The Magic Power Refinement Method of Breathing Techniques That Doesn't Require Magic Circuits

From Sakonji Urokodaki's perspective, Dan Lei had martial arts skills on the level of a Celestial Realm expert, yet didn't learn from him. Instead, he'd come all the way out here to study Breathing Techniques. It was like abandoning a mountain of gold at his feet to dig for copper in the wilderness. Calling it throwing away a watermelon to pick up sesame seeds didn't even begin to describe it.

After all, Giyu Tomioka's letter had clearly stated that this Mr. Kojiro Sasaki would probably need only two strikes to defeat him.

And after meeting Kojiro Sasaki, Sakonji Urokodaki had said that if it were him, he probably wouldn't be able to withstand even one strike.

That was because, no matter how hard Sakonji Urokodaki tried along the way, he couldn't detect Kojiro Sasaki's presence. But Dan Lei only had to wave or call out, and Kojiro Sasaki would appear beside them in an instant.

The man could appear during the day, had a shadow in the sunlight, and, though he was somewhat taciturn, could respond normally when Dan Lei spoke to him. So he couldn't possibly be a demon.

In Sakonji Urokodaki's understanding, if someone wasn't a demon, they could only be a living person. His inability to detect Kojiro Sasaki was simply proof of the absolute gap in their abilities. After all, he himself could do much the same thing to ordinary people.

However, Dan Lei wanted to learn Breathing Techniques not for the swordsmanship, but to experience firsthand the feeling of producing elements through breathing, understand how it worked, and see whether it could be of use to him.

Kojiro Sasaki's Rockstream Sword Style couldn't do that. His Swallow Return Sword Technique could only teach the version available to ordinary people, which certainly wouldn't achieve the effect of Noble Phantasm Dimensional Slash.

So when Dan Lei saw how baffled Sakonji Urokodaki looked, he hurried to explain.

"Mr. Sakonji Urokodaki, I think you may have misunderstood. I want to learn Breathing Techniques because I'm curious about the method that lets ordinary people unleash elemental attacks.

"To be frank, my abilities may seem miraculous, but they require an extremely high level of talent.

"I'm not bragging, but out of a hundred million people, you wouldn't find a single one with the same level of elemental affinity as me.

"So if we could figure out the principle behind allowing ordinary people with low elemental affinity to use elements, it would be extremely valuable."

Hearing Dan Lei put it that way, Sakonji Urokodaki found the idea much easier to accept, and he felt more at ease with Dan Lei as well.

After all, people who humbly learned from those with lesser abilities and sought to absorb their strengths were modest. Such people were rarely truly bad.

Still, Sakonji Urokodaki didn't agree on the spot. He explained that Breathing Techniques were the property of the Demon Slayer Corps, and that he needed approval from his superiors before teaching them to an outsider.

Dan Lei knew that Breathing Techniques weren't actually considered the property of the Demon Slayer Corps. As long as they were used to slay demons and not to commit evil, a cultivator could teach them to someone outside the Corps without much trouble.

Fortunately, as a member of the Longevity Species, Dan Lei had plenty of patience. And from what he knew of the Demon Slayer Corps, they probably wouldn't refuse. They supported anything that helped slay demons. So he replied,

"That's reasonable. I arrived unexpectedly, and you don't know much about me.

"Still, please pass along my greetings to your organization's leader in your letter.

"And please tell your leader that cooperation begins with making contact. You can consider this a trial run for cooperation between me and the Demon Slayer Corps. My investigation into demons won't be completed in just a year or two. Time will prove everything."

Seeing how reasonable Dan Lei was, Sakonji Urokodaki's regard for him rose even further. He said he would make sure to explain the situation and its implications clearly in his letter.

Sakonji Urokodaki had no desire to offend Dan Lei. The man had a superlative fighter at his side. If Kojiro Sasaki really was his bodyguard, then Dan Lei's status had to be unimaginably high for him to employ someone of that caliber.

Just as Dan Lei had expected, the Demon Slayer Corps approved his request to learn Breathing Techniques with remarkable ease. Tanjiro's injuries from triggering traps all the way down the mountain hadn't even healed yet when a letter arrived agreeing to cooperate.

