In combat, the concept of 'compatibility' exists.
Take Prelati, for instance. Though arguably superior in skill to the degenerate Zouken, he was utterly crushed due to the poor compatibility between illusionism and magecraft involving familiar insects. Another example—though it pertains to older settings—is how Merem Solomon and Gransurg Blackmore, by pooling their strength, could theoretically bypass the guard of Altrouge, an existence encompassing a Beast of Humanity, to execute an assassination. Such feats fall within that category.
The Mystic Eyes of Death Perception are an overt manifestation of this, granting the user an absolute conceptual advantage—'Death'—over all objects and lifeforms. Even Servants, for the most part, are bound by the laws of affinity.
Naturally, I have my own affinities as well.
Fundamentally, I handle enemies by using my superior information pool to predict a Servant's movements, then striking with a counter or preparing a specific defense based on those records.
Preparing specific provocations just for Berserker-class Servants, or embedding Sun Runes into puppets to turn them into suicide bombs—these were parts of that strategy. Even countering Lev's summons by predicting his intrusion and using the Impure World Reincarnation was a facet of this tactical calculation.
Moreover, the Six Paths of the Rinnegan compensate for my relative lack of raw firepower and mobility. If I had to categorize my position, I would be considered an 'All-Rounder.'
However, if you were to ask if being an All-Rounder means having no weaknesses, the answer is no. My primary concern is, ironically, firepower.
One might argue, 'You literally drop Shattering Stars and nuclear bombs; what do you mean by firepower?' But those are strictly last resorts. Using such means against the masterminds of a Singularity is essentially a desperate 'trump card' thrown when there's no tomorrow. If they fail to finish the job, everything thereafter is left entirely to luck.
Naturally, Servants who cannot be suppressed with standard firepower—excluding those nuclear-level trump cards—pose the greatest threat. Prime examples include the trio of kings from the Fourth Holy Grail War.
In Iskandar's case, without the support of Boudica and Spartacus, a strategy tailored specifically to counter his legend, and Iskandar's own sense of sportsmanship, I would have eventually lost. Artoria presents a problem with her unique Instinct and an absurdly high-output Noble Phantasm that cannot be absorbed by the Preta Path; a confrontation with her would inevitably devolve into a muddy brawl of who can land a fatal blow first. Of course, if she brings Avalon, I lose unconditionally.
…And then, we have this trickster before me.
A Servant possessing an insane Noble Phantasm that implants bombs into people or objects. Furthermore, with his Caster aptitude, he projects himself into ball-jointed dolls to move about, making him exceptionally difficult to pin down.
Ordinarily, 'hit-and-run' style tricksters aren't my match.
If their specs are higher than mine, I simply crush them with force. Those who rely on skirmishing tactics usually do so because their base parameters are lacking, or because such tactics are deeply ingrained in their very nature.
The former applies to Heroic Spirits of the Assassin class; the latter applies to the likes of Kiritsugu Emiya or Kayneth El-Melloi Archibald during the Fourth Holy Grail War.
But I possess too many methods to seal such tactics.
Shinra Tensei and Bansho Ten'in essentially invalidate cover and evasion. The Preta Path's Seal Absorption forcibly shuts down magecraft attacks. And then there is the Animal Path's summoning, which allows me to simply overwhelm through sheer quantity.
"Hellooooooo!? Ah, come to think of it, I already greeted you! But right here, right now, I'd like to do it again, again, again! I am the show host, Mephistopheles, here for the magic show that will dissect you, YOU! From this moment on, I shall slice you, the intruder who forced your way into this mansion, into Ka-WA-II star shapes! Like this, and like that!"
However, I say this with total sincerity: out of all the enemies I've faced so far, I have never met one who grates on the nerves quite like this.
There was that one guy from the Mages' Association who tried to threaten my family, but since he's beneath consideration... in terms of sheer annoyance in a pure 'fight,' it was like looking at myself when I was fighting Vlad III.
