The name yoriichi zero reminded Haruto of a name that once appeared in the bullet comments.
Yoriichi Tsugikuni.
"Was he from the Warring States Period?" Haruto's gaze fixated on the Nichirin flower paper earring on the mechanical doll's ear, and a flash of inspiration struck him.
It was the same earring as… Tanjirou's… From the bullet comments, this Yoriichi Tsugikuni should be someone who brought a heavy shadow to the Demon King Kibutsuji Muzan, otherwise, there wouldn't be various bullet comments like "Muzan's heart stopped" whenever his name appeared on the screen.
So… did Muzan send people to look for Tanjirou because Tanjirou was related to this swordsman from the Warring States Period?
Because of the same earring?
Is the Kamado Family a descendant of Yoriichi Tsugikuni?
Kotetsu scratched his head and mumbled, "He was indeed a very active swordsman during the Warring States Period, but I don't know much else, after all, it was so long ago…"
It was a long time ago, perhaps Miss Tamayo would know, after all, her age… coughcough.
Haruto helped move the mechanical doll to an open space, with Kotetsu following behind, muttering and drawing on paper.
"I've studied it for a long time and still can't figure out its structure. Our ancestors' wisdom truly hasn't been passed down to their descendants at all…"
"This mechanical doll has lasted over three hundred years. Won't it break if it's reactivated?" Haruto gently placed the doll on the ground. "What if it breaks? Can you fix it?"
"…" Kotetsu stopped his drawing and writing, put his hands on his hips, and angrily said, "I'm just a six-year-old kid! Don't you dare hope that I can fix this big guy!"
He puffed up for a while, then his shoulders slumped. "If it breaks… I'll just study harder and fix him…"
Since he said so, Haruto no longer fussed, standing aside with his wooden sword, waiting for Kotetsu to take the key from his neck and activate the mechanism.
"You should change your sword. This mechanical doll is very powerful, and in his hands is a real nichirin blade forged by my ancestors."
"My sword is broken." Haruto shook his head indifferently. "It's fine, just go ahead and activate it. I'll dodge, so nothing will happen."
"Are you sure?"
"Absolutely!"
Kotetsu inserted the key into the keyhole on the doll's neck, then quickly backed away.
Haruto gripped his wooden sword, staring intently at the mechanical doll.
"Buzz~"
Huh? What's going on? Why is a whirlwind blowing in front of him?
The speed of the six-armed mechanical doll exceeded Haruto's maximum imagination. Almost immediately after activation, he swung his nichirin blade and appeared in front of Haruto.
"Clang!"
A flash of gleaming blade light grazed his eyes, and the wooden sword in his hand snapped in two.
Haruto: =͟͟͞͞(꒪⌓꒪*)
Before he could utter a single word, the mechanical doll showed no pause, and six long blades shimmering with cold light slashed towards him.
"Eek!"
Haruto lightly tapped the ground, soaring up like a hawk, dodging the wheel-like rain of blades.
Damn it, without a sword in hand, he could only dodge; he couldn't possibly use his flesh and blood to pass through the blade light and strike the doll's head!
He hugged his knees in the air, spun a few times to the left, and landed lightly. But the doll followed, its exquisite swordsmanship making it impossible for Haruto to stand firm; he could only passively change his steps with the doll's offensive.
"What a powerful swordsman!" Haruto gritted his teeth and shouted, "What kind of monster is this! Why does he have six arms!"
"The book says that because the doll's prototype was too powerful, our ancestors could only barely imitate his movements from back then by adding four more arms when forging the doll…" Kotetsu replied, "But so many arms will cause other movements to deform, so this doll is still far from being as good as that swordsman!"
The tip of the blade grazed Haruto's face, and the white-haired swordsman moved nimbly like a rabbit and a falcon, his unbuttoned Demon Slayer Corps uniform becoming his biggest hindrance.
No matter how strong the doll was, it was still just a doll. Haruto constantly observed the movement patterns of yoriichi zero while dodging.
Kotetsu stood aside, lost in thought.
Haruto-elder brother wasn't bragging.
In terms of swordsmanship alone, he was indeed the strongest among the swordsmen who had come to the Swordsmith Village over the years.
If compared to Himejima-san, one could only say that the two excelled in different areas.
Himejima-san's swordsmanship was powerful and courteous, with broad, sweeping moves. Coupled with a meteor hammer and chain axe made from a large amount of tamahagane, one swing could crush the head of a powerful demon into powder.
Haruto-elder brother's swordsmanship, however, was a different kind of powerful.
His figure was light, his footwork excellent, and every muscle on his body seemed capable of determining the course of the battle. His movements were very detailed, and he was best at using his muscles to make incomprehensible and unpredictable changes in movement.
It was said that the characteristics of his Breathing Technique moves were also speed and unpredictability. Such a shadow-like swordsman, if hidden behind a mountain-like Himejima-san, would deliver a fatal blow to demons.
After a long struggle, Haruto finally found an opportunity in the gaps between the doll's blades.
His two legs, like a pair of scissors, threaded through the blades and fiercely clamped the doll's head. With just a push of his legs, he could completely destroy this three-hundred-year-old masterpiece of artisan wisdom.
But he saw the pitiful eyes behind the Fire Man mask, so he released his strength, kicked the doll in the chest with his foot, sending it flying far away.
He himself rolled lightly onto the grass, patting off the grass stalks clinging to his Demon Slayer Corps uniform.
Kotetsu quickly approached the doll, removed the key from its back neck, and carefully inspected the doll.
"Phew…" Haruto twisted his neck, swinging his fists forward with exhilaration. "So strong, I feel like all my bones have stretched out."
Just a replica, a mechanical doll without a swordsman's mind, could fight him for so long. How much stronger was its prototype swordsman… And yet, such a powerful swordsman couldn't kill Kibutsuji Muzan?
Haruto shook his head, shaking off the meaningless thoughts.
Kotetsu, having finished inspecting the doll, also breathed a sigh of relief. "No damage, what a stroke of luck. But Haruto-elder brother, this isn't the doll's strongest power yet."
With sparkling eyes, Kotetsu described in detail to Haruto the correct way to use the doll. By rotating the mechanical doll's wrists and fingers in a certain order, it would perform corresponding movements.
As a doll capable of participating in actual combat training, this design allowed it to focus its attacks on a specific swordsman's weaknesses and shortcomings under its master's arrangement, maximizing the doll's power.
"I heard Wind Pillar-sama say that newly appointed swordsmen… including those who joined the Demon Slayer Corps even earlier than him, are getting worse and worse in strength. I don't even know how they passed the selection." Kotetsu said, stroking the Fire Man's mouth. "If I could also design a mechanical doll like yoriichi zero, I could let out some steam… ah no, contribute a little to the training of new swordsmen.
Then I'll also design a doll, based on Haruto-elder brother, and call him… Haruto Zero! How about that?"
Haruto chuckled and patted his head. "Of course, that's good… but how about Haruto One instead?"
"Eh?"