Time flies by, and almost three months have passed. Zenitsu's strength has greatly improved, and he has developed his own style.
"It's time to go back. I wonder if Miss Shinobu listened to me," Lixing thought, lying on a peach tree, feeling gratified by Zenitsu's hard work over the past three months.
"Zenitsu, get ready. We're returning to the Demon Slayer Corps tonight. I have a feeling a great battle is about to begin."
"Oss!" Zenitsu was extremely excited, finally ending this painful training.
That night, Lixing and Zenitsu left Peach Mountain without even having dinner.
"Grandpa, we're leaving now. You must wait for me to return!" Although he wanted to end his training, Zenitsu was still reluctant to leave.
Kuonji Jigoro's eyes were filled with relief. Zenitsu had reached the pinnacle. He turned his back to Zenitsu, saying, "I will wait for your return. May your battles be prosperous!"
...
Meanwhile, in the Infinity Castle, a clone of Nakime had already located the headquarters of the Demon Slayer Corps.
"Muzan-sama, the headquarters of the Demon Slayer Corps has been found. Will you go there personally?"
Muzan, holding a map and directing Nakime, was incredibly excited. "Nakime, your growth is far beyond my expectations. It's wonderful! I will find Nezuko soon!"
...
By the time Sanemi Shinazugawa had crushed Nakime's clone, Lixing and Zenitsu had already returned to the Demon Slayer Corps headquarters. Lixing had carried Zenitsu all the way back. Upon arrival, they headed straight for the Butterfly Mansion. After leaving Zenitsu there, Lixing went to find Shinobu.
In a small hut near the Butterfly Mansion, Lixing found Shinobu, along with Tamayo and Yushiro.
"Li Yun, scan Shinobu's bodily data."
Lixing had no time for greetings. He first needed to check the extent of the wisteria poison in Shinobu's body. Li Yun immediately used Lixing's eyes to scan Shinobu.
"Xingxing, the wisteria poison currently occupies sixty percent of Shinobu's body. It seems it has been incubating for over two months."
Lixing sighed inwardly. He hadn't expected it to come to this. He had to confine Shinobu. Lixing had to take drastic measures; otherwise, if they separated in the Infinity Castle, Shinobu would still end up as in the original storyline.
"It's been a long time, Mr. Lixing. Miss Kocho's condition is something she brought upon herself. I haven't broken our agreement," Tamayo said, seeing Lixing's unwavering gaze on Shinobu, and explained Shinobu's situation.
Although Yushiro disliked Lixing, he offered a greeting as well, given that Lixing had previously granted them the ability to walk in sunlight.
Lixing ignored Tamayo and Yushiro and walked up to Shinobu. "Miss Shinobu, you are a true genius. To have achieved this, I admire you."
Shinobu felt a pang of guilt. Lixing had warned her many times, yet she hadn't listened. She could only change the subject.
"Lixing-kun, I have researched a suitable treatment drug based on your blood and have distributed it to the members below."
"I'm sorry. Even if you hate me, I have to confine you. I'll release you after I find Douma," Lixing apologized inwardly to Shinobu and placed a hand on her shoulder.
"Blood Demon Art, Infinite Domain!"
Shinobu instantly fell into a small hut, far from where Daki was. Lixing was not worried that Shinobu would be able to find them.
"Lixing-kun? Where is this? Let me out quickly!" Shinobu looked around and, finding no sign of Lixing, could only shout at the sky.
After shouting for a long time with no response, Shinobu could no longer hold back her tears. Why wouldn't they let her avenge her sister!
"Is this what you meant last time by confining me?"
...
"Mr. Lixing? Was that a Blood Demon Art?" Tamayo covered her mouth, her eyes filled with disbelief. Humans could use Blood Demon Arts.
Lixing remained silent and looked at Tamayo. "Hand it over. The medicine you prepared. Let me send it into Muzan Kibutsuji's body."
"How did you know?" Tamayo found this man increasingly unfathomable, as if he knew everything.
