A massive crimson claw of flesh shot out from the doorway and clamped down on Hiru in an instant. He immediately realized it was Muzan making his move. Without sparing a thought for the cost, he unleashed his Blood Demon Art at the flesh claw.
The crystal formed far too slowly compared to the rampant growth of the flesh. In just a blink, Hiru was completely swallowed within it.
"Oh dear…"
Doma watched as Hiru was seized and dragged toward the door, lifting his fan to cover his expression.
"Looks like I'm about to lose a friend—eh?"
Before the look of regret could fully settle on Doma's face, his attention was stolen by a blade light that illuminated half the night sky.
It was a crimson slash, wreathed in flames. The instant it appeared, there was no color in this world that could rival it.
The blade light cut straight toward the flesh claw. The moment it made contact, the claw was sliced apart as if it were butter meeting a hot knife, offering no resistance whatsoever. Doma even caught sight of the charred flesh along the severed cross-section.
The mutilated claw immediately recoiled back into the paper sliding door, which vanished without a trace along with it.
Doma's gaze shifted to the white-haired swordsman wearing a fox mask who had appeared out of nowhere in the center of the battlefield. After delivering that single slash, the swordsman made no further movements, standing silently with his sword in one hand.
[Hmm… looks like a rather troublesome swordsman… Would Freezing Cloud even work?]
Doma lowered his eyes as a faint chill spread from beneath his feet.
[Well, I suppose I'll give it a try. I can't exactly do nothing, after all…]
At the same time, Akaza felt his entire body trembling. After so many years, he was once again experiencing that same sense of helplessness he had felt when facing Kokushibo…
It was exactly the same as during that life-and-death blood battle back then. The opponent was right in front of him, yet he couldn't lock onto him at all—no, this man was far stronger than Kokushibo.
At least with Kokushibo, Akaza could sense an abnormal presence where he stood. But this man… if Akaza hadn't seen him with his own eyes, he wouldn't even exist within his perception.
[Such perfectly integrated energy… Is this the ultimate realm of martial arts?]
Akaza realized that he couldn't even summon the desire to challenge this man. It was different from the overwhelming pressure he felt when facing Muzan-sama.
This was a kind of strength so distant, so unattainable, that even the thought of surpassing it could not take shape.
[No… how can I think that? Muzan-sama is supposed to be the strongest… But is he really the strongest?]
The silence did not last long.
The swordsman turned his wrist, and his blade swept toward the severed mass of flesh. As the sword came down, in addition to the sound of flesh being cut apart, there was also the crisp sound of crystal shattering.
Once the outer flesh was stripped away, a vivid crimson crystal was revealed inside. The white-haired swordsman paused briefly, choosing not to continue destroying the crystal.
Instead, he turned his gaze toward Akaza.
In that instant, Akaza's senses were assaulted by an overwhelming pain, clearly conveying the message of death. Yet the muscle memory forged through countless years of battle made him instinctively shift his body.
In the very next moment, his pupils reflected the figure of the white-haired swordsman in perfect clarity.
There was no dazzling technique.
Akaza only felt his left arm grow strangely light, followed immediately by an intense burning sensation erupting from his shoulder. The scorching pain, as though it would spread from the wound and burn him to ash, far surpassed the earlier strike that had merely grazed his side.
What humiliated Akaza most, however, was not his inability to react in time—but the faintly puzzled nasal sound the swordsman made after delivering that slash.
[I can't see it… I can't see the movement at all… Is this what lies at the end of pursuing martial arts?]
A slight prickling sensation returned at his neck, and Akaza knew all too well that he no longer had the ability to change his fate.
All he could do was wait for death to arrive.
[Still… to witness such a supreme realm before dying… I don't regret—huh?]
The sensation at his neck vanished.
At some point, the swordsman had altered his sword path, cleaving instead into empty space behind him.
The instant the blade light erupted, an exquisitely crafted paper sliding door appeared where nothing should have existed, as though it had been waiting there specifically to receive the slash.
After briefly displaying its beauty, it burst into burning fragments and scattered away.
Akaza was just about to retreat when the ground beneath his feet vanished.
Vines of solid ice instantly coiled around his ankles, dragging him away at high speed. At the same time, lotus blossoms formed along the vines, firing one after another toward the white-haired swordsman.
