Shirou Emiya's own magical energy hadn't increased by even the slightest amount—but what left Rin Tohsaka genuinely stunned was that the mana radiating from Saber had undeniably grown stronger.
This was seriously insane. What Ren Kuroda had just done truly left Rin at a loss for words.
If you said Ren hadn't done anything at all, that clearly wasn't true—Saber's magical aura had visibly intensified.But if you said he had done something, then why hadn't Shirou Emiya, Saber's Master, changed in the slightest?
Unless Assassin—Ren Kuroda—knew of some special, hidden mechanic of the Holy Grail War that they didn't, how else could he possibly increase a Servant's power through another Master?
Rin could only come to that conclusion. After all, the Holy Grail War only occurred once every sixty years, and its rules were notoriously convoluted. Over the generations, plenty of mages had discovered loopholes and obscure exploits within its system.
And if Assassin really did come from the future, then knowing secret mechanics they were unaware of… didn't seem strange at all.
"Assassin," Rin said casually as she sidled up beside him, lowering her voice, "we all know each other pretty well by now, and we've gotten along decently so far. About magical energy replenishment in the Holy Grail War—are there any special mechanisms involved? Would it be… inconvenient for you to share a little?"
It couldn't be helped. Using her authority as a Master, Rin had seen Saber's parameters jump in a short span of time—from the infamous 'Glutton King' to a full-fledged 'All-A King'.Her heart had been thoroughly shaken.
She even started imagining things—Assassin and Caster were both absurdly powerful. What if their strength came from abusing this kind of behind-the-scenes trick?
Watching Rin creep over and whisper conspiratorially, Ren Kuroda couldn't help but smile wryly.
Clearly, none of them knew about the existence of Avalon, the scabbard embedded within Shirou Emiya's body. They'd completely mistaken his earlier actions as him exploiting some hidden Grail War system.
"Even if I told you that what I just did was a perfectly normal mana supply process," Ren said calmly, "you'd probably assume I was hiding something anyway. But the truth really is that simple."
Rin, of course, didn't believe him for even a second. But she didn't find it strange either.Even though their relationship was relatively amicable for now, once the faction battles ended, they were still destined to fight each other.
If she were in his position, she wouldn't reveal something that important either.
So Rin took a step back—and then changed tactics.
"If it's classified information, then fine," she said, crossing her arms. "In that case, Assassin, why don't you help me replenish mana too?"
"You're not really that stingy, are you? Archer is fighting Caster head-on right now just to stall that sea monster. If only Saber gets stronger, isn't that a bit unfair?"
Seeing how Ren had merely patted Shirou's shoulder and instantly turned Saber into a monster, Rin couldn't help but feel tempted.
So this was mana replenishment? It didn't seem nearly as indecent as she'd imagined.
Archer was weak—painfully weak. And since Assassin had such overwhelming mana reserves, why not let him replenish hers too? Maybe it could finally strip Archer of that humiliating third-rate Servant label.
"Cough—cough—Rin," Ren choked, nearly sputtering. "Are you… actually serious about letting me replenish your mana? If Archer found out about this…"
He genuinely hadn't expected this. After being dragged into the Nasuverse by sheer coincidence, the amount of benefits he was running into was ridiculous.
The girls here were far too proactive.First Saber, who had been prepared to make a sacrifice earlier—and now Rin, outright requesting mana replenishment herself.
If every world was like this, even someone with golden kidneys wouldn't survive.
"So what if Archer finds out?" Rin shot back confidently. "I'm the Master. And I'm doing this for his sake—to make him stronger."
Ren felt like he'd learned something new that day.So… wearing a green hat made you stronger now?
Still, to avoid being subjected later to a coordinated beatdown by both Rin and Heroic Spirit Emiya, Ren finally explained her misunderstanding of "mana replenishment."
He clarified that Shirou's situation was special—and that if Rin wanted to replenish mana with him, the standard method would still be unavoidable.
Once she understood the truth, Rin's face instantly flushed crimson.
She'd just volunteered to let Assassin replenish her mana…That was shameless beyond belief!
With Avalon's magical energy fully restored, Saber once again returned to her peak—the All-A King—and her confidence surged.
"Caster, enhanced by Command Spells, is far stronger than before," Saber said solemnly. "I can't be sure whether my Noble Phantasm will completely destroy him—but it's our only option now."
