The morning sun, filtered through the wisteria trellis in the Butterfly Mansion courtyard, cast dappled light.
Cheng Mo stood on the veranda, watching Tanjirou's sweat-drenched figure in the courtyard.
The wooden sword in the boy's hand cut through the air, emitting a steady whoosh.
Each strike was precise and powerful.
His breathing was long and steady, with hardly any perceptible pauses for breath.
In these two months, Tanjirou's progress had been remarkably fast.
The Qi Refining Technique had laid a solid foundation far exceeding that of ordinary people, and his Breathing Technique had also approached the threshold of Total Concentration: Constant.
This speed was far faster than the two years it took him in the original story to reach a similar state.
Cheng Mo knew in his heart that this was not only the result of Tanjirou's own talent and hard work but also the contribution of the Qi Refining Technique and modern training concepts.
Of course, it was also inseparable from his own 'high-pressure' training method, which incorporated subtle Chakra stimulation.
Cheng Mo's thoughts, however, were not entirely focused on Tanjirou's progress.
His conversation with Blackwing last night resurfaced in his mind.
"Master, the root of Blood Demon Art is by no means a simple physical mutation. Both the vague records passed down by my clan and my perception of that 'Snow Woman' point to one conclusion..."
"The characteristics of the soul are the true foundation that drives those myriad strange abilities."
Blackwing's deep voice seemed to still echo in his ears.
"If we can decipher the mystery of the soul's fusion with demon blood, perhaps we can truly retain part of the regeneration ability while reversing demonization, or even... tame the Blood Demon Art."
This possibility excited Cheng Mo.
But the reality was, he had scoured the Butterfly Mansion and the ancient texts he had obtained from Ubuyashiki, and the records concerning 'the soul' were all vague.
They were either myths and legends or vague philosophical speculations, with no practical research paths.
It seemed the key still lay with the Ubuyashiki Clan.
Their millennia of research must have touched upon the soul level.
The creation of Kasugai Crows and the 'Heart Reflection' secret art all proved this point.
But he immediately dismissed the idea of forcibly taking it by force.
The subtle sense of restraint emanating from the myriad realms compass reminded him.
Excessively violating the principle of 'positive interference' could lead to unpredictable consequences, even affecting the settlement of space-time coins.
He could only plan for the long term and wait for the right moment.
It's just... time was running out.
Cheng Mo sensed the myriad realms compass in his mind; only one month remained until forced return.
The rat hiding in the dark was extremely cautious.
He had been waiting for it for days, yet it managed to resist showing itself.
Cheng Mo didn't want to waste precious space-time coins just to extend his stay for fishing; it was too uneconomical.
He had to change his strategy, make the fish feel safe, and bite the hook voluntarily.
Tanjirou just finished a set of exercises, sheathing his sword and catching his breath.
He saw Cheng Mo and immediately flashed a bright smile: "Teacher!"
Looking at the boy's solid physique and his clear, determined eyes, a plan quickly formed in Cheng Mo's mind.
In the afternoon, the pharmacy was filled with the strong scent of medicine.
Kochou Shinobu was carefully counting the dried herbs.
Tanjirou was helping on the side, vigorously pounding herbs in a stone mortar, his movements rhythmic.
"Tanjiro-kun, you're really amazing."
Kochou Shinobu paused, looking at Tanjirou with her usual gentle smile.
But her eyes held genuine surprise: "Teacher Cheng Mo's training is so rigorous, yet you've managed to persevere and progress so quickly."
"You know, it's only been two months since you started training, hasn't it? Not everyone is a genius like Muichiro."
Tanjirou stopped pounding medicine and awkwardly scratched the back of his head.
His cheeks flushed slightly: "Thank you for the compliment, Miss Kochou, but I still have a long way to go! It's all because Teacher taught me so well, and Mr. Rengoku and Mr. Tomioka also guided me."
"I just don't want to let everyone down, and... I must become stronger!" He thought of his family, and his sister who was practicing in the deep mountains, and his eyes became firm.
Just then, Cheng Mo's figure appeared at the pharmacy door.
"Tanjirou," he called out.
"Teacher!" Tanjirou immediately stood up straight.
"Pack your bags, I'm taking you back to Peach Mountain."
Cheng Mo's tone was as calm and direct as ever.
Tanjirou paused, blinked, and asked curiously: "Peach Mountain? Is that... Teacher's sect, where old Mr. Kuwajima Jigorō is, right? Has something urgent happened?"
Kochou Shinobu, who was nearby, heard Cheng Mo suddenly say he was leaving, and a trace of imperceptible surprise and complex emotion flashed in her violet eyes.
She gently tucked a wisp of hair behind her ear, not speaking immediately.
Cheng Mo looked at Tanjirou and explained: "I taught you the Breathing Technique out of urgency before, but to truly learn the sword forms of Thunder Breathing, I still hope you get Teacher Kuwajima's personal approval and guidance. This is a sign of respect for the sect and its legacy."
Tanjirou's face immediately showed a look of understanding upon hearing this.
He quickly and solemnly nodded: "I understand, Teacher! This is as it should be!"
The boy always placed great importance on etiquette and tradition.
Kochou Shinobu also smiled and chimed in: "If it's Tanjiro-kun, there will definitely be no problem. Old Mr. Kuwajima will surely acknowledge you."
Her smile was still gentle, but the hint of complexity in the depths of her eyes had not completely faded.
"Thank you, Miss Kochou!"
Tanjirou happily thanked Kochou Shinobu, then handed her the pounded medicine.
"Then I'll go back and pack my things first! Teacher, Miss Kochou, I'll take my leave now."
He looked at Cheng Mo, then at Kochou Shinobu. His keen sense of smell seemed to detect that there was more to discuss here, so he wisely left first.
The pharmacy suddenly fell silent, leaving only the faint scent of medicine and the two of them.
After Tanjirou left, the smile on Kochou Shinobu's face receded slightly.
She looked at Cheng Mo, who hadn't moved, and her tone carried a hint of inquiry: "Teacher Cheng Mo, suddenly deciding to return to Peach Mountain, is there something else?"
Cheng Mo confirmed that there was no one else nearby before turning to Kochou Shinobu, his expression rarely serious.
He lowered his voice: "Shinobu, a demon from the Twelve Kizuki has made its way into this vicinity."
Kochou Shinobu's pupils constricted, and the last trace of a smile on her face vanished instantly.
Cheng Mo continued calmly, his voice low: "As expected. Even with Himura Senichi mostly delirious, and my energy suppression, I still couldn't completely cut off Muzan's perception."
"That guy is cunning, always hiding in the dark and observing. Because I'm here, it hasn't made any further moves." He paused, his tone carrying a hint of coldness, "There's no sense in defending against a thief for a thousand days; it's too passive. We need to find a way to lure it out and kill it."
Kochou Shinobu's heart tightened, and her fingers subconsciously clutched the edge of the paper bag holding the herbs, making a faint rustling sound.
A Twelve Kizuki demon infiltrating the vicinity?
This news was like a splash of ice water, instantly making her realize the seriousness of the situation.
This directly concerned the survival of the Butterfly Mansion.
All the injured, medical staff, precious medical achievements... especially the Himura father and daughter, faced immense threat.
She immediately cast aside all distractions, her delicate brows furrowed.
Kochou Shinobu's expression became extremely serious, and she quickly whispered, pressing for details: "Are you sure it's a Twelve Kizuki? Roughly where is it? What should we do?"
Her speaking speed increased, clearly having entered a state of high alert, ready to immediately discuss countermeasures with Cheng Mo.