Under absolute power, even the vaunted regeneration of the Upper Rank demons lost all meaning.
Before he had the chance to regenerate, Akaza was crushed to pieces in Yohan's hand.
"It's over."
Yohan looked calmly at the spot where Akaza had completely disintegrated.
He knew—the day of the final showdown with Muzan Kibutsuji was fast approaching.
All that remained was for the research to succeed.
[Ding!]
[Random Quest: Mugen Train (Completed)]
[Reward: Berserker's Roar (Removes skill startup delay)]
"Skill startup delay? System, are you saying my Taunt skill is now instant-cast?"
[Yes, Host.]
Back in the early stages, Yohan had found the Taunt skill somewhat useful. But as his power rapidly soared, there was no longer any real need to force enemies to attack him—most of them couldn't even withstand his strikes.
But now that Taunt was instant-cast, it gave Yohan much more confidence in dealing with Muzan.
He was well aware of how slippery that monster was.
Back then, Muzan had managed to evade Yoriichi Tsugikuni until the man's dying breath. If their current bait strategy failed to finish him off completely, there was a real risk Muzan would disappear without a trace again.
Yohan had no interest in playing cat-and-mouse with a rat like that.
"Yohan!"
Mitsuri Kanroji and Kyojuro Rengoku finally arrived, both gripping their Nichirin swords as they rushed to Yohan's side with wary expressions.
"Yohan, where's Akaza?"
"What's the situation here?"
Rengoku had come straight from defeating Lower Rank One, Enmu, and had rushed over with Mitsuri. Though he knew Yohan had previously slain Upper Rank Two Doma, he didn't dare underestimate any of the Upper Ranks.
"He's gone. Dead."
"Gone?!"
Slain already?
It wasn't that Rengoku didn't believe him—he just found it almost absurd. It hadn't even been that long since he'd fought Enmu himself.
He and Mitsuri had needed time and effort just to take down a Lower Rank. And yet Yohan had already finished off an Upper Rank… and not just any, but Upper Rank Three Akaza?
"You've become… that powerful?"
Rengoku blurted it out without thinking. Yohan's strength was starting to defy comprehension.
"Haha, not really. We actually chatted for a bit at first."
Yohan didn't think he'd been especially fast. After all, Demon Bound Armor now carried the power of a dragon.
In the end, Demon Slayer demons were merely troublesome due to their regeneration and the limited ways to kill them.
But raw power? That changed everything.
What Yohan was truly thinking about now was his peaceful life after killing Muzan.
"Waaah! Yohan, I didn't even get to fight beside you!!"
Mitsuri pouted, a little upset. She wasn't unhappy that Yohan had slain Akaza—on the contrary, she agreed that demons should be dealt with swiftly.
But everything had ended so quickly. All that training and effort she'd put in felt almost pointless. She could've just stayed back at Butterfly Mansion refining new recipes.
"Hahaha, but Mitsuri, think about it—because I finished fast, I get to spend more time with you."
Seeing her expression, Yohan realized Mitsuri really had a strong desire to fight side by side with him.
Had he known earlier, he might've let Akaza live just a little longer.
"Mm, Mitsuri, Yohan is right," Rengoku added. "When facing demons, we must strike them down at once."
Unlike Yohan and Mitsuri, who were relatively new to the battlefield, Rengoku had fought on the front lines for a long time. He had seen too many tragedies caused by arriving too late.
"Mmm… that's true."
With a little nod, Mitsuri came around. Being with Yohan was definitely more important. With a cheerful smile, she clung to him again.
"Well, now that it's over, let's head back to Butterfly Mansion. What about you, Kyojuro?"
Yohan had gotten used to staying at Butterfly Mansion. All his running around before had been due to not being strong enough.
"I won't be returning just yet. I still have to check on the train and patrol my Flame Hashira region."
Compared to Yohan, Kyojuro clearly had far more responsibilities.
"Alright then. See you next time."
"Haha, of course!"
Rengoku turned and dashed off toward the train. There was no need for many words between comrades.
"Two more dead!"
"Useless. All of them—useless."
When Akaza and Enmu—both filled with Muzan's blood—died, the Demon King immediately sensed it.
He had already flown into a rage over Doma's death, and now this.
An Upper Rank demon, slain by humans? That hadn't happened in centuries.
Even when Upper Ranks were replaced, it was through internal struggle and devouring. But Doma—Upper Rank Two—had simply died. What's worse, he'd died to sunlight.
Humiliation.
That disgraceful image had been the last thing Muzan saw of Doma's final moments.
Since then, his patience with the Upper Ranks had worn thin.
And now, Akaza had gone to battle willingly—alongside a Lower Rank he'd just generously infused with blood—and within days, they were both gone.
"…Nakime. Summon the remaining Upper Ranks. Now."
"Yes, Lord Muzan."
Nakime didn't hesitate. As someone constantly near Muzan, she knew that even a stray thought could mean death.
The summons did not take long.
Infinity Castle.
Silence.
Only four Upper Rank demons remained, all kneeling before Muzan Kibutsuji.
They could feel it clearly: the raging fury rolling off their master.
"Can anyone explain to me," Muzan's voice thundered, "how the Upper Ranks—my Upper Ranks—have started dying to humans?"
"Doma's death was mere days ago. And now Akaza has followed him."
"Did I raise you all just so you could die when it's convenient!?"
His roar echoed through the stone halls.
None of the four dared respond. A single word could cost them their lives.
Looking at the four trembling figures kneeling before him, Muzan's expression grew colder.
"Don't think that keeping silent will spare you."
"If none of you have a solution, I might as well treat the Upper Ranks like I did the Lower Ranks."
A collective shudder ran through the demons.
They knew what had happened to the Lower Ranks.
Not long ago, after yet another Lower Rank had been slain by the Demon Slayers, Muzan had declared himself done with them.
He slaughtered every single one—except for Lower Rank One.
"Lord Muzan!" Upper Rank Five Gyokko finally dared to speak.
Thud!
His head dropped to the floor.
"Shut up, you pathetic trash."
Muzan didn't want excuses. He wanted blood. He wanted vengeance.
Gyokko, now headless, didn't dare utter another word. He knew—if he spoke again, it might be the end of him.
"Lord Muzan," came a new voice, calm and confident.
"I may have someone you'll be very interested in…"