"Brother, you have a way?"
Hiru was undoubtedly the most surprised person present. For hundreds of years, Yoriichi had lived with little desire or attachment. When he wasn't causing trouble, his life revolved solely around sword training and meditation.
So hearing him say he had a solution caught Hiru completely off guard.
As if noticing his reaction, Yoriichi shook his head slightly.
"It's not that I'm proficient in this. I only have a rough idea."
Hiru thought back over his long life, making sure he hadn't missed anything before speaking.
"But we haven't encountered anyone like a puppet master in the past few centuries, right? If we had, there's no way I wouldn't remember."
"That was when I was still human, so naturally you wouldn't know," Yoriichi explained. "After my wife passed away, I went through a period of despair. During that time, I was invited by Rengoku Tetsushiro to join the Demon Slayer Corps.
It was through Tetsushiro that I first learned about demons. After that, I modified my Breathing Styles and passed them on. He also invited me to join the Demon Slayer Corps.
But I was consumed by grief and had no heart to consider such things, so I refused. Even so, Tetsushiro persuaded the Corps to gift me a Nichirin Blade. I used that blade to slay demons until I became one myself, and only then did I use it to fake my death.
The swordsmith who forged my blade was rather eccentric. He insisted on seeing my swordsmanship before agreeing to forge it. After I demonstrated my techniques, he said he wanted to create a training puppet modeled after me."
Hiru nodded in understanding.
"So in other words, Swordsmith Village likely still preserves that puppet-making tradition?"
"That's my thought," Yoriichi nodded. "Swordsmiths are closely tied to swordsmen, and since the puppets were used for training, the method should have been passed down. It's the most suitable place to start."
"Hmm. I see!" Rengoku spoke up energetically. "Then I'll head back and check the clan records to see if there's any mention of that swordsmith!"
"I wouldn't get your hopes up…" Hiru sighed. "You've seen the corpse collectors from our era, right? Aside from the one family I protected, all the others lost their lineage long ago. And a training puppet modeled after you… most swordsmen would just get crushed and lose all confidence."
"Enough talk. Let's just get everything prepared," Uzui crossed his arms. "I'm the fastest, so I'll report to Oyakata-sama."
"Then I'll head to Swordsmith Village afterward~" Mitsuri clasped her hands with a bright smile. "My blade needs adjustment anyway since it's been wearing down~ Oh, speaking of which, doesn't Iguro-san's blade need tuning too?"
Obanai nodded.
"Yes. Blades like ours, the more unconventional ones, do wear down faster."
"That's perfect! Then let's go together! I was worried I might mess things up on my own, but with reliable Iguro-san, I feel totally at ease!"
"Indeed. It seems your wish will soon come true, Mitsuri!"
"Oh, come on, Kyojuro, don't tease me!"
Watching the lively discussion, Hiru finally felt some of the tension lift from his shoulders. But then he remembered something and turned to Yoriichi.
"By the way, Brother, could you take a look at Muichiro?"
"Hm? What's wrong with Muichiro?"
"You don't have a crow right now, so I couldn't contact you earlier," Hiru said, pulling Muichiro, who had been standing with Tanjiro, over. "This kid activated his Slayer Mark during his fight with an Upper Moon, but it disappeared afterward."
Yoriichi lowered his gaze to Muichiro. After a moment of silence, he asked,
"Can you activate the Slayer Mark again? Let me see."
Muichiro nodded, closed his eyes, and focused on his Breathing Styles. This immediately drew the attention of the other Hashira again, all of them watching closely.
After just two deep breaths, the Slayer Mark appeared on Muichiro's face.
Yoriichi let out a soft sound of surprise.
Muichiro looked up.
"Did I do something wrong?"
"No… Using the Transparent World, I can see that the degree to which the Slayer Mark affects your body is far less than what I've seen in others.
If most swordsmen who fail to learn how to suppress the Slayer Mark can only live to twenty-five, then you could live to thirty, or even thirty-five. This means your body has a high compatibility with the Slayer Mark. That is a good thing."
"Can that kind of constitution only be judged after activating the Slayer Mark?" Uzui raised an eyebrow. "Is there any more specific difference?"
Yoriichi paused briefly before answering.
"Among everyone I've seen, I am the only swordsman who manifested a Slayer Mark before twenty-five and still lived to old age.
I've seen many who awakened it before twenty-five, but all of them died at that age, or even earlier when their bodies gave out. As for those who awakened it after twenty-five, none survived more than ten hours.
So my understanding of the Slayer Mark ends there. My assessment of Muichiro is based on comparisons with Mist Breathing swordsmen across generations and those who have awakened the mark. At best, it is about eighty percent accurate."
"Eighty percent…" Hiru turned to Tanjiro. "What about you? I mean the effect of the Slayer Mark on your body."
Seeing everyone looking at him, Tanjiro touched the mark on his forehead.
"I think I activated the Slayer Mark before turning into a demon, so it's still active now. But… it feels strange.
Even when I was a demon, I could feel the mark constantly draining my body while active. But after turning back into a human, that subtle sense of drain has completely disappeared. I don't know if my senses have dulled or not, but right now… I feel perfectly fine."
"I see… Activate it. Let me take a look."
"Yes, Teacher."
Tanjiro activated the Slayer Mark even faster than Muichiro. The moment he finished speaking, the mark spread from his temple. However, unlike before, when it covered his entire face in bright crimson during his demon state, it now extended only slightly forward, and its color was dim.
"…Open the Transparent World."
Yoriichi observed him for a moment before letting out a quiet sigh.
"That's enough. You can stop."
"So? What's the difference between the two?" Hiru asked.
As the mark on Tanjiro's forehead faded, Yoriichi turned to him.
"The Slayer Mark no longer affects Tanjiro's body. In other words, he is now like someone born with it. Unless he contracts a serious illness, the mark will not drain his strength.
"I also compared the differences between his body and Muichiro's… but unfortunately, this is not something that can be achieved through training. It cannot be widely replicated."
"So his body structure changed when he turned back from a demon into a human?" Hiru glanced at Tanjiro, who looked completely innocent, then turned to Muichiro and ruffled his hair, a hint of apology in his expression.
"Muichiro, you'll have to rely on your own efforts… I did promise I wouldn't turn humans into demons."
"Don't worry!" Muichiro said confidently, patting his chest. "I've already learned how to activate it. There's no reason I can't learn how to deactivate it too. After the final battle, I'll learn from Tanjiro how to shut it off. I've got plenty of time!"