the main gates, the only hole in it. No way he could power through the boundary field with that thing on his tail, and no way he could kill it, at least not that he could see.

The tendrils were moving to surround him again, attempting to strike from all angles. And to make matters worse, the darkness was starting to ooze along the forest floor, a pool of infinite black that would soon leave him without even a perch to stand on.

Brilliant silver arrows struck down, igniting brilliant lights throughout the clearing and making the encroaching darkness pull back with a pained shriek.

Lancer looked up... and groaned. "If it's going to be you saving me, I'd rather take my chances with that thing."

Archer fought the urge to roll his eyes. "I'd rather have your help, but if you'd prefer to be devoured, I guess we can work with that too."

Lancer chose not to dignify that with a response. "Your arrows... not sure how, but they seemed to hurt that thing more than my spear. How..."

"Fighting a curse with a demonic lance isn't good tactics. I stuck to Holy blades." Archer said, watching as the Shadow reformed; the extended cloud of darkness coalescing into a vaguely humanoid, or at least human-sized, shape. "And even then I'd say it's not too upset."

"I don't think anything upsets it." Lancer said. "... Look, I'm not suggesting we work together or anything, but how about I wait to kill you until after we get out of this alive?"

"You heroes and your pride." Archer murmured in amusement. "Very well, if it keeps you off my back, call it a cease-fire." he said more loudly, as a half-dozen brilliant silver blades materialized around him.

"You can have a sneak preview of what I'm going to do to you when that fight you want finally comes." Archer said, and charged.

***

Caster looked at the devastation she had wrought and smiled. It really was amazing what one could do with the proper power source, wasn't it?

The forest by the lakeside had been devastated, and not one single throwing blade or curse had come from it in return. Not that it would have mattered particularly if Assassin had managed a counterattack, given Caster's raw power and defenses, but the fact that he hadn't even made the attempt told Caster that he most likely couldn't. She would have preferred to witness his death more closely, and preferably insure the pain involved in it was intense as possible, but she would accept this. There was, after all a certain glee to be found in the knowledge that she had crushed him like an insect. His death had been as anticlimactic and sudden as Soichirou-sama's.

There was a small measure of justice in that.

And now...

A silver flash tore through her mind. Not exactly painful, but shocking.

A man in a red coat, silver swords dancing around him, illuminating the darkness, tearing through the shadows the filled the sacred mountain.

No... no, her pet was...

The blue knight drove his spear forward, and something hissed as it pierced semi-solid black 'flesh'.

Caster was a part of the Shadow, and the Shadow was a part of Caster. Now, it was in distress, and the pain tore through her link as it called her to its side, seeking protection. Lancer had found an ally, and as much as she had taught her pet it was not yet strong enough to face this new threat with the blazing silver blades.

Caster took to the skies, not remotely happy with the state her new toy was in and not at all shy about sharing this fact with its tormentors.

And in the decimated forest she had left behind, a white skull briefly appeared among the fallen trees before once again fading from sight...

***

It wasn't exactly beautiful.

The swordsmanship displayed by the red knight was not the graceful beauty of Saber's otherworldly skill, nor the fierce beauty of Lancer's inhuman speed and strength. The silver swords appeared from nowhere and were ruthlessly discarded; each one piercing the Shadow's form, being devoured, and vanishing only to be replaced just as quickly. The knight had no grace, no beyond-human skill, just ruthless practicality and efficiency.

Lancer didn't honestly care; it was damn effective, and that's what mattered. He still didn't get the impression that they were really harming the bizarre thing, but the holy swords were shredding the black mass and pushing the monster back, and that was good enough.

Or, rather, it had been good enough.

"Μαύρη Φλόγα Βροχή ."

Pillars of ebon flame smashed down around the Shadow from above, tearing craters in the ground and driving back the two knights slashing away at its mass.

Above the treetops, Caster hovered, her cape spread like the wings of a bat and runes of power glowing with black light in the sky around her.

"Bad dogs." She purred. "If you can't play nicely with my new pet, I shall have to put some effort into taming you."

"Damn..." Archer muttered. Two-on-two, he was not sure of his chances, not this time. He was already cheating, tapping into powers that a Servant shouldn't have had, and he hadn't been doing a whole lot of damage. Now he had artillery to deal with too.

"You think we can take her?" Lancer asked.

"Do you?" Archer asked.

"Doesn't really matter, I'm trying anyway."

"... fair enough." It wasn't as though they had a lot of other options.

Caster descended, landing inside the Shadow, which dissolved around her into a pool of darkness that began to spread. "Now, my pet, we strike as..."

Something as black as the Shadow around her feet slammed into her back, jerking her body. She looked down at her chest in disbelief, two holes in her chest from projectiles that had gone into her back and pierced completely through. She fell to her hands and knees, blood flowing freely from her mouth and chest, her eyes wide with shock and agony.

A white skull hovered silently among the trees. "You missed," Assassin said.

Archer smirked. Three-on-two was a little bit better.

"You... you... you... you..." Caster murmured. Rather than fading away, she seemed to make everything else around her fading away... power gathering to her, drowning out what tiny bits of light remained on the mountain. Caster rose to her feet shakily, a globe of dark power encircling her, the hole through her chest already halfway closed.

"Damn..." Archer said. "You missed too."

"I see that." Assassin said, his tone somehow managing to be emotionless and yet mocking. "That cloak is partially alive, and it disrupted the course of my knives."

"Seems like she's got a major mana supply. She's healing fast." Lancer said, shifting his focus from Assassin back to Caster. "Also, she looks pissed."

Caster's black eyes were mad. There was no other word for it; she was simply and utterly insane as she turned to cast her gaze on Assassin.

"You... do you think that I would fall to your parlor tricks... you won't take me like you took Soichirou-sama... not me... never me...!" She snarled, a thin line of reddened drool running from the corner of her mouth. The Shadow snarled around her in sympathy to her madness, flowing into her wounds and accelerating her healing.

Seeking vengeance.

"I'm going to tear you all limb from bloody limb!" Caster roared, the darkness erupting from her in an explosion of power that shook the mountain.

"This is going to suck." Lancer said.

Whoa, big fight scene! Now I know why this chapter took so long to write...Nonetheless, this scene contained the customary 100% of the recommended monthly allowance of Awesome. And as a bonus we get the maids being cute and Zouken suffering (which is always fun)! So...Caster Alter can be shortsightedly smug. This is good to know. Though if they drive her off, Lancer had better keep a very close eye on Assassin or things will end up right back where they started before Caster interfered. Loved Archer dealing with Rin!

One typo in the first section; you wrote "walked him" instead of "walked in." (I might also suggest "literally true" instead of "exactly true" in the same section, but that's more of a style thing.)