The letter also stated clearly that, if Dan Lei wished, they could find someone to teach him any of the five basic styles of Breathing Techniques.

But Dan Lei didn't want to bite off more than he could chew. The Sustainer Dragon Clan excelled at controlling water, so he decided to master Water Breathing first, understand the principles behind Breathing Techniques, and then consider whether to learn any others.

Dan Lei showed off another one of his abilities. He healed Tanjiro, who had been covered in wounds and would otherwise have needed several more days of rest, in just a few minutes.

To Sakonji Urokodaki, the healing power of the Abundance Destiny was practically capable of bringing the dead back to life and restoring flesh to bare bones. Long wounds that had only just scabbed over healed completely in a matter of seconds.

Of course, Dan Lei knew that the power of the Abundance Destiny was, in essence, the conversion of vitality from one source to another. The Power of the Path could amplify that vitality and make the conversion more efficient, allowing injuries to heal quickly—and any kind of injury could be treated.

Of course, the Imaginary Energy of the Abundance Destiny could also replace expended vitality. But that was beyond what a Pathstrider of Dan Lei's level could do.

As the one casting the spell, if Dan Lei didn't use his own vitality or medicine, healing would consume the injured person's vitality.

That was no problem for minor injuries. A bit more meat or a little extra sleep would make up for it. But if he did that with a serious injury, the person would end up looking as though they'd gone hungry for days, even after being healed.

That was why the longevity granted by the Pharmacists of Abundance was a wicked path. Once a person's lifespan exceeded the blessing's limit, they had to plunder other lives to replenish their own. Otherwise, the Five Decays of the Celestial awaited them.

Of course, blessings came in different grades. The Celestials of the Xianzhou were at the very highest level, making all the other Abundance creatures green with envy. It seemed as if the lives of the Xianzhou natives were truly endless; even after thousands of years, they hadn't reached the limit of their blessings. To other Abundance creatures, the so-called Mara-struck state seemed more like a transformation of life than death.

In any case, after Dan Lei brought Tanjiro back from the brink, Tanjiro ate a huge meal and was able to start training that very day.

And so Dan Lei began receiving instruction alongside Tanjiro.

However, Tanjiro still needed to continue building his foundation, while Dan Lei went straight to learning Breathing Techniques.

The Sustainer Dragon Clan's bodies were simply too strong. Dan Lei almost learned Breathing Techniques the moment he began, and in less than a week, he had mastered producing streams of water through nothing but his breathing.

By then, Dan Lei had also confirmed the truth behind Breathing Techniques: they were a method of refining magic power that didn't require Magic Circuits.

Yes, when all was said and done, the elemental attacks produced by Breathing Techniques still relied on magic power—or, more precisely, a special kind of magic power called qi.

Unlike magicians, who absorbed magic power from the Great Source outside themselves through their Magic Circuits, practitioners of Breathing Techniques obtained magic power by inhaling air.

Through training, practitioners of Breathing Techniques developed lung capacity far beyond that of ordinary people, allowing them to take in a vast amount of qi in a single breath.

Air already contained particles of magic power. Those who had mastered Breathing Techniques could refine these particles in their respiratory tracts and lungs, turning them into a special gaseous form of magic power. This power flowed directly through the body's meridians, which were distinct from Magic Circuits, just like True Qi in martial arts novels.

That was the truth behind the claim in the anime that Breathing Techniques could enhance blood flow and send energy to every cell, increasing its vitality.

To be honest, before practicing Breathing Techniques, Dan Lei had never sensed that every blood vessel contained meridians dedicated to circulating energy. Xianzhou medical knowledge hadn't covered them either.

But once he had refined his Breathing Techniques to the point where he could achieve Total Concentration, the meridians circulating qi within his blood vessels became visible. They were located slightly below the Magic Circuits, but the two systems didn't conflict at all.

However, Breathing Techniques clearly had no concept of circulating qi through a full cycle. Once the energy converted from inhaled air ran out in the meridians, it was gone. Even if left unused, it would naturally dissipate into the body.

Still, it could passively strengthen the body to some extent. That was why mastering Total Concentration Constant and becoming able to unleash elements at will were prerequisites for becoming a Hashira.