When they declared that only Sun Breathing could kill them, Nightingale paused for a moment.
Of course, she knew about Sun Breathing—after all, it was the original of all breathing techniques, the strongest style used by Tsugikuni Yoriichi.
The problem was… since when was Sun Breathing the only way to kill Hantengu?
From what she remembered, the reason cutting off Hantengu's head didn't work was because it was always just one of his clones. Only by severing the true body—a creature the size of a mouse, with "Cowardice" (怯) written on its tongue—could you actually kill him.
Hantengu's words didn't match Nightingale's understanding, leaving her puzzled.
Is he lying? Or did Kibutsuji Muzan give Hantengu a secret power-up?
Either way, it didn't matter.
True or not, Nightingale couldn't be bothered—she didn't know Sun Breathing anyway.
And even if she didn't have Sun Breathing, so what? Even if Hantengu had been strengthened, as soon as the sun rose in the east, not even Muzan himself could escape annihilation. She simply didn't believe Hantengu had conquered sunlight too.
Her muscles drew taut, like a bowstring pulled to the limit. The oppressive aura seemed to bend the very flow of the air.
The three demons facing her looked like prairie dogs before a charging locomotive.
Aizetsu and Karaku gripped their weapons, bracing themselves, while Urogi—the only one who could fly—spread his wings and shot skyward.
All of Hantengu's clones had special abilities. Urogi could fly at high speed and unleash ultrasonic waves that shattered even solid rock.
As he soared, Urogi opened his mouth, gathering power for a sonic attack.
But in a dizzying instant, a white-gloved hand seized his face out of nowhere.
On the ground, Aizetsu and Karaku jolted in alarm, looking up at Nightingale in terror.
So fast!
"Emergency treatment!"
Beneath the gloomy night sky, Nightingale's crimson eyes flashed with a manic brilliance.
"Now rest!!"
Karaku and Aizetsu sprang away with all their might, covering more than ten meters in a blink. The next moment, Nightingale—gripping Urogi's head—came crashing down from the sky like a meteor, shattering the earth.
Cracks spiderwebbed outward from the impact, blasting dirt and debris as a gale swept outward.
At Nightingale's feet, Urogi—reduced to just two twitching legs—began to regenerate with frightening speed. Nightingale paid him no mind, instead slowly raising her right hand, fingers splayed.
A cold gleam flashed as the sorrowful Aizetsu lunged in, cross-spear jabbing like lightning—the sound of air splitting clear as day.
CLANG—
A spear so fast and skillfully thrust that it should have pierced anything.
But when the tip struck Nightingale's palm, all that rang out was a sharp metallic chime.
Aizetsu's mind went blank.
His arms bulged with effort, the shaft of the spear bowed, his face twisted with strain.
And yet… the blow couldn't even pierce that pristine white glove.
The force recoiled up the shaft, tearing the flesh between Aizetsu's thumbs and forefingers—but such wounds healed in less than a second.
Still, no amount of regeneration could calm his thundering heart.
How can she be this tough? Is this really a human body?!
The longer the fight dragged on, the more Aizetsu felt the vast gulf between their strength—a chasm that seemed utterly unbridgeable. If the only problem wasn't that she lacked the means to kill them, if this weren't a direct order from that man, he'd have run off with every clone long ago!
And now, Hantengu burned with anger and resentment.
Why am I the one stuck fighting this monster, while that loser gets to go somewhere else?
Suddenly, Aizetsu froze.
The air itself seemed to solidify, making even the tiniest movement a hundred times harder.
That sense of hair-raising danger—they'd all felt it before… It always came right before that monster of a woman attacked.
Nightingale's eyes narrowed. She stepped forward, her free left hand sweeping out with hurricane force.
BANG!
The force shattered the ground, sending Aizetsu flying like a cannonball, smashing through tree after tree before embedding him deep into a mountainside.
"Urgh—cough!"
Thick, dark blood—mixed with fragments of organ and bone—poured from his mouth, nose, and ears.
A huge dent caved in his torso, both arms twisted at impossible angles, and he still clutched the two broken halves of his cross-spear.
Just before the blow landed, Aizetsu had yanked the spear back to block, using its destruction to barely avoid having his whole upper body obliterated.
Behind Nightingale, the three other demons struck all at once, launching a barrage that caught her seemingly off guard.
