The conditions to awaken the Transparent World, true to its nature, remained vague and ambiguous.
It was said that one could awaken this ability after giving their all and enduring pain, but just like the Demon Slayer Mark and the Bright Red Nichirin Sword, had no one else fulfilled these conditions before?
Certainly not.
What this world didn't lack was people who had given their all and endured immense pain, but how many of them had awakened the Transparent World among them?
For this reason, the Transparent World must also have other conditions to awaken. Otherwise, Akaza wouldn't have pursued this domain for over a hundred years, only to come up empty-handed.
Many Hashira successfully awakened the Demon Slayer Mark and the Bright Red Nichirin Sword in the original work, but when it came to the Transparent World, the number of people who could awaken it was scarce, only two to three people.
Therefore, in Riezel's view, the Transparent World should be considered the most difficult of the three abilities to awaken.
In the original work, there was a flashback scene where Tanjirou's father mentioned the Transparent World.
—The important thing is the right breath and the right movement.
—In the beginning, you must remember the movement and the feeling, pick up these elements, open your five senses, and understand your entire body shape down to every blood vessel.
—At this moment, it will truly be painful, feeling like continuing to struggle will only lead to a dead end. But after remembering and absorbing many things, remove unnecessary parts, leaving only what is necessary for the movement, and close off the rest.
—When people want to listen carefully to a sound, they close their eyes, right? Similarly, choose the most necessary thing in that instant.
—Over time, the opening and closing of blood vessels and muscles in the body will be as simple and rapid as blinking, and then the light will appear, and the path will open.
—When the mind becomes transparent, you can see the Transparent World, which is the domain reached after giving your all and enduring pain.
From what Riezel knew, this scene was probably the most detailed information mentioned in the original work about how to awaken the Transparent World.
It was also because of recalling this past memory that, at the end of the story, Tanjirou successfully awakened the Transparent World.
Referring to this memory, combined with his own practical experience, Riezel ultimately concluded.
'I can awaken the Transparent World probably because during the evolution of Sun Breathing, I gradually understood the correct breath and movement. Furthermore, to ensure the smooth flow of my breathing and magical energy throughout my entire body, I maximized the use of my five senses, which in turn, helped me comprehend my entire body shape down to every blood vessel.'
'In this situation, the pain I felt at that time might not only have been due to the attempt at evolving Sun Breathing but also because unknowingly, I touched upon the conditions for awakening the Transparent World.'
'And then, after three months, as the evolved Sun Breathing gradually completed, my body subconsciously remembered all the essentials and movements. In the end, I naturally learned how to concentrate, shutting off unnecessary senses, clearing my mind, and enabling me to use the Transparent World.'
Until this point, Riezel finally understood why he could directly awaken the Transparent World. So, after taking this into account, he began to summarize the method to awaken the Transparent World.
'Firstly, one must learn to concentrate, intensely so, allowing one's senses to expand, fully recognizing the correct shape of the human body, reaching the point where even every blood vessel can be distinctly felt.'
'Endure the torment brought upon the mind and nerves by this intense concentration, until one can adeptly switch their senses and shut down unnecessary ones.'
'When the nerves withstand unbearable pain brought on by intense concentration, they become resilient, undergo a transformation, and the mind becomes transparent.'
'At that moment, the Transparent World is born...'
'I see, the trick lies in concentration!'
Riezel grasped the crucial point.
Clearly, this theory was also confirmed in the original work.
In the original work, Gyoumei, Muichirou, and Obanai eventually awakened the Transparent World.
At that time, it was because they wanted to see through their opponent's movements, focusing all their attention on identifying their enemy's weaknesses, that they successively awakened the Transparent World.
Having unparalleled concentration, fully expanding one's senses, adeptly controlling and dominating, and freely opening and closing—the Transparent World would awaken.
"All of you, concentrate!"
Riezel deliberately began training the Hashira in this aspect, but as mentioned earlier, there were no shortcuts this time.
The awakening of the Demon Slayer Mark could be triggered by someone who already awakened it, and the Bright Red Nichirin Sword would naturally awaken after the Mark was activated. Only the Transparent World required a solid understanding and meeting the conditions step by step to succeed.
Because of this, even though Riezel consciously tried to guide all the Hashira to understand, after several days, no one succeeded in awakening the Transparent World.
Riezel continued to spar with them, guiding them in battle, pressing them with each encounter, and teaching them to focus during combat.
Such days lasted for a whole week.
However, for the entire Swordsmith Village, this week was filled with discussion.
===
*BOOOM!*
Near the Swordsmith Village, flames suddenly soared into the sky without any apparent reason, accompanied by a rumbling sound that shook the entire village.
