"... it has to be the Holy Grail's influence," Gudao remarked as the Chaldeans started taking stock of the new arrivals.
"Nobunaga, Okita intercept them. Jeanne, anchor the rear. Marie... move up, but be ready to rush to retrieve Scáthach if she calls for help," Sasaku quickly re-oriented their forces.
"But the (Guillotine Breaker) is already..."
"Don't worry, we can Command Spell it. Come on !" Matching actions to words, Sasaku ran over to where Geronimo had fallen while the Archer and Saber quickly interposed themselves between the stampeding Phantasmal Beasts and their various occupied allies.
"Can you tell us what happened, Geron-"
*crack* *swish* Right as she reached out towards the Caster to analyze his likely injuries, instead the shaman grabbed her wrist with the speed of a striking snake and spun her around while sliding to reverse their positions like a dance, ending with the Ruler's back pressed against his chest.
And his knife pressed against her throat.
"You're not Geronimo," she muttered more calmly than she surely felt.
"A bit late to notice that, Master," the imposter commented evenly.
"... so you're one of Goetia's Demon Gods," she added after taking in what her analysis readings suggested.
"Right. But unlike Flauros I can get things done. Well, I wasn't sure about the reports about your kind's fashion sense, but what's yet another piece of intel he messed up. Now tell your Servants to stand down before someone gets twitchy."
"What, you're afraid of them?"
"No, but if an attack hit my arm, you might find yourself, unfortunately of course, suddenly losing your head."
"There's a horde of Beasts right on top of us, you know."
"Yes, that would complicate matters, if they hadn't just, well you can look ahead and see for yourself." Dragging her up onto her toes, the disguised Demon God showed her the odd sight of a phalanx of Phantasmals stopped just in front of where Marie, Nobunaga and Okita were standing. More of them were fanning out to either side, but they didn't seem particularly interested in pressing an attack.
She thought back to the Caster's Noble Phantasm, a coyote who stole the sun's tobacco. "I see. They're Geronimo's- And they must have the Grail with them somehow. I still don't see why you care, since a Singularity suits your purposes by simply continuing to exist."
"I'm not going to explain it to you humans," the Demon God sneered. "Whoops, did I nick you there? Tell your Servants to return to Chaldea."
"What?" Sasaku practically laughed. "Do you really need 'no witnesses' when you kill me? Well look at it this way, Ruby-! "
The fake Geronimo had about a moment to act, but unlike the speed with which his quarry identified him, he didn't realize his mistake as, drawing the fallen Caster's blade across her ne-
As the light from her transformation raced towards the blade holding her hostage, Sasaku also simply reached up and grabbed hold of it in the same tempo. The moment everyone could see clearly again, the knife was just about a centimeter away from its target, and
"(Three Line Formation) !"
Striking with mass, precision, speed and accuracy, Nobunaga shot the fake Servant from the front, taking advantage of the fact that Sasaku was simply physically smaller than Geronimo. About a moment later, in a reverse of the other's initial grab, Sasaku swung out and up, clearing the way for the Archer to continue pouring shots into the staggering humanoid form.
Reaching out a hand as Marie and Okita charged him, the Demon God flung out a number of deadly attacks towards the oncoming Servants. Marie dropped to the ground in order to avoid them, but Okita, practically dancing in between the hail, got in just close enough to activate her "(Mumyou, Sandanzuki) !"
...
Time seemed to slow down as a fountain of blood and magical energy burst forth from the sudden wound where the Three Thrusts had broken through the Demon God's defenses.
"Well then," he remarked with the air of one commenting on the weather. "The painful way it is."
At that moment, a number of flashes emanated from the 'sun' overhead as the Chaldeans became aware of multiple large energy signatures that had clearly been waiting on, and just answered, their fellow's summons.
"Demon God Pillars !" Jeanne shouted. "Run for the base !" Taking her own advice, the Ruler quickly took hold of the Masters and started running.
"Wait, d'Eon -"
"Don't worry about me-" the Saber attempted to dissuade Marie from coming to his aid just as he was abruptly picked up by a returning Scáthach.
As the Chaldeans beat a hasty retreat towards them, the Phantasmal Beasts abruptly started moving, spreading themselves out as, like Jeanne had warned about, several Demon God Pillars began materializing around their apparently fallen colleague and began tearing up the landscape with high-powered magical beams targeting the Servants and nearby Beasts.
"What are they doing?" Marie asked no one in particular.
"They're fighting the Pillars, of course," Sasaku replied as though it wasn't obvious.
"But wh- wait, he got you."
Indeed, as the magical girl realized on touching her throat, she had in fact been cut. Oddly enough, or perhaps not, there only seemed to be a neat slice though the section of her outfit that would cover it. Normally damage only passed through after ablating enough of the protection that it would manifest as large sections being burned or ripped off.
"I guess the barrier didn't get up fast enough," was all she commented. Taking off one of her ribbons, Marie handed it over to use as a makeshift bandage.
"What are we going to do about this?" Gudao asked as though he wasn't being hauled along in a desperate retreat from several enemies of which a single Flauros had not only previously given them much trouble, but also survived the battle.