"Oops, that way is a traaaaaap!!! Ha-ha-ha-ha-ha-ha-ha-ha-ha-ha!!!"
"…That's a disgusting laugh."
"Oh, should I change my laughter then? LOLLLL! How's this? Doesn't it feel young and 'Gen-Z'!"
"Dammit, did the information backup get corrupted because of those Demon God Kings… that slang doesn't even exist in this era yet, you son of a bitch!"
"What does it matter! I am a clown, a laughing clown, a joyful clown, a mad clown!!! A clown must bring laughter, laugh out loud, and kill with laughter anywhere and anytime! So no matter where I plagiarize my terminology from, I'm innocent, innocent, a delightfully innocent acquittal!!!!"
Seven times now, he has cackled and swung his scissors playfully, only to be pulled in by my Bansho Ten'in and shattered. Though I could easily distinguish with my Rinnegan whether the opponent was a ball-jointed doll or the real thing, his constant popping up to detonate bombs underfoot or sending wraiths for ambushes was certainly wearing thin on my patience.
'Tch, I should have pushed a bit harder at the start to make the dolls self-destruct.'
Whether he received an information backup from Goetia or not, Mephistopheles seemed aware of the suicide-bombing puppets I used to wreck Vlad III. He gave me a momentary, serious look, before reverting to his mad clown persona, hurlings various foul insults, and fleeing.
…And then, he appeared again.
"A demon has arrived! A demon is here! The demon guard of this delightful, boring, and perpetually unhappy mansion has made his grand re-appearance! Ordinary uninvited guest Master, please exit! I'd like it if you would pleeeease depart following the guard's instructions…!?"
No matter if I blew him up with the Asura Path, gripped him with the Animal Path, or crushed him with the Deva Path, he kept reappearing.
By now, I had figured out the pattern and was using pre-summoned beasts to fight in my stead. Perhaps because he had run out of ball-jointed dolls, the relentless offensive finally paused for a moment.
Of course, that didn't mean the interior of the mansion was safe.
As a mansion occupied by a Demon God Pillar, its interior was naturally filled with malice. Rooms designed for rest were instead packed to the brim with various wraiths and undead.
Zombies and specters began to leak out and roam the halls as if the mansion were generating them according to some set rule. Whenever I used my abilities to clear them out or fight Mephistopheles, they would sense it with eerie precision and lunge at me with venomous intent.
While they weren't strong enough to actually harm me… having such bothersome gnats buzzing around was incredibly stressful.
[…The sheer quantity of undead is staggering. This rivals a catacomb with a thousand years' worth of accumulated grudges.]
"Now that I think about it, the catacombs in France and Rome were all owned by the Atlas Academy," I replied to Romani's voice.
Though the communications had lost their role as a radar for detecting prana due to the interference from the Demon God Pillar, the Chaldea link was still a necessary window for obtaining real-time status updates on the Singularity and info on others. Above all, I felt like my brain would rot if I couldn't at least talk to someone in this Singularity.
"Anyway, it should be about time for an allied Servant to show up… The scale of this Singularity isn't so small that the World fails to recognize it, is it?"
[That's entirely possible. Regardless of its danger, the influence of this Singularity itself is barely half that of the last Sub-Singularity.]
"If my luck is bad enough, I might end up filming a solo Holy Grail War."
[With Mephistopheles and the Demon God King playing the villains?]
"…Don't say such horrific things. I'd rather blow up the Singularity than go on a date with that hideous pair of tights."
Just then, with a clattering sound, another fake Mephistopheles revealed himself.
The demon, who threw a bomb implanted in a zombie corpse the moment he appeared, let out a bizarre laugh as I deflected it with Shinra Tensei.
"Oh? Oh-ho-ho? It's naaaauuuughty to reject a clown's welcoming greeting so heartlessly!"
"What insane country considers throwing a bomb a 'welcoming greeting'? Even a Viking wouldn't go that far."
"Aha! My bad, my bad~! That was a demonic mistake~! Ehehehe… I might get scolded by my employer for this. In that case, there's only one way to make up for it!"
