In a side courtyard of the Butterfly Mansion, Tengen Uzui had already gathered Tanjiro, Zenitsu, and Inosuke like a group of chicks and taken them off to the dressing room, preparing for his so-called "flamboyant makeover."
Rin had no interest in joining the spectacle. He knew perfectly well how disastrous those three would look once they were dressed as women.
With the bag Shinobu Kocho had prepared slung over his shoulder, Rin walked leisurely along the corridor of the inner courtyard, one hand tucked into his pocket, heading toward the main gate of the Butterfly Mansion.
Just as he passed beneath the cherry blossom tree in the front yard, he suddenly stopped.
On the wide stone-paved clearing, four figures had appeared at some unknown moment.
The Flame Hashira, Kyojuro Rengoku. The Wind Hashira, Sanemi Shinazugawa. The Serpent Hashira, Obanai Iguro. And at the very edge, standing as rigid as ever, the Water Hashira, Giyu Tomioka.
These four pillars of the Demon Slayer Corps were not wearing their haori, only their standard black uniforms, their Nichirin Blades resting at their waists.
As soon as Rin stepped out, the low conversation among them ceased, and all their gazes converged on him at once.
"What's this? I haven't even stepped out yet, and you've already lined up to see me off?"
Rin looked at their formation, a faint smile tugging at the corner of his lips.
"Cut the sarcasm."
Sanemi Shinazugawa stepped forward half a pace, his expression as fierce as ever. But on closer look, the bloodshot hostility from their first meeting was gone, replaced by a restrained seriousness.
"Kyojuro told us everything about the Mugen Train. Even if you used that strange illusion to deceive Kibutsuji Muzan into thinking Upper Rank Three retreated because of sunrise… we all know you were fully capable of twisting his head off right there."
Sanemi clenched his teeth, as if forcing himself to swallow his pride.
"I didn't come here today to pick a fight with you. I just want to know one thing… how strong is Upper Rank Three?"
Obanai Iguro, perched on a tree branch, spoke in a cold voice, "For a hundred years, the Upper Rank positions have never changed, while the number of Hashira who have died at their hands is beyond counting. We only know they are strong, but because no one survives, our intelligence is always incomplete. Since you fought him head-on, I want to hear your assessment."
Not just him—even Giyu Tomioka stepped forward slightly, silently focusing his attention.
So they were here to probe the truth.
Rin looked at this group of swordsmen who, in the original story, would throw themselves into battle against demons without hesitation, even at the cost of their lives. The casual expression on his face faded.
He walked over to a large boulder at the edge of the courtyard, braced one hand against it, and swept his gaze across them.
"Since you're asking so sincerely, I'll be blunt. Consider it a reality check before you face an Upper Rank."
His voice was calm, yet it carried clearly across the quiet courtyard.
"First, the conclusion. With your current strength, if you face Upper Rank Three—or either of the two ranked above him—in a one-on-one fight, your chances of survival are zero."
The words hit like a heavy hammer, slamming into everyone's chest.
A vein bulged on Sanemi's forehead. Just as he was about to snap back, Kyojuro Rengoku raised a hand to stop him.
"Umu! Rin-dono speaks the truth!"
Kyojuro Rengoku crossed his arms, openly acknowledging the gap in strength.
"At the Mugen Train, when the demon named Akaza appeared, I felt his battle spirit, and my body instinctively warned me of danger. If Lord Rin hadn't intervened, even if I had risked my life, I could at best have held him off until sunrise. I would not have been able to behead him."
"Battle spirit—that's the core of the issue."
Rin snapped his fingers, picking up from Rengoku's words.
"As Hashira, after years of life-and-death combat, every breath you take and every strike you make is filled with killing intent and battle spirit. But in front of Akaza, that very battle spirit is a death sentence."
"What do you mean?" Obanai Iguro frowned deeply.
"His Blood Demon Art is called Destructive Death: Compass Needle. It functions like a radar-based sensory domain." Rin tapped his temple. "Within that domain, he can precisely detect the trajectory, speed, and even blind spots of an attack based on the battle spirit emitted by his opponent. The stronger your killing intent and the more intense your battle spirit, the clearer your movements become to him."
