Learning the Breathing Technique (Seeking Readership)

Lord Dan Lei's flames, which utterly reduced the demon to ash, truly earned Sakonji Urokodaki's respect.

Given the industrial capabilities of the Taisho era, there was no way the Demon Slayer Corps could produce flames of 2000 degrees—even reaching 1000 degrees would have been a stretch.

In the anime, the flames wrapped around Kyojuro Rengoku's blade as the Flame Pillar failed to trigger a Scarlet Blade, proving his fire wasn't hot enough to make the Nichirin Blade's metal glow red.

There was a technique in the original work that relied on clashing Nichirin Blades together to generate a momentary burst of heat, meaning the temperature needed to redden the metal wasn't excessively high—otherwise, such a method would never reach the required threshold.

Though it was unknown exactly how many degrees the Nichirin Blade's metal needed to turn red, based on the "red-hot" state of ordinary metals requiring 500 to 800 degrees, the forging temperature couldn't have exceeded 1000 degrees by much; otherwise, with the craftsmanship of this era, how could ordinary smiths mass-produce so many Nichirin Blades?

The Demon Slayer Corps had certainly tried burning demons to death with fire, and it had certainly failed.

So when Lord Dan Lei used 2500-degree flames to incinerate a demon, Sakonji Urokodaki found it utterly inconceivable, directly deeming it Divine Fire.

As for Kojiro Sasaki, Sakonji Urokodaki hadn't even sensed when he'd taken his stand there, and even with him right before his eyes, he still couldn't perceive his presence—he naturally acknowledged this as the legendary state of Oneness with Nature.

Seeing that Sakonji Urokodaki was convinced, Lord Dan Lei naturally adopted a friendly demeanor, returning the greeting and saying, "Sakonji Urokodaki-san, I've long admired you.

I imagine Giyu Tomioka-san has already explained the matter to you. We'll be imposing on you for a while."

Finding that Lord Dan Lei didn't put on any airs of a superior, Sakonji Urokodaki naturally didn't hold himself aloof as he had when first meeting Tanjiro, immediately stating that it was a good thing Lord Dan Lei was willing to study demons, and that providing a place was his duty.

During this mutual flattery between Lord Dan Lei and Sakonji Urokodaki, Tanjiro had already buried the deceased from the temple with Nezuko.

Nezuko was very strong, and there were everyday tools like iron shovels in the temple's backyard, so they worked quickly.

After burying the bodies, Tanjiro offered a routine prayer and naturally came to find Lord Dan Lei, just in time to see him speaking with a man wearing a Tengu mask.

Seeing that Tanjiro had finished burying the dead, Lord Dan Lei naturally introduced him to Sakonji Urokodaki:

"Sakonji Urokodaki-san, this young man is Tanjiro, and the one behind him is Nezuko. I can vouch that she hasn't gone berserk even once these past few days."

However, upon hearing Lord Dan Lei's words, Sakonji Urokodaki didn't immediately voice his opinion. Instead, he walked slowly up to Tanjiro and said, "I am Sakonji Urokodaki. Tanjiro, I ask you: if your sister were to eat a person, what would you do?"

Faced with this question, Tanjiro was naturally stunned. He absolutely couldn't accept his sister eating a person, because he knew eating people was evil, yet he couldn't bear to harm his sister.

But that very hesitation earned him an immediate slap from Sakonji Urokodaki, followed by a scolding:

"Unacceptable! Your judgment is too slow! Your whole body screams indecision! Your resolve isn't firm at all!

If your sister eats a person, there are only two things you must do: kill your sister! Then take your own life! That's what it means to have a sister who's become a demon.

So remember this: never let such a thing happen, never allow your sister to take the life of an innocent person!"

Tanjiro was dazed by the slap, and instinctively looked toward Lord Dan Lei, who had become something of a pillar of support over the past two days.

But Lord Dan Lei spoke just as sternly at that moment:

"Tanjiro, don't look at me.

Sakonji Urokodaki-san is right. If your sister eats a person, the best thing you can do is kill her before that happens.

If you can't do it, I will.

If I'm no longer by Nezuko's side at that time, I'll rush back the moment I learn of it and finish her off.

Then, I'll leave myself a scar that will never fade, and remember this for the rest of my life.

And don't look to me for everything. I'm just a passerby in your life; sooner or later, I'll leave. You need to learn to stand on your own. Otherwise, after I'm gone, when something happens, are you going to ask Nezuko, who can barely express herself clearly now?"

Hearing this reprimand from Lord Dan Lei, Tanjiro's eyes instantly cleared. He stood up straight and answered earnestly, "Yes, I understand!"

Seeing that Tanjiro had grasped his meaning, Sakonji Urokodaki continued to address him:

"Giyu Tomioka has told me about your situation and recommended you for the Demon Slayer Corps.

So, following procedure, I'll test whether you can become a swordsman who slays demons.

Put your sister in the box, carry her on your back, and follow me."

After saying this, Sakonji Urokodaki also spoke to Lord Dan Lei:

"Lord Dan Lei and Kojiro Sasaki-dono, please follow This Humble One as well."

With that, Sakonji Urokodaki began a steady jog along the country path.

It was clear that Sakonji Urokodaki was testing Tanjiro here, so he didn't run fast. With Lord Dan Lei's physical constitution as a member of the Sustainer Dragon Clan, he kept up easily, while Kojiro Sasaki, finding it too slow, simply turned into a Spirit Body.

As for Tanjiro, he had to run at full speed while carrying the box on his back to keep up.

Still, as a charcoal seller who often had to haul loads of charcoal down from the mountains to sell and return the same day, Tanjiro's stamina was adequate.

And whenever he felt he couldn't go on, he would think of Nezuko in his mind, using love to encourage himself to persevere.

Thus, from dawn to noon, from noon to evening, with only a few breaks for food and water, Tanjiro made it to the front of Sakonji Urokodaki's house.

In truth, for an ordinary Demon Slayer Corps swordsman selection, Tanjiro's performance so far would have already passed.

But as a Trainer, Sakonji Urokodaki had already lost 13 disciples in the Final Selection.

This had made Sakonji Urokodaki doubt his own teaching ability and made him stricter in selecting disciples, since sending out someone lacking in strength was simply sending them to their deaths.

So, Sakonji Urokodaki still had one final test for Tanjiro: a timed run from a trap-laden mountain, surviving all the way down to the house at its base.

But this time, he didn't have to bring Nezuko along. Dan Lei had Kojiro Sasaki appear and told him to wait at the foot of the mountain, while he himself went up the mountain with Sakonji Urokodaki.

Here, Dan Lei wasn't going up the mountain to watch Tanjiro's test process. Instead, after Tanjiro started the test, he took the chance while descending the mountain to say to Sakonji Urokodaki, "Lord Sakonji Urokodaki, please forgive my impertinence. When you teach Tanjiro the Breathing Technique, could you also teach me? I'll repay you with my research materials on demons."

Dan Lei's words directly made Sakonji Urokodaki stumble, nearly falling flat on his face. After steadying himself, he clearly complained with some exasperation, "Lord Dan Lei, with a Celestial Realm expert like Lord Kojiro Sasaki by your side, do you still need to learn the Breathing Technique from me?"