"Do not be disrespectful to Lady Tamayo!" Yushiro, seeing Lixing reach out to take Tamayo's centuries of research results, immediately stepped in front of Lixing.
"Yushiro, your Lady Tamayo wants to use her own body to be absorbed by Muzan Kibutsuji, thereby injecting him with the drug that turns humans into demons. Are you sure you want to stop me?"
Yushiro was shocked and turned to Tamayo. "Lady Tamayo! Is this true?"
Tamayo slowly lowered her head. "Yushiro, I'm sorry. I lied to you for so long."
Lixing couldn't stand their incessant mawkishness. He knocked Yushiro unconscious with a single blow and grabbed Tamayo's hand.
"Forgive me, Miss Tamayo."
He then bit Tamayo's arm and began to suck vigorously. If possible, Lixing did not want to absorb the medicine from Tamayo this way, but Lixing had not yet mastered other methods. Transferring the medicine out was simple; all it would take was a cut and it would spread through the blood.
After a while, the medicine in Tamayo's body was completely absorbed by Lixing. Tamayo, having lost too much blood, collapsed on the ground at that moment.
"With me here, I will not allow anyone to die. This is my responsibility since coming to this world, or at least that's what I believe. Wake up Yushiro. Prepare for battle." With that, Lixing left, adding mentally, excluding any random strangers.
...
"I never imagined you would listen to me tell you so much. Thank you, Muzan!"
As soon as Lixing arrived at the Ubuyashiki residence, he heard Kagaya Ubuyashiki's words. He was preparing for self-destruction.
"Blood Demon Art, Infinite Domain!"
At this point, Lixing could no longer afford to hide his abilities. The plot would end after this battle anyway. Lixing could only, in an instant, place Kagaya Ubuyashiki and Lady Amane into the Infinite Domain, along with Kagaya's two daughters.
Shinobu, who was kneeling on the ground and crying, suddenly saw four people descend from the sky. Their eyes met.
"Master? Lady Amane?"
"Shinobu?"
...
Boom!
A deafening explosion erupted at the Ubuyashiki residence. All the Demon Slayers rushed towards the scene.
Muzan Kibutsuji's body was blown away by half. Lixing was also caught in the blast, his body similarly mangled as Muzan's.
"Was that a Blood Demon Art? Why did you save the Ubuyashiki family? Who exactly are you?" Muzan glared fiercely at Lixing. At this moment, the heavily injured Lixing was likely unrecognizable even to his mother, let alone Muzan.
"Muzan Kibutsuji, pleased to meet you. You've already annoyed me immensely." Lixing and Muzan's bodies were rapidly regenerating, and both were restored to their original forms almost instantly.
Muzan immediately recognized this man as the one who wielded the Sun Breathing.
"It's you!"
Lixing wasted no words, appearing behind Muzan in an instant. He plunged a hand in, furiously infusing the medicine researched by Tamayo, along with a trace of his own blood.
Muzan immediately felt his body changing and jumped backward.
"What did you do to me?"
Seeing that the medicine had been delivered, Lixing's plan was complete. The next step was to enter the Infinity Castle for the final battle. He drew his Nichirin Blade and slashed at Muzan.
"Sun Breathing, First Form, Clear Blue Sky!"
After centuries of torment, coupled with the medicine injected by Lixing, Muzan's body was in extreme discomfort. He had no choice but to drag the entire Demon Slayer Corps into the Infinity Castle. He needed to find a place to hide and suppress what was inside him.
"Muzan Kibutsuji!!" Tanjiro and the Hashira arrived at the Ubuyashiki residence. Seeing their enemy, they roared in fury and drew their Nichirin Blades, ready to strike.
The Hashira, enraged by the death of their Master, also charged towards Muzan.
Suddenly, squares appeared beneath everyone's feet. The ground below transformed into individual rooms, and all the members of the Demon Slayer Corps fell into the Infinity Castle.