(Artoria Pendragon)
I suppose this is far enough. Truth be told, it would be nearly impossible for either of them to get back to the Clock Tower after having run out this far out into the foggy areas that had been encroaching on London from the Singularity boundary. Looking around, she could tell that the environmental mana freed by the slow dissolution of the space's reality this far from the center would represent lethal levels for unprotected humans.
They're lucky that all the Servants running about meant Nursery Rhyme simply wanted them out of the way. Of course, that might take the form of 'being dead' but it was far more likely that, stuck indoors and unseen as they were, the humans were instead in a state similar to the archetypal cat that went unobserved while in a box. Which was to say: the World would decide, and it always picked the historical outcome when possible.
She stopped, readying her weapon as Mordred came into view. Once the two Sabers made eye contact, as though by mutual consensus, their duel began without any need for fanfare or pronouncements. Artoria noted idly that Mordred was wearing a second sword, apparently more decorated than the Clarent she openly brandished, on her hip.
An interesting choice, since Servants could generally pull things like that into hand from Inventory. Perhaps that was the one she had used before 'obtaining' Clarent? If so, it was an odd affectation for one wielding a Holy Sword equivalent. Things on this side seemed to have become overly complicated before the end, but ironically it was pointless to try and work out those things with Mordred, who had likely been summoned by the World specifically to play the role of countering her intrusion.
Before either side spoke, or done much other than 'agree' that their battle had begun, Artoria began feeding magical energy into her dark weapon which drank greedily. Unconsciously shaking her head, Mordred followed suit seeing the direction that their duel was headed in.
Having been forewarned about the differences from the sword facing her, Clarent, and the wielder's two techniques of (Crimson Lightning) and of course (Clarent Blood Arthur), Artoria didn't intend to use her full Noble Phantasm to clash with the last of those. Instead, once she saw Mordred had decided to mirror her, the dark Saber quickly unleashed whatever she had already charged into her sword during the earlier 'chase' period.
(Mordred)
Mordred felt a moment of annoyance when her father attacked almost the moment the two began preparing their Noble Phantasms, but the red Saber's initial thought that she might not have been taken seriously were proven wrong when, in response, she loosed her attack from Clarent right into Excalibur's energy blast. Without having been able to fully focus herself to perform the ultimate anti-Artoria attack, it became apparent that she was on the losing end of their current quickdraw exchange.
So, even she has to reckon it a serious threat, Mordred thought with some satisfaction while preparing to take some corrective action. The first one to move would be at a disadvantage, but as things stood, Artoria's ploy of going straight to a direct clash of brute force was working because it forestalled the Mordred's ability to apply her most obvious conceptual advantage.
Ironically, the least obvious but best way to get out the bind was to actually go backwards. Beams of fired magical energy were not like lasers, and by moving away from their source, the energy coming in to either side would be at a lower density and thus much easier to break through. To double up on this effect, Mordred also drew down her own energy output, meaning at as the opposing beams now met closer to herself, some of Artoria's energy was being wasted into the surroundings, tearing up the ground and structures or just shooting off into the sky overhead.
I need to get out, break line of sight, and then prepare for a strike that'll do her in fast enough that she can't get out, Mordred planned mentally while backing off, being sure to keep her footing steady since the two of them were still essentially directing a river's worth of energy at one another.
(Artoria Pendragon)
While one might think a clash of Holy Swords would be far removed from the clash of metal blades, some general principles still applied. Namely, pressure in the bind. Unsurprisingly, Sabers equipped with Holy Sword-type Noble Phantasms could sense this critical information when using such weapons on one another as easily as when using a conventional weapon set.
And at this moment, she could tell that the pressure from Mordred's side was shifting. Decreasing, sure, but in a controlled manner. Instinctively, Artoria knew her opponent was going for the disengage option, at least partially because the dark Saber had done a quick release from her Sword to seize the initiative.
There it is.
Artoria drew down slowly on her sword as Mordred executed a series of backward hops, allowing some space for the surrounding mist to interject itself into their duel.
Ah, that's rather clever, Mordred's opponent had to concede, realizing that instead of attempting a more direct action, the red Saber had decided to use London's unusual topography to dissipate Artoria's attack since mist-affected distances effectively became much greater. As a result, Mordred's defensive needs were much lower, and simply throwing magical energy at her was becoming an increasingly inefficient manner of attack.
Making use of the distance from their beams' meeting point, Artoria stopped her attack, quickly moving sideways before Mordred could respond by shifting her point of aim. In that blink of an eye, the two Servants were now completely separated by a maze of London's buildings and a sea of thick energy-laden fog as both swords fell silent.
... we might not actually be able to re-engage if the space shifts too much. She might have thought it a possibility, but nevertheless kept her weapon ready to go. It just didn't seem likely that their mutual fate would end in such a lameduck draw, even if it was probably about time for the Singularity to start ending all around them.
