The matter of Tanjiro overcoming sunlight was ultimately left unresolved. After all, with Yoriichi and Hiru already setting such precedents, one more person capable of withstanding sunlight would not significantly change the overall situation.
However, the revelation that he had mastered the Transparent World made every Hashira instinctively tense again.
Even the Aura sense Yoriichi had previously taught them had already proven invaluable. Although none of the Hashira except Gyomei could maintain that state continuously, simply applying it during combat had already led to a qualitative leap in their fighting ability.
Under normal circumstances, everyone would have started firing off questions immediately. Those closest in age to Tanjiro—especially the twins—might even have dragged him aside, knowing how terrible he was at refusing people, and pressed him for every detail on how to master the Transparent World.
But after everything that had just happened, no one quite knew how to bring it up.
It was only when Yoriichi, during his report, revealed that he had located the Infinity Castle that the awkward tension in the room finally eased somewhat.
"So you've finally caught Muzan's trail?" someone asked.
"Yes," Yoriichi replied, lowering his head slightly. "After the incident involving the Eternal Paradise Faith, I was able to grasp certain patterns behind Spatial Blood Demon Art. Using that understanding, I managed to track down the location of the Infinity Castle."
"However, this new method is still difficult to control precisely, and the enemy reacts extremely quickly. Every time I find an opening, I fail to break through. At best, I can only sever the connection between that location and the Blood Demon Art."
"So the sword marks I saw back then really were left by my brother."
"Yes. Unfortunately, this method of searching is still rather slow." Yoriichi's gaze shifted slightly. "But now that Tanjiro has overcome sunlight, Muzan will become even more impatient. It likely won't be long before he exposes a weakness."
"I see… It seems fortune has favored us once again." A gentle smile returned to Kagaya's face. "Hiru, you once mentioned that Tanjiro can be turned back into a human, correct?"
"Yes. But the materials required for the medicine must be imported from overseas." Hiru lifted his head slightly. "If the Ubuyashiki family's connections can speed things up, the ingredients should be obtainable within a month."
"If possible, I would prefer to delay the final battle until after this child has returned to being human."
"Tanjiro was turned into a demon by Muzan, and not much time has passed since then. If Muzan were to come into contact with him, he could easily absorb him."
"But I'm different. My blood is not the same as his. On top of that, I've been consuming various medicines made from wisteria for hundreds of years. Even if devouring me allows him to overcome sunlight and wisteria afterward, the act itself will inevitably leave him in an extremely weakened state."
"And that will be the moment when—"
"Hold it right there."
Uzui suddenly felt the hairs on the back of his neck rise. He reached out and planted a hand firmly on Hiru's shoulder, cutting him off.
"Why are all your plans built around sacrificing yourself? Are you that eager to die?"
"Of course I want to live if I can," Hiru replied calmly. "But you all experienced it in the illusion, didn't you? When I was human, I was completely ordinary. I didn't have your ridiculous reaction speed or physical strength."
"After becoming a demon, I spent most of my time beside my brother, so I never focused much on physical training. I specialized almost entirely in Blood Demon Art."
He shrugged.
"If I'm being honest, I've only started seriously training my physical combat over the past few years."
"Against demons who rely mainly on Blood Demon Art, I'm quite confident. But against demons who specialize in close combat… I'm completely outmatched."
"And I refuse to believe that Muzan—after being cut to pieces, escaping, and recovering—hasn't improved himself in that regard."
"Of course," he added lightly, "no matter how much he improves, he'll never surpass my brother. Last time my brother was simply caught off guard and couldn't finish him. The next time they meet, Muzan won't escape again."
But hearing all this only made Uzui's expression grow darker.
He raised a finger and repeatedly poked Hiru in the forehead.
"Compared to Muzan, you're the one who actually wants the Demon Slayer Corps wiped out, aren't you?" he said flatly. "First you say we can't defeat Muzan. Then the very next moment you're planning to kill yourself and leave us with a Yoriichi who's lost his restraint."
"You definitely hold a grudge against the Corps. No—there's no doubt about it."
"You're the one talking nonsense!" Hiru slapped his hand away. "Uzui! Even Buddha's patience has limits! Touch me again and I'll break your bones, do you hear me?!"
"Then try it! A useless Demon King like you couldn't even reach the heel of this God of Festivals!"
The two immediately began arguing loudly, their voices rising as if they might actually start fighting.
Strangely, however, the atmosphere in the room grew lighter instead of more tense.
Even Kagaya made no attempt to stop them.
At last, Yoriichi could no longer remain silent.
After letting out a quiet sigh, he spoke in a voice filled with exhaustion.
"Hiru. That's enough."
"But he's completely wrong, isn't he?" Hiru turned toward him. "What exactly is wrong with my reasoning? If sacrificing one person could stabilize the situation, anyone would choose to sacrifice themselves first."
The room fell silent once more.
Tanjiro desperately wanted to say that this way of thinking was wrong.
But after thinking about it for a moment, he realized something.
If the future truly required someone to be sacrificed… he would absolutely hope that person would be himself—not his family, and not his friends.
Realizing this, Tanjiro lifted his head and looked at Yoriichi, whose lips were pressed tightly together.
[Sensei must feel the same way…]
[ That's why, even though he's so angry, he still can't bring himself to stop him.]
"Hiru is correct."
The gentle voice from above made everyone look up.
Kagaya sat upright on the tatami, a calm smile still resting on his face.
"If the day ever comes when sacrificing one person can stabilize the situation," he said softly, "then I sincerely hope that person would be me, rather than anyone present here."
Hiru snorted and shot Uzui a smug glance.
"See? Even the Master agrees with me."
"But there is one thing you misunderstand, Hiru," Kagaya continued, lowering his eyes slightly.
"Only a leader should face such decisions."
"Though it is merely a title, I am the head of the Demon Slayer Corps. It was also my decision to conceal the identities of the two of you."
"If consequences must be borne, then I should be the one to bear them."
"You, Hiru, do not need to make that choice."
"And when the day of the final battle arrives, if someone truly must be sacrificed…"
He paused.
"…it should never be those who can still fight."
His voice remained gentle.
"But rather someone like me—whose body is frail and of little use in battle."