"Kairo Retsu… can you still hold on?"
In the rear chamber behind the arena, Tamayo was holding Kairo Retsu's arm, checking his condition with concern.
At the moment, Kairo Retsu had just undergone a blood transfusion with the blood that Sanemi Shinazugawa had released earlier. Now, his body was beginning to show signs of adverse reactions.
His breathing was labored, strange rashes had appeared on his skin, and his body was running a fever. He was pale, shivering… all classic symptoms of an incompatible blood type transfusion.
"Looks like I'm not the same blood type as Sanemi Shinazugawa… we're not a match for blood donations!" Kairo Retsu joked despite the discomfort.
"Kairo Retsu, your blood type is clearly incompatible with the Wind Hashira's. The rejection symptoms are severe," Tamayo said worriedly. "Are you really going to fight like this?"
As she spoke, Kagaya Ubuyashiki also watched the Hunter Guildmaster with concern.
"Hah!"
Kairo Retsu let out a laugh distorted by pain. He propped himself up using the wooden wall beside him, shoved Tamayo's hand aside, pulled out a Nullberry from his pouch, bit it in two bites, and swallowed.
"We Hunters… are goddamn Fanged Wyvern-type!" Kairo Retsu slung his Insect Glaive over his shoulder. "A medical emergency with just a few hours to live? Joke's on them—I never planned to live that long anyway! I'll just tank it!"
"I'm heading out!"
Without looking back, Kairo Retsu charged toward the battlefield, leaving Tamayo and Ubuyashiki behind, watching his figure in awe.
When Kairo Retsu emerged onto the platform above the arena, from where he could overlook the entire battlefield, he saw everyone giving it their all in the fight.
Across the ballista stations, regular Demon Slayer Corps members were scattered at various posts, firing arrows and triggering devices coated in Shinobu Kocho's poisoned blood, attacking Muzan as much as they could without interfering with the frontline swordsmen and hunters.
Joseph Joestar was now fighting in tandem with Naofumi Iwatani—one providing suppressive fire, the other using Naofumi's summoned shields as platforms to jump between, breaking down Muzan's cells with Ripple.
As for Kazuma—
He was still desperately eating.
"Haaah…"
Kairo Retsu took a deep breath as he looked at the sprawling battlefield, arms wide open, embracing this long, bitter night.
"Guildmaster, here's the item you requested, nya."
A Felyne appeared beside Kairo Retsu and handed him a glowing box.
"Thank you, kitty." Kairo Retsu patted the Felyne's head and tucked the luminous item into his chest. "This is my secret weapon… for Muzan."
"Alright then…"
Kairo Retsu chomped another Nullberry to ease his worsening condition, then sprang forward on his Insect Glaive:
"MUZAAAAAN!!"
"I'M FREAKING COMING FOR YOUUUUUU!!!!!"
He roared and leapt into the battlefield.
Above the arena, messenger crows circled, broadcasting the countdown until sunrise.
And that ticking clock gnawed at Muzan's mind.
If the sun rose while he was still trapped here, there would be nowhere to hide from its rays.
"NOOOOOO!!!!"
Muzan screamed.
"I WILL NOT DIE HERE!!!!"
"Fat chance!"
Kairo Retsu landed and instantly joined the fray.
"You won't even leave behind a single cell today!"
"Go, Bruce!"
As soon as he landed, Kairo Retsu marked Muzan with marking fluid, and his Kinsect took off.
"Sting him hard!"
He ordered the Kinsect:
"Sting his eyes, his nose, his ears—throw him off!"
Muzan couldn't comprehend what Kairo Retsu was shouting at the bizarre bug.
Just an insect? Did this fool really think a bug could be a threat?
A filthy, lowly creature?!
Muzan raised his whip-blade to swat it aside—
—but missed.
The next moment, the Kinsect dove straight into Muzan's face and bit down on his eyelid.
His vision was suddenly, massively obstructed.
"AAARGH!!!"
Muzan tried to swat it down in rage—but even at that range, he couldn't land a hit on what appeared to be an ordinary bug.
Then—chomp—another bite, this time on his ear.
"DAMNED FLY!! YOU—YOU DAMNABLE HUNTER!!!"
Muzan lost it, but there was nothing he could do against the Kinsect.
Joseph Joestar stared wide-eyed and gave Kairo Retsu a thumbs-up.
"Nice! So this was your trick?"
"Such a slimy tactic…"
Naofumi's mouth twitched slightly.
If someone used that on him, he'd definitely lose it.
"This is practical use of a Hunter's toolkit, kid!"
Kairo Retsu puffed out his chest proudly.
He prepped for the next phase.
"You all know about the Bait Plan, right?"
"You ready?" Joseph stepped back from the frontlines to join Kairo Retsu. He looked at Kairo's pale face.
"Are you sure you don't want to see if one of us has a more compatible blood type?"
"No time for that! Besides… riding monsters is what Insect Glaive users do!"
Kairo Retsu beamed and lifted his outer garment.
Attached underneath was a whole row of various-colored meat:
Paralysis Raw Meat, Poison Raw Meat, Sleep Raw Meat.
"Time to feed Muzan real good!"
Kairo Retsu grinned wickedly.
"I, the Hunter Guildmaster, will personally deliver the meal!"
"Let's go! Cover me!"
He and Joseph bumped fists and charged forward.
"On it!"
Joseph followed closely, his entire armor glowing as Ripple surged through him, breaking the bank on stamina just to clear the path for Kairo.
"Haven't had this much fun co-oping in ages!"
Naofumi smiled watching the pair move.
He swapped in Slicing Ammo—bullets that explode on contact and sever limbs—and aimed at Muzan's whip-blades.
"It's the Guildmaster!"
Tanjiro spotted Kairo Retsu entering the fray. He instantly called to his closest allies:
"Inosuke! Zenitsu! Kanao! Support the Guildmaster!"
"Ha! It's that helmet-wearing old dude from before!"
Inosuke raised his dual blades.
"We just need to get him to Muzan, right?!"
"Uwaaaaah! I'm going, I'm going!"
Zenitsu wailed as he scrambled to help.
Meanwhile, Muzan—watching Kairo Retsu being escorted toward him—
Suddenly… started to panic.
Just what the hell is this man planning by getting so close?!