There was only a brief moment of warning, but it was enough. Slightly to the left. There.
"Swallow the lightning, (Excalibur) !"
Mordred's red-hued attack was stopped at the last second by the roiling darkness, a perfect parry. If the other one had come a bit closer before unleashing her attack, it might have connected with devastating effect but in the process of such a close defense, Artoria had gained the upper hand in terms of efficiency. Doubtless Mordred had gained some support from the Chaldeans, but of course Artoria for her part had been able to draw deeply on Sakura's own reserves before setting off for the duel.
With neither side being able to resupply, it had to come down to either a surprise or efficiency in action, and right at this point -
*crack*
"Gah?!"
*ka-boom*
A fine, practically needle-like beam forced its way through the meeting of Excalibur and Clarent's energies, passing through hardly deflected and reaching out to explosively pierce Artoria's black armor. Fortunately for her, a substantial portion of the surprise attack was wasted, going through Artoria's body and backplate while the beam itself only expanded from the initial near point-like impact to an exit wound about the thickness of a finger. The rest blew away some portion of the background that was hardly relevant in comparison.
(Mordred)
She could only sigh as her father's attack suddenly faltered and then cut off.
If I had missed with that... granted, the signature of someone at the King of Knights' level was not easily mistaken, but of course there was no guarantee that even a very concentrated attack be able to reach her while threading the needle straight through the chaotic clash of Noble Phantasms.
The explosion behind Artoria only confirmed her success, though Mordred couldn't help but grumble while looking at what was by now just the grip portion of a shattered sword in her left hand. Walking up to where a stunned Artoria lay bleeding on her back, the homunculus casually tossed the hilt at her feet so the human could get a good look at it.
"I already know it's a copy made by Emiya," the downed Saber mumbled. "I hope you didn't expect me to be impressed."
"Screw what you think," Mordred retorted, spotting and quickly kicking a fallen Excalibur away from her opponent. "This battle goes to m-"
*twitch*
*splatter*
At that brief moment when her eyes turned to the Holy Sword, a small motion borne of intuition was all that stopped the ray from directly piercing her Spirit Core. Bringing Clarent around in a panic, Mordred blocked Artoria's second attempt to kill her with Rhongomyniad. The red Servant quickly brought her weapon around as the dark one quickly rolled to the side, picked up her Excalibur and rose up into a perfect stance.
"Not very good with a lance when you're a Saber, huh?" Mordred taunted her as it seemed neither party was going to rush into the attack like their first two engagements.
"It certainly had a good matchup against you," Artoria replied calmly. The two simply looked at one another, totally out of range.
...
"You're empty." Mordred stated flatly. Her own wound was probably the more grievous of the two, but on the other hand, she possessed (Battle Continuation). However, blasting away with Clarent would at best result in her totally running out and disappearing immediately.
"So are you." Artoria's stance was unwavering, but it appeared the calculus on her end was similar enough that neither wanted to be the first to move.
Mordred took a breath, keeping her eyes on Artoria the whole time. "I hope you two aren't going to interfere?"
"Hm, you shouldn't have been able to detect me though?" A small girl in black emerged from the mist as though it had abruptly brought her into being. "My big sis only wanted to watch."
"Ah, Jack, you shouldn't have responded," Nursery Rhyme showed up soon after, still in her blue uniform. "She was just guessing."
"It was your signature that give it away," Mordred shrugged.
"... are you just going to stop here?" Rhyme didn't seem worried at all, which was quite reasonable given the circumstances. "Surely you can't be satisfied with such a conclusion."
"Why does it matter to you?" Artoria frowned. "I thought you'd be over with the Chaldeans and their battle."
"I'll hear about it from them later, I'm sure. But your duel, no one else will be able to see it, to record it." As it to demonstrate, Rhyme brought up a large leather-bound book with no external markings.
"Hmph. Well then feast your eyes on this !" Mordred charged.
l
(Chaldea, Fifth Hall)
"Here it is," At last, Siegfried pointed Anaz's attention towards what looked like a rough painting sitting quietly on the wall space between two bunks. "I doubt you've seen its like."
Scrutinizing the object in question, she hadn't. A casual glance before they had turned aside to examine it suggested a child's art project, if perhaps a bit larger than normal. However, a closer inspection gave her a very different impression thanks to the unusual features laid before her.
"It wouldn't happen to be drawn by one of your children?" the human asked the homunculus as part of thinking aloud. Siegfried raised an eyebrow, impressed. "No."
There was a brief moment before she noticed that the centerpiece subject, a yellow cup, had a lustre of not just metallic yellow paint, but actual gold leaf. And that's when it clicked with something she had seen from her research into Georgios for the Masters.