With a simple turn of his wrist, the crimson flames trailing from the blade shattered every ice lotus in its path.
Entangled by the vines, Akaza did not struggle. He only strained to lift his head, staring at the swordsman.
The swordsman did not look in his direction.
Instead, he repeatedly slashed toward the crimson crystal. Every blade of light illuminated the night sky and struck the paper doors that appeared without fail.
The fragments fluttered through the air like butterflies that had flown too close to flame, dispersing with a bleak yet beautiful grace.
All of this happened and ended in a fleeting moment.
When Akaza saw the swordsman turn his gaze back toward him, his heart clenched. He grabbed chunks of nearby rubble and hurled them one after another, but none of it slowed the swordsman in the slightest.
Only when Akaza tore free a half-destroyed wall did the blade light veer slightly, as if deliberately avoiding something.
With a deft flick of his sword, the swordsman propped the remaining wall neatly to one side.
Doma noticed this immediately and manipulated his ice vines to snatch up the wall, sending it flying toward the white-haired swordsman once more.
As expected, the swordsman halted again—but this time, he showed no mercy.
He cleaved the wall apart, seized the object embedded within it, and charged forward once more.
That brief instant was enough for Akaza to see what the swordsman was holding.
[That's… a picture frame? But why…?]
There was no time to think further.
Doma dragged Akaza through the door, and at the same time, a blade light burst through, slashing toward them both.
Just as it was about to strike, the sharp, resonant twang unique to a biwa rang out. Their figures vanished instantly.
The blade light continued onward, carving a slash over ten meters long before finally dispersing.
"Oh my~ what an incredible person~" Doma gently waved his folding fan and looked up. "Thank you very much, Nakime~"
"What kind of monster was that…"
Akaza stared at the burn mark on his left shoulder, which continued to erode his body, his expression dark.
"If the Demon Slayer Corps has something like that, why would they let him live?"
"Mmm~ probably because they can kill him anytime, so leaving him alive as bait isn't a problem~"
Doma laughed.
"Still, that was really dangerous! I was just a tiny bit away from dying~"
Though he loathed Doma, Akaza had to admit he agreed this time.
Clang—
The scenery shifted once more.
When they raised their heads again, Muzan's grim face loomed before them.
"What exactly were the two of you doing? Especially you, Doma…"
Muzan looked down at the two kneeling figures. A clear wound on his right hand dripped blood incessantly.
"Why were you completely helpless against that brat? You're making me question whether you're even worthy of the title of Upper Moon."
"I'm terribly sorry~ but I really was completely countered…"
Doma lowered his head.
"Still, I had quite a pleasant chat with Akiwa~ Even though he 'ate' a lot of my memories, that transparent personality of his… If he were still human, I'd really want to try eating him~"
The pressure around Muzan dropped even further.
"Are you deliberately provoking me?"
Doma allowed Muzan to carve wound after wound into his body, his tone as light as ever.
"Of course not~ My body and soul have always belonged to you, Muzan-sama~ If you're still angry, how about digging out my eyes and playing with them? Beautiful things are great for soothing one's mood~"
Muzan stared at the bloodied Doma, veins bulging at his temples.
What infuriated him most was that there was not the slightest hint of hypocrisy in Doma's response.
In other words, every word he said was—completely sincere.
[If he weren't so gifted and useful, I'd kill him on the spot.]
Muzan closed his eyes briefly, then turned to Akaza, who had lost an arm.
"Akaza, you also disappoint me. You've been in charge of gathering intelligence—why did you fail to uncover information about that man?"
"Yes. My deepest apologies."
Akaza lowered his head in shame, though the image of the swordsman continued to surface in his mind.
[How would I need to train to reach that level? And why, among all Bright Red Nichirin Swords, could that white-haired swordsman push his blade so far?]
Muzan looked at Akaza, his anger easing slightly.
"Akaza, tell me your assessment of this battle."
"Yes." Akaza straightened. "That swordsman has already reached the realm of complete mastery. He emits no aura at all—if I hadn't seen him with my own eyes, I wouldn't have sensed him in the slightest."
"His swordsmanship is equally unfathomable, surpassing even that traitor Kokushibo. But the most troublesome part is the Bright Red Nichirin Sword he wields. Once struck, there is no solution."