"It's like trying to assassinate a master archer in the dark while holding a torch. No matter how refined your swordsmanship is, he can use the Compass Needle to predict your moves and execute the most precise dodge and counterattack the moment you act."
As soon as this explanation was given, the entire courtyard fell into a heavy silence.
Sanemi's knuckles turned white from gripping his sword hilt too tightly.
As the Wind Hashira, his fighting style was known for its ferocity and aggression.
If Rin's words were true, then his proud technique would be nothing more than a series of predictable, wide-open attacks in front of Akaza.
"And that's not all. The regenerative ability of the Upper Ranks is on a completely different level from the demons you usually deal with."
Rin raised a finger, continuing his explanation.
"If you sever one of his arms, he can regenerate it in half a second. But you? As humans, once your organs are damaged or your bones are broken, your combat ability drops sharply. In a battle of attrition, stamina is always humanity's greatest weakness."
"Then is there really no way to defeat him?"
Even the usually calm eyes of Giyu Tomioka showed a ripple of urgency.
"There is."
Rin stepped down from the rock and clapped his hands once.
"The first method is to overwhelm him with absolute speed and power, exceeding the limits of his Compass Needle. If your attack is faster than his perception—so fast that his mind can register it but his body cannot react—then he has no choice but to take the hit."
The corners of everyone's mouths twitched slightly.
That method might as well have been no method at all.
In the entire world, probably only the monster standing before them—someone who could manifest Susanoo and treat an Upper Rank like a punching bag with his bare hands—could achieve that.
"The second method is to transcend your current limits and enter a state known as the 'Transparent World.'"
Rin glanced at the group. "Completely suppress all killing intent, battle spirit, and even emotional fluctuations. Let your heartbeat and blood flow slow to the bare minimum. In your opponent's perception, you'll be no different from a lifeless stone. Only by entering a state devoid of battle spirit can his Compass Needle be rendered useless."
"A state without battle spirit…" Kyojuro Rengoku murmured, as if trying to grasp the possibility of such a realm.
"Don't think it's that simple."
Rin cut off his thoughts without hesitation.
"The prerequisite for entering the Transparent World is awakening the Demon Slayer Mark. That mark only manifests in an extreme near-death state—when your body temperature exceeds thirty-nine degrees and your heart rate surpasses two hundred beats per minute. Before that, if you're unlucky enough to encounter one of the top three Upper Ranks while on a mission…"
Rin paused, a cold smile forming at the corner of his lips.
"Don't hesitate. Send a signal immediately and call for backup. Holding out until I arrive is the only way you'll survive."
These words laid bare the overwhelming pressure of the Upper Ranks and completely shattered the pride of the usually confident Hashira.
Yet it was precisely this brutal truth that stirred the blood in their veins.
"Transparent World… Demon Slayer Mark…" Sanemi Shinazugawa loosened his grip on his sword hilt and took a deep breath. The ferocity on his face faded slightly, replaced by a determined resolve. "Thanks for the information. I won't die for nothing. Before I tear that bastard Muzan apart, I'm holding on to this life."
"Well then, I wish you success on your trip to the Yoshiwara Entertainment District." Obanai Iguro leaped down from the tree. "That place is a den of hidden dangers. Since the Sound Hashira was assigned there, it won't be simple. If you encounter an Upper Rank, don't let it escape."
"Don't worry. As long as it dares to show itself, there will be only one outcome—turning to ash." Rin waved a hand casually, signaling that they didn't need to worry.
In this tense atmosphere, heavy with killing intent—
"Sorry to keep you waiting! Now, allow me to present the most flamboyant Yoshiwara oiran personally crafted by this god!"
Tengen Uzui's overly flashy voice rang out from around the corner of the corridor.
A series of slightly heavy footsteps followed.
The four Hashira and Rin all turned their heads at the same time, looking toward the source of the sound.
"..."
The next moment, the entire courtyard fell silent.
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12 Advance chapters:Patreon/slept01