Yoriichi Tsugikuni was gone.
He had promised to fight the scumbag boss together, but after finishing off his own brother, he had tearfully run off with him, leaving the main villain, Muzan, to them.
"Aaaah!" Nagi's train of thought was instantly broken by Genya's screams.
He saw Genya crying out in agony, several large trees sprouting from his body. The corrosive power of the Hashirama cells was simply too strong. His body was still developing and not yet strong enough to digest the cells, and he had used them in a hurry, leading to the current backlash.
The White Zetsu cells were relatively gentle, and Genya could digest them. But the Hashirama cells were exceptionally aggressive. One mountain cannot contain two tigers. Sensing the hodgepodge of miscellaneous demon cells in Genya's body, the two forces had declared war.
"Genya! Little brother, you can't die! Do you hear me?!" Sanemi Shinazugawa, at this moment, no longer had the composure of the Wind Hashira. There was only the worry of an older brother for his younger.
Genya's body flickered between a demonic state, a White Zetsu state, and sprouting branches and green leaves. After years of eating so many demons, the hidden dangers of indigestion had been accumulating. Now, in order to defeat Kokushibo, he had drunk the incredibly potent Hashirama cells, which had become the final straw that broke the camel's back.
"I'm sorry, brother. Back then... you killed our demonized mother to protect us, but I thought you were the murderer. I resented you for so long. All this time, I've felt guilty about what happened. Can you forgive me?" Genya asked, tears streaming down his face.
"What nonsense are you talking about? An older brother protecting his younger siblings, isn't that what he's supposed to do? What is there to blame? I never once resented you," the Wind Hashira, Sanemi, said, his own tears falling. "I didn't want you to join the Demon Slayer Corps because I just wanted you to get married, have children, and live a peaceful life as a normal person."
"That's right!" Suddenly, as if remembering something, Sanemi turned to Uchiha Nagi and pleaded desperately, "Please, save Genya! As long as you can save him, I'll do anything you ask! You can even take my life!"
Nagi frowned, examining Genya. "I consider myself Genya's teacher. I would save him even if you didn't ask. But his problem now is that he has ingested too many demon cells in the past, and the hidden dangers that have accumulated over the years have all erupted at once. This is tricky."
"Genya, your body right now is a battlefield. All sorts of miscellaneous demon cells have joined together to fight the Hashirama cells. They are all eroding each other, using your body as their arena. If this continues, you will surely die."
"Is there still a glimmer of hope?" Sanemi looked at Nagi expectantly.
Nagi nodded. "There is. I'll inject another tube of Hashirama cells into you, to give them the overwhelming advantage to defeat those miscellaneous demon cells. Then, after it wins, I'll inject you with another type of cell to maintain the balance. Whether you can survive... that will be up to you."
Half of Genya's body had already turned into branches, while the other half was demonized. He smiled. "Nagi-sensei, let's do it. If I die, it's my fate."
Nagi took the previous test tube #2 and injected the Hashirama cells directly into Genya's vein. His body immediately underwent a massive change. The treelike part of his body began to overwhelm the demonized side. The various demon cells that had remained in his body from years of consumption were all eroded and devoured by the Hashirama cells.
Just as his entire body was about to turn into a great tree, with only his head remaining, Nagi took out a tube of blood and injected it into his neck.
It was the cells of the Uchiha clan.
After doing all this, Nagi sighed and created a shadow clone to watch over Genya. "I'm going to find Muzan. Your injuries are too severe; stay here and rest for a while. Especially you, Genya, your injuries are worse than Muichiro's. Muichiro-kun, you watch over these two. There are still many demons with the strength of the Lower Ranks in Muzan's stronghold. Don't let them harm these two."
Muichiro's severed arm and pierced chest seemed like severe injuries, but compared to the Shinazugawa brothers, he was the least injured. Nagi had already reattached his arm, but it was still unable to be used in battle for now.
"Alright. Are you sure you don't need us to help you fight Muzan?"
Nagi smiled. "Muzan is but a grain of sand. He cannot win."
With that, he vanished with a Body Flicker. Nagi began to search for Nakime's presence. To fight in the Infinity Castle, killing Nakime was the top priority.
"Oh, my... Upper-Rank One, Lord Kokushibo, is he really dead, just like that?"
In a hall decorated like a religious sanctuary, lay the bodies of more than a dozen beautiful young women. In the middle of them, a handsome man with rainbow-colored eyes, with the character for "Two" carved into them, was feasting.
This was Upper-Rank Two, Doma. He was the one of all the Upper Ranks who had best maintained his human form. Standing in a crowd, he was completely indistinguishable from a human.
Doma had been born with rainbow-colored pupils. His parents believed he was the reincarnation of a god, that a human surname was unworthy of him, so they had not given him one. As he grew up, he was worshipped as a god by the ignorant villagers, and eventually founded the Paradise Faith, with himself as the leader.
However, despite his cheerful personality, Doma was born without emotions. Yet, day after day, he listened to the prayers of his followers, to their various negative emotions. A person like this would either achieve enlightenment one day and become a saint, or become a demon. Unfortunately, no enlightened monk came to guide him. Instead, Muzan came. And so, Doma naturally became a demon.
