The reason Ren Kuroda could see through other people's True Names wasn't because he possessed some special skill—
It was because he'd seen this story before.
Naturally, Medea wasn't satisfied with that explanation at all. Still, after weighing the vast gap in strength between them, she chose to swallow her displeasure.
There was no helping it—reality was cruel.
After seeing Ren's parameters, Medea simply couldn't muster any desire to fight him head-on.
With her reinforcement magecraft, Kuzuki Sōichirō could rival an average Servant in combat. Even so, Medea had no confidence that the two of them together could defeat Ren.
"Fine. If you don't want to reveal your trump cards, I won't force you," Medea said coolly. "But as a condition of our cooperation, if any new Servants appear in the future, you must tell me their True Names."
To be honest, no one would've believed Ren's excuse anyway. But Medea's request wasn't unreasonable, so he nodded in agreement.
"Our chances in this Holy Grail War are still quite high," Medea continued. "As long as we win the initial faction conflict, we'll have the advantage in the internal struggle within the Blue faction. After all, we have two Servants."
Ren had been listening casually—until she mentioned factions.
"The Holy Grail War isn't supposed to be seven modern magi summoning seven Servants of different Classes, all fighting it out until the last one standing claims the Grail, right?" Ren frowned. "So what's this 'Blue faction' nonsense? Why doesn't this match the rules I know?!"
Ren knew that the Type-Moon world had seen multiple Holy Grail Wars, and that the rules sometimes changed.
But considering the Medea–Kuzuki pairing, if his memory served him right, this timeline should've been the Fifth Holy Grail War.
And as far as he knew, the Fifth wasn't supposed to be this flashy—just a chaotic free-for-all among seven Servants.
"I don't know the specifics either," Medea replied, shaking her head. "But according to the rules granted to me by the Grail, this Holy Grail War is divided into two factions.
"Red and Blue. Each faction has seven Servants of different Classes, along with their Masters.
"Our objective is to win the faction war first, then compete for the final ownership of the Grail.
"And because there are so many participants this time, there will be two winning Master–Servant pairs."
Ren was completely dumbfounded.
These rules were nothing like the Fifth Holy Grail War he knew.
And with the rules changed, he couldn't even be sure whether the Servants summoned this time were the same ones he remembered.
Even if the original lineup remained unchanged, who were the seven Servants of the other faction?
He had no clue.
"So we're the Blue faction's Caster and Assassin," Ren said slowly. "Do you know any of the others on our side? Or have you encountered anyone from the Red faction?"
Servants were already abnormal beings to begin with. And with absurd monsters like Gilgamesh or Karna potentially in the mix, Ren genuinely felt uneasy now that the plot had derailed.
"Before I killed my first Master," Medea said calmly, "I did encounter a Lancer.
"We were supposedly both part of the Blue faction, but he seemed quite displeased with me killing my Master—and even attacked me because of it."
Hearing her description, Ren immediately formed a rough idea of who that Lancer was.
Irish hero. Son of light.
The Hound of Culann—Cú Chulainn.
That Cú Chulainn would attack Medea despite being in the same faction didn't surprise Ren in the slightest.
In his legends, Cú Chulainn had once killed a guard dog by accident—and then willingly served as its replacement for a month out of sheer responsibility.
Loyalty meant everything to him.
And Medea?
Known as the Witch of Betrayal, who killed her Master almost the moment she was summoned.
From Cú Chulainn's perspective, that kind of behavior was utterly intolerable.
One was called a mad hound, the other a betraying witch—their compatibility was practically nonexistent.
Moreover, if Cú Chulainn truly belonged to the Blue faction—and Ren himself had replaced Sasaki Kojirō—
Then maybe the so-called Blue faction consisted entirely of participants from the Fifth Holy Grail War.
If that were the case, their lineup was terrifying.
Saber Artoria and the walking cheat code Emiya Shirō aside—
Heracles. Cú Chulainn.
Both were demigods.
Their combat power spoke for itself.
Of course, all of this was merely Ren's speculation.
Not all Servants had been summoned yet, so the Holy Grail War hadn't officially begun.