Akaza hesitated slightly before continuing.
"However, there is one thing that bothers me. That swordsman clearly had the ability to kill me, yet he prioritized protecting that demon."
"Later in the fight, he also placed great importance on the painting on the ruined wall…"
"Go on."
"Although the exchange lasted only a moment, I'm certain that compared to slaying demons, that white-haired swordsman was more focused on protecting that demon."
"I don't believe that, for a Demon Slayer Corps member, a single painting would be more important than killing an Upper Moon."
"Ah~ I think I know a bit about that~" Doma tilted his head, blood still dripping from his wounds.
"That was a painting by Yomi-sensei. I've collected quite a few of his works, since I can always feel the emotions the painter wanted to convey~"
"He probably avoided it because Akiwa really likes Yomi-sensei's paintings, and that swordsman cares deeply about Akiwa, don't you think~?"
"Akiwa?" Akaza looked puzzled. "That sounds like a woman's name."
"Mmm~ I don't know his real name either, but when he dressed as a woman to meet me, that's the name he told me~" Doma smiled. "He was really cute~"
"Yomi…"
After a brief silence, Muzan's lips slowly curled into a cruel smile.
"Heh… what an unexpected discovery, Doma."
"Yes, I'm here~"
"From today onward, you will be responsible for purchasing those paintings from various places. I'll have Gyokko cooperate with you. Bring the paintings to me as quickly as possible."
"Yes~ I'll handle it properly~"
Doma's wounds finally began to heal.
"Come to think of it, many of my previous art pieces were chosen with Gyokko's help too~ He's always had excellent taste~"
"As for you, Akaza…" Muzan's plum-red eyes swept over him, his expression darkening once more. "You will investigate that swordsman. The more information, the better…"
"Hmph. After Tsugikuni Yoriichi's death, Ubuyashiki actually found another Sun Breathing swordsman… What an irritating bunch of insects."
"Yes. I will devote myself fully, even at the cost of my life."
Two tubular whips extended from Muzan's back and pierced straight into the foreheads of the two demons.
Large quantities of blood surged through the whips into their bodies.
"This time, I'll let it slide. Don't disappoint me again."
"Yes~"
"Understood."
After instructing Nakime and the others to help them recover and send them away, Muzan sought out a room within the Infinity Castle for himself.
He picked up a medical text, but his eyes did not focus on the words.
Instead, he carefully sifted through memories from Kokushibo—recalling a conversation they had once shared while Muzan was hiding and recovering from the grievous wounds inflicted by Tsugikuni Yoriichi.
[How did you find me?]
[You need not worry. I have no intention of opposing you. I am merely fulfilling my duty as a subordinate, guarding your safety.]
[Hmph… even after I slaughtered your entire family?]
[…It was my own decision to abandon my bonds as a human. It has nothing to do with you.]
[Didn't you still leave that boy alive in the end?]
[Because I once promised him that I would protect him. One who breaks faith has no place in this world… That was simply the final thing I did as Tsugikuni Michikatsu.]
[Raised by the clan from childhood—how long could he survive once that protection was gone? Kokushibo, you made a foolish move.]
[My younger brother loved painting from a very young age and had considerable talent. However, the family disliked the fame it brought, so he never became well-known.]
[Perhaps free from the family's restraints, he will thrive all the more.]
[Oh? Does he have a name?]
[His pen name is Yomi.]
"The boundary between day and night…"
Muzan let out a low snort.
"My oversight. Kokushibo's troubles will be resolved soon enough…"
"Tsugikuni Hiru, next time, I won't give you a chance to live."
…
Standing amid the ruins, Yoriichi gazed at the paper door that had once again turned to dust.
After a brief silence, he frowned slightly.
"…Did he escape?"
At that moment, the sound of crystal shattering rang out.
Yoriichi hurried over, just in time to see Hiru step out from the broken crimson crystal, his expression fierce.
"Damn that spatial Blood Demon Art… damn Muzan…"
Yoriichi paused for a moment, then handed over the painting he was holding.
"Hm? Are you taking everything the Kakushi recovered?"
Hiru accepted it instinctively, then quickly realized something was off. He looked up at Yoriichi.
"Wait—where's Muzan? The Muzan I went through all that trouble to lure out?"