After becoming a demon, Doma's strength grew without any apparent bottleneck, until he reached the rank of Upper-Rank Two. If not for his playful nature, if he didn't hide his true strength, he might not have necessarily lost in a fight against Kokushibo.
"Wipe that fake look off your face. You don't have a single shred of grief in you. You have no emotions at all."
A beautiful figure was staring coldly at Doma. It was Shinobu Kocho. She had finally found the murderer of her older sister, the long-sought Upper-Rank Two.
"Don't say that. We've known each other for hundreds of years. The depth of our feelings is not something you humans can imagine. Sob, sob..." Doma held a fan in one hand and a handkerchief in the other, wiping away his tears. However, no matter how expressive his face was, it could not hide his eyes. There was not a single trace of human emotion within them.
"You remember this haori, don't you? It was my sister's," Shinobu said, her face dark as she pointed to the clothes she was wearing.
Doma frowned in thought for a moment. Suddenly, he plunged his sharp fingers into his own brain and stirred it around. A look of realization dawned on his face. "Oh, oh! I remember now! That pretty older sister! What a pity. Such a powerful Hashira, and such a beautiful young woman. It's a real tragedy she couldn't achieve eternal life within my body."
"Your strength is not bad either. To have trained your body to such a degree, you must be a Hashira, right? You must have your troubles. How about you join the Paradise Faith? Let me lead you to eternal life, and you will no longer have the worries of a human."
Shinobu sneered, pointing her sword at the female followers he had eaten on the ground. "Eternal life? To achieve eternal life by being eaten by you?"
Doma replied with a perfectly straight face, "That's right. They have all entered my body, become one with me, and thus achieved eternal life. All the suffering of the human world is gone for them. Look how happy they were before they died."
Shinobu suddenly broke into a smile. "Alright..."
"Really?"
Clang!
Elsewhere in the Infinity Castle, the Serpent Hashira, Obanai, and the Love Hashira, Mitsuri, were fighting the castle's steward, Nakime.
Every time Nakime plucked her biwa, the gravity would shift. But the loss of their center of gravity didn't stop them. What was difficult was her ability to control everything here at will. Doors would fly out from time to time, blocking their advance and attacks, or a few demons would be teleported in. It was incredibly annoying.
The wooden doors, the floors, even the entire room—everything in the Infinity Castle seemed to be under Nakime's complete control. She could move anything she wanted. The room she was in was constantly moving through the complex environment, not only making it difficult to pinpoint her location but also allowing her to teleport anyone who attacked her to another place.
If Muzan wasn't intent on wiping out the entire Demon Slayer Corps, if she just teleported one Hashira at a time to the Upper Ranks to be killed, while the others were left to play hide-and-seek in the Infinity Castle, the Demon Slayer Corps would have been annihilated long ago.
"Shuriken Shadow Clone Jutsu!"
A single shuriken flying towards Nakime quickly multiplied into a thousand, raining down on her like a metal storm from a Gatling gun. Nakime was terrified. She plucked her biwa several more times, reversing the gravity and shifting the room, and finally managed to block the ranged attack.
"Nagi-san!"
"That's great!"
The Hashira of the Demon Slayer Corps, while strong, lacked ranged attacks. This was a major disadvantage, and they could only grit their teeth and glare hatefully at Nakime. Nagi's arrival gave the Love Hashira and the Serpent Hashira hope.
"Leave her to me. I'll finish her in three moves. You go support the others."
"Th-three moves?" The Love Hashira, Mitsuri Kanroji, had a look of pure adoration on her face. Nagi-san is so cool!
Beside her, the Serpent Hashira, Obanai Iguro, looked at Nagi with a dark expression, a pang of jealousy rising in his heart. He had liked the Love Hashira for a long time.
Shadow Clone Jutsu. Nagi split into ten clones, and each clone threw a kunai at Nakime.
Nakime plucked her biwa, and a wooden door descended from the sky, blocking the kunai.
However, after a series of collisions, the kunai changed direction and flew straight towards Nakime from behind. Nakime plucked her biwa again, and the room she was in instantly changed its position.
However, one kunai had lodged itself in the ceiling above her.
Flying Thunder God Jutsu!
Nagi instantly appeared above Nakime. She sensed him and looked up in shock, only to see a pair of red eyes. Nagi also saw Nakime's face. She was a woman of infinite charm in terms of her aura and appearance, but her face had only a single, bowl-sized eye, which was truly a terrifying sight.
At this moment, the image of the Sharingan appeared in Nakime's eye. She was now under the control of Nagi's Mangekyo.
If even Yushiro could control Nakime with his Blood Demon Art, it was no surprise that Nagi's Mangekyo could do the same.
"Hmph. From now on, the Infinity Castle is under my control. Scumbag boss, just you wait to die," Nagi sneered. "Teleport the Serpent Hashira, the Love Hashira, and the Stone Hashira to Tanjiro's location."
Poor Akaza was about to face a five-on-one fight.