"They're clearly worried about something, to send so many of their number," Jeanne replied. "You really think it was about the Grail? I mean they put those things about in the first place."
"Well, putting aside the odd ones like Elizabeth with Halloween and Merlin with Christmas... if only we could ask Geronimo what he had been up to while playing the neutral observer," Gudako thought aloud.
"Presumably he had access to it, and they thought naturally enough that it would be on his person," Jeanne wondered.
.
(Celtic Servants)
"Well that's really gone and fucked it all up," Caster Cú frowned while downing one of the mana potions. Of course the group had to make their way back to the druids tending to the mobile cache on foot, there being no convenient chariots to ride.
"But why would these Demon God Pillars show up now?" Bazette questioned.
"They're undoubtedly here for the Chaldeans," the Caster shrugged. "But it's unlikely they'll just let everything else keep going afterwards."
"If they killed the Chaldeans, why not leave the Singularity to continue?" Sétanta asked. "You've said they didn't care who won - obviously Chaldea excepted."
"Yeah, but if Chaldea shows up, killing whoever dropped in won't be the end of it as some other ones of them will appear soon enough."
"You knew this would happen," Cú Alter abruptly accused the Caster. "At the very least you've been holding back something."
"I told all of you about the role of the Holy Grail in Singularities," he retorted. "You're thinking too highly of me if you think I foresaw the bloody game masters would come down and start kicking people out."
"The Pillars' most likely objective is to secure the Grail," Fergus concluded. "Based on what you've said, if they secure the Grail then they can go elsewhere and set it up again."
"Where would that leave us?" Bazette asked.
"Nowhere," Caster Cú replied. "By which I mean back to the Throne etcera."
"Do you think they will beat the Chaldeans?" Cú Alter asked directly.
"Almost certainly."
"Can they beat the Chaldeans and us?"
"More than likely, given the number of signatures I detected."
"What about the group in Washington?" Sétanta added.
"Yeah, to be honest I wonder if Medb was just paranoid about them. But if anyone was going to be forced to make a move it would be them. Ironically Chaldea has the least need to worry, if I'm right anyway, since even if our hosts set up another Singularity, at least it would mean this one was resolved," Caster Cú explained his thoughts.
"That's ironic though, you're saying they would be fine with leaving because the Pillars would take the Grail and go home, but the Pillars would do that only because Chaldea would keep showing up to stop them," Bazette pointed out the contradiction.
"Well the ones here would leave, but others would see it and drop in, and the Pillars can't really afford to closely monitor any particular Singularity. If anything, I would say their current actions are born more of a grudge against this particular Chaldea than some sort of efficiency."
.
(Chaldean Base)
"I don't know how you missed this, but there's not much I can do for him," Scáthach told Sasaku after examining d'Eon.
"But that Caster's rune shouldn't have... no wait, it was Medb, wasn't it?"
"Well I'm surprised it didn't occur to you," the wounded Saber coughed. "In any case, at least I can make sure you properly receive this." Taking the large lily off his hat, the same one that he had received as a present in Merlin's Christmas Event, he handed the flower to a tearful Marie.
"Nn, I'll see you soon," the Rider said quietly as d'Eon, nodding, let go of his end of the Servant contract and returned to the Throne.
"... here." After taking a look at the lily, Marie handed it over to Gudako, as only the Masters or Sasaku could reliably keep other Servants' items on them, especially when Rayshifting back.
"Hmm, what's that you've got there?" A few feet away, Sasaku was surprised when a large coyote daringly trotted up to her with something in its mouth, which it dropped a little in front of her. "That looks like Geronimo's... wait a second, it couldn't be?"
Indeed, it looked like the Caster Servant's familiar, the lack of which might have been a clue giving away the disguised Pillar's ploy. But in any case, as it seemed certain that the Demon God had killed Geronimo, how would a portion of his Spirit Origin still be present? Frowning, Sasaku picked it up gingerly, but the... vessel fell apart in her hand to reveal -
"Wait a moment, is that a charged Holy Grail?" Jeanne exclaimed before realizing the potential implications of who was holding such an energized wish granter.
.
Notes:
That comment about Chaldean Masters' fashion sense is of course referring to how many of the Mystic Codes we get in FGO are various versions of school uniforms. Flauros (Lev Lainur) had correctly informed the other Demon Gods about how the particular Masters he was encountering looked. They are using the standard starter Chaldea Mystic Code. However, a lot of Masters being encountered by the various other Pillars are actually wearing the uniform-like ones (especially Fragment of 2004, doubtless). As you may remember, when Sasaku isn't transformed, she's wearing - a uniform.
Also she was speaking out loud to Marie about using a Command Spell. In this story, people with magecraft can use it to create a link and communicate without speaking, which is used rather commonly actually with Masters. Sasaku can't be relied on as a source of links because whenever she transforms she loses the ability to do the various things she can otherwise, so the link breaks. A broken link won't simply 'return' when she un-transforms. Of course she could communicate with Gudao or Gudako, with the Master being the source of the link, but they would have to relay it. All such links are one-to-one and two-way, and there's no network which one can broadcast over, it's more like having to pass letters around. Marie can't have a direct link to d'Eon, for example.