"AAAAAGGHHHHHH!!!!!!"
Muzan's roar echoed through the very heart of Infinity Castle.
At the same time, the others scattered throughout the castle began to notice something unusual.
Several Demon Slayer Corps members locked in combat with demons suddenly realized:
The demons were withdrawing. It was as if something had spurred them—driven them—to rush in the same direction.
Infinity Castle itself began to shift more frequently—
It seemed even Nakime, the one controlling the castle, was affected by something.
"All the demons inside Infinity Castle are heading in the same direction?"
The young Master, who was monitoring the situation through messenger crows, instantly caught on to the trend.
Inside Infinity Castle, the only one capable of orchestrating something like this…
Was Muzan Kibutsuji.
The young Master immediately relayed this intel to his father, Joseph, and Kazuma.
"This Muzan guy is such a coward!!!!" Kazuma shouted while chugging a potion.
"He just started fighting Iwatani, and he's already freaking out?!"
"You can't judge these inhuman beings with human morals, even if they once were human."
Joseph, who had witnessed people close to him become vampires, replied calmly.
"But I doubt Muzan's calling those demons to protect him."
"After all, neither Kokushibo nor Nakime went to help him, right? Those lesser demons…"
Joseph narrowed his eyes.
"He's probably calling them to use as food!"
While Joseph pieced this together, Ubuyashiki came to the same conclusion.
He began directing the Demon Slayer Corps to form up and intercept the demons advancing toward Muzan.
The young Master relayed orders via messenger crows to block as many of the advancing demons as possible.
The goal:
To eliminate as much of Muzan's remaining fighting strength before he could fully recover.
—
Meanwhile, Kokushibo was locked in a brutal battle against four Hashira… and Kairo Retsu.
After Kairo's blade briefly shimmered with white light, his fighting style suddenly changed.
No longer just rolling around on the ground, he now fought with broad, sweeping motions.
His moves appeared full of openings—yet Kokushibo couldn't determine what attacking him would really do.
Kairo was like a flypaper trap coated in glue: once you attacked him, he'd entangle you by any means necessary—
Leaving you open for the other demon hunters to strike at your neck.
Even stabbing him through or hacking off limbs didn't work.
The moment he screamed "Ow! That hurts!"—he was already counterattacking.
What's more…
Muzan's cells inside Kokushibo's body were now screaming at him.
Kokushibo! How many Hashira have you killed already!?
Kill them all! Go kill Ubuyashiki!
Once you've taken out the Demon Slayer Corps—get over here!! Kill this freak hunter who fell out of the damn sky!!!!!!
Muzan's voice dripped with rage.
The words made Kokushibo realize that Kairo had other allies—and that those allies were already threatening Muzan.
"…You've got a weird look on your face."
After taking a direct hit, Kairo returned one of his own while keeping constant eye contact with Kokushibo.
"Let me guess! It's Muzan, right?!"
As he slashed, Kairo continued:
"Don't tell me he's calling you for backup? Ha! Of course—Muzan's just that much of a coward!"
"!"
Kokushibo's pupils dilated.
He hadn't expected Kairo to read his thoughts so precisely.
"How do you know that?!"
Kokushibo forced the four Hashira back and demanded:
"You… You planned this all from the beginning?!"
"That's right! Everything is going exactly as we planned!!"
Kairo flashed a dazzling grin.
"Right now, all the Upper Rank strength in Infinity Castle—either dead or tied up. There's no one left to help Muzan out of this mess!"
"We hunters! Sure, we don't have Nichirin Blades that can kill you—but…"
Kairo's eyes locked onto Kokushibo.
"You think my companions… are as weak at fighting as I am?"
"I'm the weakest hunter of us all!"
Kairo declared with bizarre pride.
"Only the weakest hunter gets to fire the Signal Flare…"
"And summon three NPCs with terrible movement AI!"
"What nonsense are you spouting?!"
All six of Kokushibo's eyes opened wide in fury.
"You—an abnormality—how many of you are there?!"
"How many of you have driven Lord Muzan to this point?!"
He was already weighing whether to break away and head for Muzan's location.
"Just one, of course. The strongest one among us."
Kairo never took his eyes off Kokushibo's expression, continuing his provocation.
"And that guy's got a lot of pent-up rage from his past."
"Wouldn't you say it's a good chance to let him vent a little?"
—
"HA HA HA HA HA!!!"
At this very moment, Naofumi Iwatani was gripping his Heavy Bowgun with both hands, unleashing devastating barrages at Muzan without pause.
The frustration and fury he'd accumulated in his own world—
All of it evaporated now in the booming thunder of cannon fire.
"Looks like I'm never gonna unlock that 'Rage Shield' now!"
Naofumi shouted with uncontained excitement.
"YOU DAMN—WRETCHED—CREATURE!!!!"
Muzan howled as the cannon barrage relentlessly bombarded him.
His flesh—normally capable of astonishing regeneration—
Was continuously shattered and rebuilt, over and over, driving the dungeon master into humiliating fury.
He couldn't understand.
How had things ended up like this?
He knew the power of guns and cannons.
He'd experienced them before. They never posed a real threat.
But this man—
Black-haired, a shield on his arm—
The gigantic weapon in his hands kept firing ceaselessly, unleashing shell after shell of devastating artillery.
None of it was sunlight-based. Muzan could not be killed by it.
But every time he tried to flee—
Another shield materialized in front of him.
Then came another wave of bombardment, blowing his body apart once more.
"Hell, maybe…"
Naofumi's grin grew broader as he gazed at Muzan's miserable expression—
"Maybe I should rename myself: the Hero of the Cannon!"