That entire day, Ren stayed at Ryūdō Temple, familiarizing himself with his abilities as a Servant.
Ryūdō Temple was one of Fuyuki City's spiritual nexus points. Combined with Medea's Caster-class skill Territory Creation, it had been fortified into an impregnable stronghold.
That said, such defenses were only effective against ordinary humans.
For Servants, infiltrating Ryūdō Temple wasn't particularly difficult.
While Medea was inside crafting magical tools, she suddenly sensed something and stood up from her chair, glancing toward Ren—who was sprawled on the couch binge-watching shows.
"My defensive bounded fields were triggered," she said. "Judging from the aura, it's not an ordinary opponent.
"Looks like some hunting dog has come sniffing around. Your combat abilities are… questionable. Stay here—I'll deal with him."
After leaving those words behind, Ren's body scattered into countless particles and vanished from the spot.
In truth, Medea didn't need to warn him.
Cú Chulainn had no intention of hiding at all.
The moment he entered Ryūdō Temple, he began releasing his mana freely and aggressively.
Sneaking around and ambushing wasn't his style.
He preferred open, unmistakable provocation.
Only Casters possessed Territory Creation among the seven Classes, and Cú Chulainn knew exactly whose territory he was stepping into.
But with his extraordinary skill and fearless spirit, he feared no battlefield.
A frail Caster?
Lancer didn't even put her in his eyes.
To draw the hidden Caster out, Cú Chulainn immediately went into full demolition mode.
To magi, the defensive formations here were lethally dangerous.
To the Hound of Culann, they were laughable.
As he smashed through barriers and taunted his unseen opponent, the instincts of a seasoned warrior suddenly screamed at him—
A sharp, needle-like sense of danger stabbed into his back.
Most people would've tried to dodge.
But the man Gilgamesh had once called a mad dog possessed a different kind of feral instinct.
The instant he sensed danger, Cú Chulainn didn't evade.
He reversed his grip on the crimson spear in his hand and, without the slightest hesitation, spun around and thrust—
A perfect counterstrike.
The red spear—Gáe Bolg—shot out like lightning, tearing through the air itself.
Cú Chulainn didn't know what had triggered his danger sense.
But he was confident of one thing—
If the attacker refused to retreat, mutual injury was possible.
But far more likely—
The other guy would be hurt much worse.
After all, the spear in his hand wasn't something you casually blocked.
Even without releasing its True Name, Gáe Bolg was a legendary cursed spear.
Not something any random Servant could take head-on.
Yet the moment he thrust the spear, the sense of danger didn't fade—
It intensified.
Instead of fear, a manic grin spread across Cú Chulainn's face.
"Hahaha! You've got guts! Not many people would dare face my cursed spear without dodging.
"But are you really sure you're going to trade injuries with me?
"Or are you just setting yourself up to get hurt worse?"
As a long blade slashed toward his shoulder from the darkness, Cú Chulainn smiled confidently.
As the Light of Ireland and the Hound of Culann, his martial skill was exceptional. The instant he thrust his spear, he shifted his body—
Minimizing his own damage while maximizing his opponent's.
Between a spear and a sword, the spear had a clear advantage.
With a slight adjustment, Cú Chulainn achieved the perfect posture—
Minimal injury to himself.
Maximum damage to the enemy.
The blade would at most nick his shoulder.
But his spear—
Was aimed straight for the heart.
—KRRSH!
The sound of leather armor being torn apart rang out as the blade ripped through his pauldron. Blood slowly seeped from Cú Chulainn's shoulder.
He didn't care.
What he cared about—
Was whether the other guy had been hurt worse.
As the dust kicked up by the spear's thrust slowly settled, the figure before him became clear—
And Cú Chulainn's expression twisted as if he'd seen a ghost.
"You're right," Ren Kuroda said calmly. "I never intended for us to trade injuries.
"Because when you choose to clash head-on with me—
The only one who gets hurt…
…is you."
As an Assassin, Ren possessed more than just Presence Concealment.
Stealth was a core part of the Class.
Cú Chulainn's instincts hadn't been wrong—his spear had been aimed at Ren's vital point.
It just hadn't achieved the result he expected.