"To unleash its full power, I'll need time to gather enough mana."
Feeling the torrent of magical energy coursing through her body, Saber was visibly exhilarated.And though she wasn't sure why, she faintly sensed a strange connection—to Ren Kuroda.
Even though Ren's mana had restored her to her peak, she inexplicably felt… linked to him.
But there was no time to dwell on it.
Saber raised the Sword of Promised Victory high above her head. Golden light began to converge along the blade.
What even Ren himself hadn't realized was that a genuine connection had indeed formed between them.
Although Saber's Master was nominally Shirou Emiya, the true anchor had always been Avalon, the scabbard within his body.
In the past, Avalon's mana had been accumulated over years inside Shirou—but due to his mediocre magical talent, most of it had already been consumed during Saber's summoning.
What little remained wasn't nearly enough for sustained combat, severely weakening Saber.
But now that Ren had replenished Avalon with his own mana, Saber had returned to her peak—and that mana now belonged to Ren.
In effect, through Avalon as a medium, Ren Kuroda had become half of Saber's Master.
The other half was Shirou Emiya, who had summoned her.
The strange sensation Saber felt was the result of this subtle, unprecedented Master–Servant bond.
Normally, a Heroic Spirit could never become another Servant's Master—unless they were someone like Medea, wielding a special Noble Phantasm and profound magecraft knowledge.
But Ren was different.
Unlike other Servants, he possessed a physical body.Calling him a Heroic Spirit was correct—but calling him a mage wasn't wrong either.
Golden light gathered like fireflies in the night, converging atop the bridge's elevated platform—toward a girl holding a knight's sword aloft.
Meanwhile, Ren Kuroda, Heroic Spirit Emiya, and Archer relentlessly assaulted the sea monster, buying Saber the time she needed.
If even Excalibur failed to finish Caster, then Ren would have no choice but to reveal his full strength early.
Though "Wind, Forest, Fire, Mountain" was more suited to personal combat and lacked raw destructive power, once he removed his mana restraints and activated Half-Demon Transformation, sheer magical output alone would turn even ordinary slashes into devastating attacks.
The sea monster roared in fury, its patience finally exhausted by the relentless pests before it.
Even Caster had to admit he'd underestimated them.
With the legendary sea beast summoned and amplified by Command Spells, he'd believed the rest of the Holy Grail War would be a simple steamroll.
Yet Ren and the others had exceeded his expectations.
Rider and Assassin were one thing—but that Archer he'd completely dismissed?Every arrow he fired was a Noble Phantasm.
Wasn't that a bit excessive?!
Facing the massive, regenerating sea monster, Heroic Spirit Emiya felt utterly helpless.
The deeper the Grail War went, the more he realized Rin had been right—he really couldn't beat anyone.
In a one-on-one fight, Emiya was confident he could instantly kill Caster.But fused with the sea monster, Caster was completely untouchable.
His strongest projected Noble Phantasm—Nine Lives: Shooting the Hundred Heads, modeled after Heracles—had already been used.
At best, it had destroyed half of the monster's body.
A projection could never fully match a true Noble Phantasm—and with Command Spell enhancement, Caster's durability was far greater than before.
Still, the unluckiest one wasn't Emiya.
That honor belonged to the King of Conquerors.
Emiya's Noble Phantasms were disposable projections—blowing them up only cost mana.
But when Emiya destroyed half the monster, the King of Conquerors saw an opening and decisively detonated his own Noble Phantasm—Gordius Wheel.
Caster was still very much alive.
The result was obvious.
By the time Ren finished replenishing Avalon and arrived, saying all they needed to do was stall for Saber, the King of Conquerors could only smile bitterly.
"You could've said that earlier," he muttered. "I just blew up my ride."
That divine bull chariot had been his last remaining symbol of kingship in this war.
Now gone—without results.
Left with only his sword, he could barely scratch the sea monster.
Despite his immense charisma and leadership, his personal combat strength was… painfully average.
Compared to Ren's casual, devastating slashes, the King of Conquerors' sword strikes were little more than acupuncture needles.
"As the King of Conquerors," he laughed awkwardly, "my personal strength is actually quite ordinary. I became king because of my comrades—and my ability to command them."
Earlier, he'd tried to recruit Ren.
Now, seeing the negligible damage he dealt, even he felt too embarrassed to push the matter further.