The fake Mephistopheles, his body drenched in blood from his own Noble Phantasm, performed the bizarre act of digging his finger into his own skull. He then twisted his neck about 90 degrees and snapped his fingers.
"To rip you!"
"To crush you!"
"In this mansion!"
"To joyfully dissect you!!! Kyah-kyah-kyah-kyah-kyah-hack!!!"
While maintaining that grotesque pose—finger swirling inside his own head—Mephistopheles finished his nonsense and began to charge at me alongside a swarm of other Mephistopheles clones.
Some charged with scissors like killers out of a third-rate horror movie; others crawled along the ceiling or walls like spiders with their necks snapped 180 degrees like possessed victims from The Exorcist; some even attempted kamikaze assassinations where one Mephistopheles would throw another who had a Ticktock Bomb implanted in his own torso.
"For crazy bastards, this has historically been the only cure!"
Facing the army of Mephistopheles attacking from all directions—up, down, left, right—my response was to transform my hands and head into Gatling guns to shred their bodies.
The machine guns sprouting from my arms began to grind them down like a meat processor. As they fell, they began to speak in unison like a choir, spewing bizarre, nested nonsense.
"Gueeek! Is it permissible to inquire if I may request authorization to seek permission to ask whether I might raise an inquiry regarding the possibility of questioning the approval for disclosing a doubt concerning the suitability of reviewing whether it would be appropriate to report that I have a question regarding the potential to ask if there are any objections to receiving an answer signifying recognition that it is an exemplary act to inquire if I might be permitted to check whether raising a concern is not excluded under Clause 1 of Article 3 of the Other Servant Rules, while simultaneously wishing to know if it is proper to ask if I may inform you that there is a point I wish to clarify, by asking if you could judge whether it is right to request a response, and daring to reveal that I request a reply while asking if it is okay to be informed if I, this Servant Caster 3-star Mephistopheles, am qualified to perceive if there are any abnormalities when such a request is made, and by checking if you can accurately audit whether you can concede to telling me if you can say that asking such a thing would not lead to this demon becoming a 1-star Servant, while requesting you to investigate if asking whether the request of Makiri the Mage of Kiev does not fall under the same category as that of the degenerate Zouken is important to this Servant, while daring to wonder if speaking of such things would not be included in rude behavior, and requesting if you can grant a clear answer to whether I may hope for such, while repeatedly using nested interrogative sentences to ask if you feel uncomfortable, and by judging if it is alright for you to inform this Servant's lacking information body, and if I may daringly assume I have come to know this, by deliberating if it is fair to ask whether this would disgrace the honor of a Servant, and by inquiring if it is possible to be tested on the appropriateness of the question regarding what the correct answer is to the doubt I cast, and by inquiring if it is okay to conduct a survey on whether you can decide if I may perceive such facts and whether I am permitted to be conscious of the same, MIGHT I DARE TO ASK HOW THIS MEPHISTOPHELES BECAME MAD!!!!!"
He spewed out nonsense so indescribable that even I, who had experienced all sorts of madness, was left speechless. Even as their hearts were riddled with bullets and their bodies torn to shreds, they fell and exploded while breaking into fits of gleeful laughter.
About twenty fake Mephistopheles clones were wiped out at once, but others took the opportunity to burrow through the ceiling and floor to attack.
"A-hung~?!"
"…Seriously, just how many of these did you set up?"
Since he had already seen through my primary tactics, I had no reason to hold back. I unleashed a Shinra Tensei to blow them back and began slowly 'cooking' them with the transformations of the Asura Path. If turning them all into minced meat counts as cooking, then I was a master chef.
Nevertheless, Mephistopheles' war of attrition was undeniably threatening.
I could fuel the Asura Path's transformations by absorbing the prana of the dying clones with the Preta Path, but fighting like this for eternity would take a toll on my mental state. After punch-launching a Mephistopheles who tried to exploit a gap in my defense, I leaped high into the air, smashing through the ceiling to reach the floor above.