From Master's Kasugai Crow, Asuka learned something important.
Among the Hashira-class swordsmen of the Demon Slayer Corps during the Warring States era, there had once circulated a power known as the Demon Mark.
These marks resembled the claws and fangs of demons, ferociously clinging to the surface of the human body, yet they could drastically enhance a person's strength and reaction speed.
When Asuka fought Akaza, similar patterns had appeared on his face. This had greatly concerned Master, who specially dispatched a Kasugai Crow to verify the matter.
The inheritance of the Demon Mark had grown vague over generations of near annihilation within the Demon Slayer Corps, compounded by earlier neglect.
Only one sentence had been passed down through the ages:
"As long as one awakens, more swordsmen will awaken in succession, as if in resonance."
Now, in the records of the Flame Hashira, Asuka saw a similar statement.
Demon Mark… so that feeling, like his whole body was about to burst into flames, had been this…
"So the Demon King Muzan was truly that powerful, that even the swordsman of the original Breathing Style could not…" Kyojuro Rengoku stared blankly at the Flame Hashira's book before him, lost in thought. "…Sun Breathing—so that is the name of the first Breathing Style…"
Asuka glanced at the somewhat dazed Kyojuro, his expression turning more solemn.
Just as he was about to speak, Kyojuro suddenly laughed.
"Ha ha! How wonderful! The origin of Flame Breathing—Sun Breathing! How powerful!"
Rengoku's eyes burned brightly as he crossed his arms. "Asuka, I suddenly have an idea! If we gather the Five Major Breathing Styles together and search for their commonalities, perhaps we can reverse-engineer this mighty Sun Breathing!"
"Even if I cannot learn it, someone will! That would make the Demon Slayer Corps even stronger!"
"If one person cannot do it, then ten! A hundred! As long as enough swordsmen master Sun Breathing, even the Demon King would have no choice but to flee in disgrace!"
Such a sunny and straightforward thought dispelled the faint worry that had just risen in Asuka's heart.
He looked toward a corner of the room. Behind the wall there, someone had been eavesdropping, their breathing noticeably unsteady.
See that? This is the difference between you and him.
Avoidance and negativity will never change the fact of your weakness. Only by moving forward relentlessly can you do so.
Asuka withdrew his perception and refocused on the Flame Hashira's book.
"Kyojuro, what do you know about a burning blade?"
"A burning blade…" Rengoku thought carefully, then shook his head. "But now that you mention it, during your battle against the Upper Rank demon, why was your blade so intensely hot? It even prevented the Upper Rank from regenerating."
"I'm not sure. I think it may be related to the Demon Mark." Asuka pointed to the record in the Flame Hashira's book concerning Yoriichi Tsugikuni.
"The Demon Mark?"
Seeing Rengoku's puzzled gaze, Asuka combined his own experience with the contents of the book and explained everything to him.
On the other end of time.
Three months earlier, Tokyo, the Hirota residence.
With a cold expression, Muzan withdrew his finger from Akaza's head, his mood at its absolute worst.
There was no mistake…
That mark. That burning Crimson Blade.
Had that damned Yoriichi Tsugikuni reincarnated? Or had some other inheritor of Sun Breathing slipped through his grasp?
He recalled the boy wearing Yoriichi's earrings and felt a surge of irritation.
"In the end, it's because you useless trash failed to kill Tanjiro Kamado early on! That's why things have developed into this!"
He roared, and even the glass shattered from the force of his voice.
Akaza said nothing, kneeling silently on the ground, awaiting Muzan's judgment.
Aside from his fear of Lord Muzan, he truly did not feel like speaking.
Asuka's slash had torn open his neck—and torn open a corner of his memories as well.
Koyuki… Keizo…
The two names crashed repeatedly through his mind, stirring his heart into turmoil, yet he could not recall who they were.
He felt that Lord Muzan had taken part of his memories, but he did not know how to ask, and feared that once he spoke, they would be erased again.
Moreover, he knew that if Lord Muzan wished, he could read the thoughts of the Twelve Kizuki at any time.
So he could only bury those two names deep in his heart, trying his best not to think about them.
"Akaza."
After tearing several books to shreds, Muzan's fury gradually subsided, and his tone returned to its usual cold chill. "I am growing weary of hiding like this. At this rate, when will we ever find the Blue Spider Lily?"
He sat down in a broad velvet armchair, fingers interlaced, looking down at Akaza.
"I intend to conduct a hunt."
"A hunt?" Akaza did not understand and looked up at the faint smirk on Muzan's lips.
"That's right. A hunt targeting the Demon Slayer Corps." His gaze fell upon the word "Upper Rank" in Akaza's eyes as he continued, "Whether you admit it or not, you were defeated by the Demon Slayer Corps. Their morale is at its peak right now."
"However, this is also an opportunity for us…"
"I plan to take advantage of their complacency and release a few pieces of bait to draw their attention—preferably the attention of the Hashira."
"After all, having just defeated an Upper Rank demon, they must think the others are nothing special, hmm…"
Muzan counted on his fingers, then settled on two names.
"Doma. Daki."
"I will leak information about them, let the Demon Slayers investigate, and then catch them in a trap—slay the Hashira-class swordsmen who come to support! That should not be difficult for those two, as long as they do not encounter the swordsman with the Crimson Blade."
He stood and paced to Akaza's side.
"As long as both sides can take down enough Hashira, the leader of the Ubuyashiki family will certainly panic. Through the subtle traces of their personnel movements, we will find their headquarters!"
Crimson pupils burned with fury, pale fangs flashing in a savage grin.
"When the time comes, I will lead you all and march straight into the Demon Slayer Corps' nest!"
"A mere swordsman with a Demon Mark—do you think he can kill us all? This time, we will completely wipe out the Demon Slayer Corps!"
Seeing Lord Muzan so confident, Akaza did not know what expression to show.
He simply lowered his head and responded firmly, feigning equal battle spirit.
Whether the Demon Slayer Corps would truly be destroyed, he was not certain.
But he did very much want to follow Lord Muzan and storm their headquarters.
'Black-haired boy, this time I will win,' he thought.
"Very well. You may withdraw until further orders."
Muzan waved his hand dismissively. "Oh, and investigate that black-haired swordsman. He should be a user of Wind Breathing, yes? Find out where the Wind Breathing training grounds are."
He frowned impatiently.
"One after another, those old relics hide in the deep mountains and forests, ruining my plans. They would be better off all dead."
Akaza accepted the order and withdrew, his figure vanishing swiftly into the night wind, leaving behind a large, shocking pool of dark red blood upon the carpet.
After he left, Muzan sat alone in the vast, luxurious room, his crimson eyes fixed upon the locked ebony cabinet.
"What exactly is this thing…"
After thinking it over, he still felt uneasy. In the end, he opened the cabinet again and began experimenting with a flask containing Akaza's flesh and blood, mixing it with other colored reagents.
Outside the window, the lights of Tokyo burned through the night, bustling and brilliant.
Yet from this very point, the Demon King's shadow was spreading outward.
It stretched toward a distant snow-covered mountain shrine and swept toward the glittering pleasures of the Yoshiwara district.
The night was deep.