Almost everyone in the village heard the thunderous roar.
However, instead of being startled, they began to discuss spiritedly.
"Seems like it's that time again, huh? Lord Head Instructor and all the Hashira are at it with their special training."
"Whenever they train, it always stirs up such a fuss. They're truly the toughest swordsmen in the Demon Slayer Corps."
"I heard it's because Lord Head Instructor is whipping the current Hashira into shape, hence the loud noises."
"Ahh, that explains it."
Chatting like this with each other, the swordsmiths remained calm amid the commotion.
At first, they had been panicked.
As they heard the sudden rumble and unexpected explosion, the people of the Swordsmith Village thought that demons were attacking, almost causing chaos.
However, after a week of daily explosions and thunderous noises, they had grown accustomed to it. Especially after learning that the instigator was the new head instructor of the Demon Slayer Corps, the swordsmiths were even more understanding.
"So it's the master of the divine sword showing off, no wonder."
Indeed, in the eyes of the swordsmiths, Riezel was almost synonymous with omnipotence.
After all, the appearance of Hermit had elevated his status in their eyes to that of a god, leading to a subconscious belief that, no matter how exaggerated his actions were, they were normal.
Moreover, those who had seen Hermit knew that it emitted super high temperatures. In the hands of its master, a casual swing could ignite a massive fire, as if a god of fire had descended.
Such understanding led the swordsmiths to believe that the flames and explosions erupting repeatedly were caused by the master of the divine sword.
As a result, their attitude toward Hermit became increasingly fervent, and their respect for Riezel also grew.
Of course, the members of the Demon Slayer Corps had a different perspective.
"What? Lord Head Instructor is training the Hashira?"
"Huh? They still need training?"
"Wait, the flames and noises are caused by the head instructor? Seriously?"
"No fucking way!"
Indeed, this was the reaction of the members of the Demon Slayer Corps.
Having spent considerable time in the Demon Slayer Corps and with Riezel having appeared for less than a few months, how could they know how strong he truly was?
Even if some claimed that Riezel had single-handedly slain multiple Upper Ranks during the demon invasion, it was merely an astonishing feat to hear about. Without witnessing it firsthand, they couldn't feel its impact.
In contrast, it was the Hashira they felt awe for.
Many in the Demon Slayer Corps had seen the Hashira display their prowess, even many Kakushi had witnessed the battles of the Hashira with their own eyes.
In their eyes, the Hashira were undoubtedly powerful figures, akin to gods. Even the Lower Ranks of the Twelve Kizuki were not their match.
Because of this, whether they were Demon Slayers or the Kakushi, they all greatly respected the Hashira. Many couldn't help but kneel and bow their heads in front of the Hashira, showing reverence in their demeanor.
Yet, someone told them that powerful figures like the Hashira had been taken for special training by the current head instructor?
It was hard not to doubt the truth of this.
However, this doubt completely disappeared a few days later.
The reason was simple.
After nearly a month, the training ground near the Swordsmith Village was finally completed, allowing all members of the Demon Slayer Corps to enter for training.
Needless to say, on the first day the training ground was officially opened, they witnessed a scene that was truly unforgettable and awe-inspiring.
*BOOM!* *BOOM!* *BOOM!*
Amidst rumbling sounds, the powerful Hashira, who were akin to gods in their eyes, were blasted out by explosions, falling to the ground and rolling a great distance in a sorry state, one by one.
Moreover, in the center of the explosions, Riezel stood still, holding a Nichirin Sword shimmering with a red light that emitted high temperatures, reprimanding the fallen Hashira.
"How many times have I told you, don't just rely on your eyes and intuition to observe my movements, open all five senses, observe yourself first, then observe me!"
"Discard unnecessary movements, discard unnecessary perceptions, concentrate!"
"Focus!"
"Again!"
Under Riezel's reprimand, all the Hashira staggered to their feet one by one, covered in dust and ash, looking extremely pitiful.
Even Shinobu and Mitsuri, who were regarded as goddesses, now looked like two little mongrels, with a dusty and dirty appearance.
""HAAAAHHHHHH—!!!""
All the Hashira shouted in unison, attacking Riezel together once again.
*BOOOM!*
After the loud noise, with the explosion sweeping through, they were once again thrown out like trash, rolling to the ground.
Witnessing this scene, the members of the Demon Slayer Corps were stunned senseless.
Inevitably, they looked toward Riezel with fear in their eyes.
"He actually subdued all the Hashira...?"
From that day on, no one questioned Riezel's strength anymore.