Tanjiro and the others could only watch as the white-furred werewolf completely overwhelmed Muzan, blasting him away with terrifying force.
Obanai swallowed. "He's… strong."
Mitsuri stared wide-eyed. "D–Did he do it? Is Muzan dead?"
Giyu shook his head, eyes never leaving the distant impact zone. "I don't know. But I don't think Muzan can be killed without a Nichirin blade… or sunlight."
Then Giyu turned slightly toward Tanjiro. "You said you knew about this 'werewolf' thing, didn't you? Can Akira even turn back into a human?"
While Akira had been fighting Muzan, Tanjiro had already explained to them everything Akira had told him about werewolves. Right now, he was their only source of information.
Tanjiro swallowed and answered honestly. "Akira-san told me… someone who turns into a werewolf will return to being human at sunrise."
Obanai clicked his tongue. "Great. So we have to deal with two monsters until sunrise."
Then Mitsuri's voice trembled. "U-Um… look."
They all followed her gaze.
The werewolf slowly turned.
Glowing purple eyes locked onto them.
A killing intent so dense it felt physical slammed into their bodies, freezing them in place.
Mitsuri's voice wavered. "T-That's… scary…"
They had all seen it. The way Akira had completely overpowered Muzan.
Could they really fight something like that?
Obanai spoke through clenched teeth. "Running is impossible. He'll catch us instantly."
"The best we can do," he continued, "is buy time until reinforcements arrive."
Giyu nodded once, gripping his sword tighter.
"Yes. That's the only option we have now."
Just then, Akira rushed toward them.
He was impossibly fast.
"He's coming!" Tanjiro shouted.
In the same instant, all of them activated their Demon Slayer Marks. They knew it instinctively; without them, they wouldn't survive even a single exchange.
The werewolf lunged.
They moved together.
"Water Breathing—Eleventh Form: Dead Calm!"
"Serpent Breathing—Fourth Form: Twin-Headed Reptile!"
"Love Breathing—Second Form: Love Pangs!"
"Hinokami Kagura—Burning Bones, Summer Sun!"
Their attacks collided with Akira's body all at once.
But they couldn't cut through him.
His white fur resisted their blades, and even the shallow wounds that did appear healed instantly before their eyes.
Akira roared and swung both claws in a wide arc, blasting them all back with sheer force.
Then he turned on Tanjiro.
Tanjiro barely raised his sword in time.
The clash rang out like a bell being struck.
But instead of resistance, pain exploded through his arms. The impact hurled him backward, his feet carving deep trenches into the floor before he finally crashed into a pillar.
"Tanjiro!" Mitsuri cried out, rushing in to intercept with her whip-like Nichirin blade.
Akira backhanded her without even turning properly.
She was sent flying.
Giyu and Obanai flanked him from both sides, striking at the same time.
Akira didn't even bother blocking.
Their blades landed, but they barely did any damage.
Nichirin blades worked on demons. They might even work on vampires.
But werewolves didn't burn in sunlight.
So against him, they were far less effective.
Akira roared and released a sonic wave.
The shockwave wasn't as strong as the one he'd unleashed against Muzan, but it was still devastating.
Both of them were blasted away.
The sound wasn't just loud. It was crushing.
Then he roared once more.
The shockwave hurled all four of them off their feet.
Obanai slammed into a wall, coughing up blood.
Tanjiro dropped to one knee, ears ringing, vision swimming.
Still… they stood back up.
Again.
And again.
Because if they didn't.
Someone would die.
Akira lunged again, claws flashing.
Giyu moved first, intercepting the strike and barely redirecting it. The impact numbed his arms, but it bought just enough space.
Tanjiro slipped in from the side, slashing at Akira's joints, trying desperately to slow him down, even by a fraction.
Mitsuri followed up, her whip-like Nichirin blade wrapping tightly around Akira's leg. She pulled with everything she had, trying to throw him off balance.
It didn't work.
Akira slammed his fist straight down.
The floor shattered.
The ground collapsed beneath them, and all of them fell together into the floor below. Before they could even regain their footing, Akira howled again.
The shockwave blasted outward.
All four of them were hurled in different directions, bodies smashing violently into the surrounding walls.
Tanjiro groaned and tried to push himself up.
Just as he felt something.
Akira was already there.
The werewolf lunged at him.
Tanjiro barely raised his sword in time, blocking with the flat of the blade as Akira snapped his jaws forward, fangs inches from his face. The force pinned him to the ground, claws digging into the stone beside his head.
He couldn't move.
And deep down, Tanjiro knows.
The only reason they had survived this long.
The only reason they were still alive.
It was because, somewhere deep inside, Akira subconsciously didn't want to kill them.
But his berserk state was spiralling further and further out of control.
And it wouldn't hold back forever.
Just as Tanjiro was about to be overpowered, a shout rang out from above.
"Akira, stop right there!"
Crimson ribbons snapped through the air.
They wrapped around Akira's arms, his torso, his legs, layer after layer, tightening instantly. The werewolf snarled, muscles bulging as he strained against the bindings. The ground beneath his feet cracked under the pressure.
Erika landed in front of him, boots skidding backward as she fought to hold her ground.
"Calm down, Akira!" she shouted, her ribbons wrapped tightly around him, holding him in place.
Erika had finally arrived.
The moment she first saw the werewolf, her body had frozen.
That form, those fangs, that presence dragged her straight back to the past. The memory of the werewolf attack when she and Akira were children surged forward. She had almost lost her life back then. Akira had almost died, too.
It was a trauma buried deep, one that still lingered in her instincts.
For a split second, fear locked her in place.
But then she saw Tanjiro.
She saw Akira about to kill him.
And she moved.