"It's an icon," she exhaled upon this realization.
"An understandable conclusion, but no," Siegfried replied, this time amusement evident in his voice. "Understandable because they certainly resemble those, but incorrect as these are at most of historical value. As an illustration, that is."
She looked at the figures seated on either side of the item which she had easily identified as a Holy Grail or some fragment thereof. Based on clothes, hair and accessories, quite a few of them were known to her already. "Einzbern, Tohsaka, Emiya, Matou," she said while indicating each one. "And then there's Chloe, Saber, Sasaku and Artoria. But I don't know the one next to Matou."
"That's Medusa," Siegfried informed her. "This is in the same group as the first work of this type; it's called 'The Four Houses.' Though they are the start of a narrative series, you might be able to guess that the particular event illustrated here never actually occurred."
"That seems a rather awkward admission to make out in the open," Anaz muttered apologetically. But Siegfried chucked.
"The first thing children learn is not to take these literally. In any case, this helps show some of the relationships between the individuals present by their relative positioning, which is consistent across all of these except newer ones, like this, which add Artoria. Thus, you have Illyasviel-Chloe-Tohsaka-Kojirou-Sasaku-Emiya-Matou-Medusa-Artoria."
"Why is Artoria on the far right, instead of next to Illyasviel?"
"She is next to Illyasviel, the perspective is actually from in between them. The whole image is rather distorted, like a fisheye lens, I believe; while they might initially look to be seated on either end of a long table, there's a few things like the lines on it that show it is actually a circular one. Though of course, the individuals are not distorted the way the table is. Ah, this one here is the second, series-wise and chronological."
'This one' depicted what looked like a small skirmish, though she doubted that the image was intended to be numerically accurate. The left side showed only ten figures, with Kojirou clearly depicted in front, followed by three groups of three. Going off their hair color, Anaz could guess that the bottom group with spears and the one immediately above them apparently holding fire were homunculi. The third trio were most likely Emiya, Matou and Tohsaka.
The ground-bound figures were facing off against another group of similar size and composition, though their opponents' lowest group had halberd-type weapons. However, what was most interesting was the upper half. Among the clouds, a trio on the left were fighting against a number of only vaguely drawn opponents.
The Four Houses' were thus represented by Sasaku throwing black iron spears as well as Medusa with a polearm and Chloe shoowing a bow - that group was backlit by a mere sliver of a moon. On the right side, appearing indistinct despite being shown under a full bright sun, a number of blurry, almost mist-like figures wielded lightning bolts like throwing spears. Additionally, while the lower halves of the left group were obscured by clouds in front of them, their enemies were apparently standing on top of tree branches, the plant growing from the ground all the way up. In contrast, a vine impossibly grew up the left side of the piece sans support.
While the fighting might have only just started on the ground, the situation above suggested heavy and prolonged combat; Medusa was covering her two fellows with her weapon while on the other side some of the misty figures were leaning on their lightning spears after having been pierced by spears or massive spear-sized arrows.
"I see..." Anaz had, by this one image, more fully understood the plan which the Einzbern had been working on. And how the summonings of Chloe and then Sasaku, and now the reappearance of Emiya Shirou fit into their odd mythology. In short... "Does integrating the Grail System with the Grand Aria System allow you to summon anyone, dead obviously, that has a significant role in your 'national narrative' then?"
Surprising her, Siegfried shook his head. "We have no way to prove that it could create any records at the Throne-level. Quite the contrary actually, Emiya said he didn't have one there."
"Didn't you also tell me that he said it was in the Grail instead?"
"So he said, but we can't prove that. The Grand Aria may support and feed the Grail System, but we can't control it and summon whoever or whatever we want."
"Hmm." She looked again at the pseudo-icon. "Honestly, I would've guessed it was too late to try creating anything in the present day, but..."
"Oh I agree with that," Siegfried paused and looked thoughtful. It seemed that they had both also concluded-
"If in the future there are enough of you to create a record, then... the Grail is similar to the Throne or Root in being connected to all spaces and times, isn't it? Actually from what the original Chloe suggested, it only has to occur once in some branch sometime and potentially anyone can access it anytime provided it doesn't lead to a paradox or causal loop."
"If so, that would imply we're not the Chaldea that succeeded, since we've encountered Emiya out 'in the wild' so to speak."
l
Notes:
There will be no casual loops. However, a cause might be from another branch, or from the 'future' in another branch, or the past of one which was eventually pruned. But no loops.
Since there's branches, you might have already guessed that a form of 'many worlds' is true, however the World does not just create new branches for any/every stochastic event - so even before the pruning phenomenon comes around, there's a Copenhagen interpretation-like mechanism when a branch split does not result in two sufficiently different (ie: 'interesting in different ways') outcomes.