For several consecutive days, the Hashira temporarily set aside their duties. Drawing upon their own breathing techniques and profound swordsmanship, they worked together with Tanjiro's verbal descriptions to try to recreate the Hinokami Kagura.
"According to Tanjiro, the Hinokami Kagura consists of twelve dance forms. Correspondingly, when converted into a breathing style, there should be twelve sword forms. We've largely managed to reconstruct them, and indeed, we can each find elements of our own breathing styles within these twelve sword forms. However…"
Shinobu Kocho frowned as she looked at the sheets of paper on the table, each one marked with human anatomical diagrams.
"The difficulty of this breathing technique is simply unbelievable. It demands inhuman levels of speed, strength, flexibility of muscles and bones, and balance. The five major breathing styles truly only selected certain aspects of this technique as their essence, lowering the difficulty to create their own forms."
Iguro Obanai spoke in a low voice.
"That's right. The first few forms are still within reason—the founders of the five major breathing styles were able to reproduce them within their own techniques. For example, the Water Wheel in Water Breathing and the Water Wheel in Hinokami Kagura are nearly identical in technique. The Raging Flame Whirlpool in Flame Breathing and the Blazing Sun in Hinokami Kagura mainly differ in breathing method. Some founders even further developed these techniques, making their own breathing styles even more dazzling. But the later forms…"
Tengen Uzui shook his head.
The later forms are simply beyond human capability. The physical requirements surpass the limits that normal humans can reach, even with breathing techniques. They demand an almost unimaginable degree of control and awareness over every muscle fiber.
Most crucially, none of them could master the specific breathing method Tanjiro taught.
Every attempt left them gasping for air, their lungs burning as if on fire.
No, it wasn't just burning—it was as if molten iron was being poured directly into their lungs.
Yet Tanjiro himself, though unable to fully perform the Hinokami Kagura breathing technique, was limited only by his still-developing cardiopulmonary function.
He could actually use this breathing technique in short, intermittent bursts. Apparently, he had realized this while chopping firewood, which explained how he could chop so much wood at the age of twelve.
It wasn't until recently that he realized he'd been unconsciously using the Hinokami Kagura breathing method while working.
"It's truly difficult."
Even Hardy couldn't do it.
Surprisingly, it was Kyojuro Rengoku, who had just returned from Kyoto Prefecture, who picked it up the fastest.
After returning, Rengoku had earned the title of Flame Hashira by slaying Lower Moon Two and joined in the effort to restore the original breathing technique.
Thanks to his younger brother Senjuro's discovery in the Rengoku family archives, the Demon Slayer Corps learned the true name of Sun Breathing. However, the records stated that Sun Breathing had thirteen forms, while Hinokami Kagura had only twelve.
Hardy, of course, knew that combining the twelve forms created the thirteenth, but for now, only Kyojuro Rengoku could barely perform the first two forms. The others couldn't even maintain the Sun Breathing technique.
Until someone mastered the first twelve forms, this information was of little use.
Could it be that, like Tanjiro and Kyojuro Rengoku, only those with red hair and red eyes, whose families had worked with fire for generations and were "Children of the Flame," could learn Sun Breathing?
Probably not. After all, Yoriichi and Michikatsu Tsugikuni were twins—if one was a Child of the Flame, so was the other.
Although no one had yet mastered Sun Breathing or figured out the exact requirements for learning it, there were still valuable insights to be gained.
As the source of the five major breathing styles, studying Sun Breathing gave Hardy new inspiration on how to combine Wind Breathing and Thunder Breathing.
In the forest, Hardy gripped a branch, a swirling wind gathering in his hand, mingled with crackling lightning that danced along the wood.
At this moment, chakra proved more useful than breathing techniques. Compared to breathing, chakra was closer to a tangible substance and easier to control and sense.
This inspiration came from his DC World counterpart, who, after studying the Hinokami Kagura, began to theorize:
"By rapidly circulating wind, using friction and compression of air to create pressure changes, then channeling electricity to generate high-voltage ionization, you can produce high-energy, high-temperature plasma—similar to the solar wind."
The swirling wind was continually compressed, the lightning within growing denser and brighter, emitting a sizzling electric sound.
"Bang!"
The withered branch serving as a conduit shattered with a crash, instantly vaporized by the superheated plasma and becoming part of it.
Hardy frowned slightly, quickly tossing the plasma skyward and flashing backward.
"Boom!"
A deafening explosion erupted, a small blue sun bursting in the sky, shaking everyone's eardrums.
"Hey, hey, hey! What's going on now? I just finished a mission and there's already such a commotion."
Sanemi Shinazugawa strode over, carrying his Nichirin Blade and baring his muscular chest.
"Whoa… what terrifying power."
Muichiro Tokito stared blankly at the blue sun in the sky.
The other Hashira, drawn by the noise, also came over.
"Such dazzling, magnificent power," Tengen Uzui couldn't help but exclaim.
His Sound Breathing, combined with explosive beads, produced spectacular effects in battle, but compared to this, it paled in comparison.
"By the way, I've never seen this breathing technique before. Hardy, did you create it yourself?" Shinobu Kocho asked curiously, taking out her stethoscope as she approached Hardy.
Hardy waved his hand, indicating it wasn't necessary.
This body—
Although the amount of chakra in the clone had increased, it was still far from matching the original body. Just now, in order to maintain the plasma orb and delay its explosion, a large amount of chakra had been consumed.
"I suppose you could say that, but it's still not perfected—otherwise, such mistakes wouldn't have happened."
Hardy shook his head.
If he had succeeded just now, he might have been able to fuse Wind Release chakra and Lightning Release chakra, potentially developing a new kekkei genkai.
Although he failed, at least he had found a possible path forward. As long as he continued to deepen his mastery of Wind and Lightning Release ninjutsu, success was only a matter of time.
Before that, as Shinobu Kocho suggested, he might as well try to combine Wind Breathing and Thunder Breathing to create a new breathing technique.