Isekai Mizuki S1 - A World With Demons

Chapter 123 - A Sudden Fight

Everyone turns behind them, and they can see Muzan step forward, emerging from the darkness. "Ready to die?" he asks rhetorically, clapping his hands. Akaza's domain starts to shake, and everything starts getting pushed upward.

"SHIT, WE'RE GONNA DIE!" Murata yells, fearing for his life. "NOT YET!" Nezuko replies, quickly transforming into a giant to protect them from imminent death. With her titanic body, she knelt over and covered all of her classmates.

Outside the domain...

Gyomei and Giyu had just taken down the ice creature, and fell into despair, knowing that their efforts to kill Akaza were in vain. They returned to where the students had fallen, and just before they reached that spot, the ground exploded, launching 18 people out plus a gigantic Nezuko, and Muzan, who had just hopped out.

"WAIT, THAT'S..." Giyu realizes, gripping his sword. Gyomei threw his flail forward, busting open Muzan's head. "MUZAN KIBUTSUJI!" Giyu finishes, freaking out. Unfortunately for the Slayers, Muzan regenerated his head. "Damn, Mizuki was right. No matter how many times you decapitate Kibutsuji... he will not die!"

The two Hashira contacted the other teachers in Kimetsu Academy who were also affiliated with the Slayers Corporation. Mitsuri, Obanai, and Sanemi replied, stating that they were heading towards the scene and that they would arrive as soon as possible.

All the students of Class 2-A crashed onto the grass and regained their surroundings. They realize that they're looking at Muzan Kibutsuji, and the Water Magic users heal everyone before proceeding to fight Muzan. "CHAAAAAARGE!" Isekai yells, prompting everyone to rush forward.

A huge fight starts, and everyone tries to fight Muzan with all they have. No one hesitated for a second, and everyone cooperated with one another to consecutively perform two or three-person techniques. "Ah, I recognize you all! You're the people I fought with at that carnival! You've clearly improved, but that won't stop me! YOU'LL ALL BE DYING TONIGHT, MOTHERFUCKERS! PREPARE FOR YOUR END!" Muzan yelled.

He started deploying his techniques, using Flesh Whips that come from his arms, thighs, and spine. Everyone was struggling to keep themselves alive. They fought tooth and nail so that they could stay alive.

"Damn it, damn it, damn it...!" Kanao cursed, leaping back three times to avoid a flaming ball attack from Muzan. "He's too strong...! I doubt he's even trying...!"  she thought, cutting off the whips that were headed towards her. "Come on, step it up a little, won't you?! I can literally DANCE while fighting you deviants!" Muzan commented in a disappointed tone as he launched a large flame ball that was aimed at the slayers. They tried to push it back, and they did so, deflecting the attack by sending it to the sky. At that moment, Kanao remembered something.

-=FLASHBACK=-

Demon Retribution Front Main Headquarters, 9:30 AM, July 6th, 2030

Kanao was called into Tamayo's lab. She had been making her way there, and she was just buttoning up her uniform. Tanjiro was passing by, and he waved to her, and she waved back. When Kanao arrived, she knocked on the door, and one of Tamayo's assistants opened it.

Tamayo noticed her, and Kanao walked over. "Can I entrust you with something?" she requests. Kanao asks what it is. "This is a drug I made specifically to use against Kibutsuji. I put the transformation reversion cure into it, but, on the off-chance it doesn't work, I threw a few more things into the mix. I put my cerebral fluid so I could annoy him and talk to him while you fight, should this ever be injected into him, along with a few other drugs that could help you fight," she told her, passing the serum.

"If you encounter Kibutsuji, I want you to inject this into him. He'll only know about the human transformation drug, so in the event that you have to retreat, he WILL attempt to decompose the concoction, but he won't be able to touch the other things until he figures out what they are," she continued, finishing her sentence. Kanao nodded and placed the serum in her skirt pocket.

-=FLASHBACK END=-

Kanao remembered about the serum, so she grabbed it and took the lid off. "ISEKAI!" she called, prompting him to look her way. "Take this! You know what to do!" Kanao yelled, throwing the serum at him. He catches it and nods. He runs towards Muzan at full speed, evading every attack that comes his way.

Isekai gets close to him, and stabs the serum into Muzan, injecting the fluid contents of the serum into his system. Unfortunately, Muzan grabs Isekai. Gyomei realizes this. "Mizuki!" he yells, rushing forward, when suddenly, a spine whip impales him, carries him through the air, and smashes him onto the ground.

"Mr. Himejima!" Masachika yelled, running towards him. Tanjiro tried to rescue Isekai, but he said otherwise. "RETREAT! IT'S NOT WORTH IT...! RUUUUUUUN!" he yelled. Everyone followed his command and ran away from the scene.

MizuTech Main Vessel, 4:01 AM

Everyone was in the infirmary, mourning Isekai's death. Genya and Murata went to check up on Gyomei. "I'm sorry, boys, but... he won't make it. We've tried everything we can, but... we can't patch up that wound. Himejima-san's gone past the point of being able to heal," the doctor told them, giving their condolences.

The heart monitor displayed a flat line. Gyomei Himejima was already dead, and the other Hashira were already mourning for him. Suddenly, Muzan appeared out of nowhere, and everyone drew out their weapons. "Relax, everyone! I'm not here to kill you. At least, not right now. I'm in a good mood right now, so I'll give you another chance," Muzan explained, placing Isekai down on one of the hospital beds.

"I busted your friend's metal arm and replaced it with a demon arm. It'll be able to regenerate, just like a demon's could. Mizuki Isekai isn't dead yet, I just put him into unconsciousness. Don't worry, he's not a demon either, except for his right arm. Anyway, to get straight to the point. I'm going to give you one last chance. I'll come back here at nighttime today. You'll have the whole morning and afternoon to prepare yourselves. Bye-bye," Muzan said, entering a door, then closing it, the door fading away after.

Isekai regained consciousness. "GAH! Guys, where am- wait, did you..." Isekai questioned. Tanjiro shook his head. "Kibutsuji delivered you here himself. He said he's gonna give us one last chance," he replied. Isekai took a minute to process the information. He then composed himself. "Then we use this morning to prepare for tonight. We need every resource we can get because we're all going to fight together. I surmise that Kibutsuji will send his forces from another side to attack us, so I'll spread units of Slayers on all sides of this building, but I'll leave one area for us to fight this bastard," Isekai said, giving his thoughts on the lineup.

"This is it, everyone. We won't fail again."

To be continued...