Because no matter what he looked like now, no matter how terrifying he had become.
It was still just Akira, so she was not too scared.
And she wouldn't let him hurt anyone.
So, she rushed forward and used her ribbons to tie him up.
For a brief moment, the bindings held.
Then the werewolf moved.
After a second of stunned stillness, Akira's muscles swelled violently as he began to tear against the restraints. The ribbons strained, screeching under the pressure.
Selena's voice rang out in Erika's mind.
"Erika-chan, don't bind him like that. He'll break them easily."
Erika realized it instantly.
She wasn't going to make the same mistake twice.
Before Akira could fully tear through them, she released the ribbons herself. The bindings unraveled just as Akira lunged at her.
Erika snapped her ribbons forward, weaving them into a dense shield in front of her. Akira's fist slammed into it, once, twice, again and again, each blow shaking her to the core.
"Erika-chan, don't let him bite you," Selena warned urgently. "Werewolf venom is deadly to vampires. It overwhelms their healing factor."
Yes. Werewolf bites were lethal to vampires.
That was why Muzan's regeneration had slowed so dramatically after being bitten.
Erika swallowed hard. "Then what do I do?"
"Lead him away from here," Selena answered immediately. "If he stays, more people will get hurt."
Erika nodded.
She turned her head toward the others and shouted, "I'll lead him away from here! Don't interfere!"
Then she spread her wings and launched herself into the air.
Crimson ribbons lashed out as she attacked Akira, not to wound him, but to provoke him, to keep his attention fixed on her.
"Akira! Look at me!" she shouted. "Just look at me, no one else!"
Before Akira could turn back toward the others, six crimson ribbons cracked through the air like whips. They struck his shoulders, his arms, the ground around him, loud, sharp, unmistakable.
"Akira!" she shouted again, circling him midair. "Look at me! Just look at me! No one else!"
The werewolf's head snapped upward.
Glowing purple eyes locked onto her.
Good.
She had his attention.
Akira roared and leapt, claws shredding the air where she had been a heartbeat earlier. Erika twisted mid-flight, gravity lightening her body as she flipped over him. Her ribbons snapped down again, wrapping around his wrist and yanking hard, pulling him off balance.
"Stay with me!" she yelled. "Don't look at anyone else, just look at me!"
Inside her mind, Selena's voice chimed in, far too cheerful for the situation.
"Wow. 'Just look at me and no one else'? That's straight out of a romance novel."
Erika nearly lost control of her flight.
"Is this really the time for that?!" she snapped back mentally, barely dodging another swipe that shattered the wall behind her.
Akira lunged again, faster this time.
Erika reacted instantly. Her ribbons wrapped around parts of his body, and she pulled upward with everything she had, forcing his momentum to follow her into the air. His focus stayed locked on her alone.
Everyone watching could only stare as Erika dragged him along.
Just like walking an unruly dog.
A dog that was actively trying to kill her.
Somewhere within the depths of the Infinity Castle, something crawled.
Muzan Kibutsuji's severed head skittered across the floor like a grotesque spider, thin tendrils of flesh acting as legs as it dragged itself forward. His regeneration was not functioning properly. It was slow. Painfully slow. Worse, his strength was draining away.
He was weakening.
He needed to eat.
To regain his power, he needed human flesh.
Driven by desperation, Muzan searched the corridors for prey, his senses locking onto an easy target. A fallen Demon Slayer lay motionless ahead, body already cold.
Muzan hurried forward and began to devour him.
Then he noticed something.
A small vial had fallen beside the corpse, glass, faintly glowing blue.
Muzan froze.
He remembered this.
Through his connection to all demons, he had seen fragments of what was happening across the battlefield. He had seen Demon Slayers drinking this mysterious liquid and their wounds healing at an abnormal speed.
"So that's it…"
His eyes narrowed.
"What would happen if I drank it?"
After a brief moment of consideration, Muzan consumed the liquid.
Instantly, he felt it.
His flesh twitched. His cells surged. Regeneration accelerated violently, far faster than moments before.
"This is… amazing," Muzan muttered.
His gaze shifted to the body beside him.
Another vial.
Without hesitation, he drank it as well.
His healing sped up even further. But that wasn't all.
Power flooded into him.
Strength.
Vitality.
Something more.
Muzan let out a low laugh that quickly grew into manic laughter.
"HAHAHAHAHA…"
His voice echoed through the castle's twisting corridors.
"Hoshino Akira… just you wait," he snarled. "I will make you suffer."
Erika dragged the werewolf away from the others, crimson ribbons snapping and retracting as she narrowly avoided his claws. Each swing split the air with terrifying force, tearing chunks from the castle walls as she twisted and climbed higher, keeping just out of reach.
Inside her mind, her voice trembled despite her focus.
"Selena, what next?How do we bring him back?"
There was a pause.
Then Selena answered, unusually hesitant.
"How am I supposed to know?I've never dealt with a situation like this before. I don't know how to turn a werewolf back into a human."
Erika's chest tightened.
"Did Akira have no backup plan for this?"
Selena sighed.
"No. He never really thought he'd be fatally injured like that," she admitted.
"So he never planned for how to turn back. Normally, he'd rampage for a while and then return to normal on his own. That was all he expected."
Erika grits her teeth.
She released the tension on her ribbons and let them slip free, then shot higher into the air as Akira lunged upward after her, claws barely missing her legs.
"But Muzan is still out there," Erika said urgently.
"We can't wait that long. Is there any other way?"
Selena went silent again, thinking.
Then.
"Well…We can always try the old method."
Erika blinked mid-flight.
"Old method?" she asked. "What is it?"
Selena replied, almost casually.
"Just have a heart-to-heart with him."