Sekido's lightning, Urogi's soundwave, Karaku's hurricane—a triple onslaught of elemental devastation smashed down, engulfing Nightingale's silhouette.
"Well?" Sekido called out, a trace of doubt in his voice. "That has to have worked, right?"
Suddenly, a breeze stirred at his side, rustling his hair. Anxiety crept into his eyes.
The hem of a white coat fluttered—Nightingale was behind him, back to back, feet planted lightly on the ground.
Sekido gritted his teeth, spinning and smashing his staff at her head, only for Nightingale to grab it mid-swing. All his furious strength was swallowed whole, not even a ripple.
"Damn it!"
Sekido's face went pale. No matter how hard he pulled, he couldn't free his weapon. In desperation, he tried to unleash a lightning strike.
But before he could, Nightingale's fist shattered his torso in a single blow.
Not giving anyone time to react, she raised the stolen staff high and brought it crashing down on Karaku, smashing him into a bloody smear. In the same motion, she spun and hurled the staff like a javelin, skewering Urogi's head out of the air.
It took longer to describe than to do—Nightingale dispatched all four of Hantengu's clones in just a few seconds, and her coat was barely dirtied.
The demons' regeneration was still fearsome—even when pulverized, they could re-form in the blink of an eye. They glared hatefully at Nightingale, but she didn't care.
She could see their healing was slower now, just a bit. Each regeneration cost them more of their stored life force; if that ever ran out, they'd die whether or not a Nichirin Blade or sunlight was involved. The problem was, demons could always recover by eating humans, so wearing them down was no easy feat.
"This disease is especially stubborn," Nightingale remarked as she adjusted her gloves, relaxing her wrists and shoulders. "But that's fine—cases like this are nothing new. You'll have to try harder if you want to wear me out."
She didn't know what Hantengu's true aim was, or why they insisted on a fight with no hope of victory. From the looks of it, they intended to drag this out. Nightingale was unfazed—she'd long since grown used to stubborn opponents, whether human or disease.
Just as the fight was about to resume, Nightingale's expression suddenly changed.
What's this…?
She tilted her head, fixing her gaze in a new direction. "A new disease?"
…
In the shadowed woods, the night wind rustled the leaves with a soft shhhhhh.
CRASH!
A huge tree was felled, collapsing with a thunderous crash.
The thing that brought it down could only be called a monster.
It stood as tall as a small house, its body like a grotesquely oversized fish—except this fish had rows of knife-sharp teeth and several human-like arms supporting it on land. On its back, it carried a jar.
Fish and human arms sewn together, the creature looked like the failed experiment of a mad scientist… And it wasn't alone. More and more of them emerged, surrounding the abandoned temple where Afune and the others were staying.
"Ugh… Why do I have to be stuck here? I really wanted to see her for myself… the woman even that man is so interested in."
The speaker was a demon whose very appearance was nauseating.
His head sprouted not hair but writhing arms; in place of eyes, two mouths babbled constantly, while his mouth was an eye marked with the kanji for "Five" (伍). On his forehead, a vertical "Upper Rank" (上弦) eye gleamed. He slithered out of a jar, body twisting like a snake.
His identity was obvious—Upper Moon Five: Gyokko.
"What an honor, what misfortune… To catch that man's eye—what could make someone so special? What secret does she hold? My curiosity burns! If I use her, I, Gyokko, could create a masterpiece the world has never seen!"
Malice hung thick in his words. Whatever "artwork" he imagined clearly wasn't anything good.
Even as a human, Gyokko had stitched together fish of different kinds, storing scales and bones in jars, and called it "art."
When he was a child, his parents drowned at sea. By the time they were found, their bodies were bloated and decayed, and while the villagers mourned, only Gyokko admired the swollen corpses as "artistic."
After becoming a demon, his craving for "art" only intensified. He now stuffed living humans into jars, sewing them together to create his grotesque pieces—often gifting his favorites to other Upper Moons. Only Dōma ever bothered to praise his creations.
This time, Gyokko and Hantengu had both received orders from Muzan: work together to investigate a single person.
The assignment was split: Hantengu would confront Nightingale directly, while Gyokko attacked her companions—knowing full well that humans sometimes drew out unexpected strength protecting others.
The reason was clear—they were here to observe Nightingale, not simply to slaughter Shinobu and the rest. Hantengu's clones were too powerful; if they wiped out everyone in the temple immediately, their investigation would go nowhere. So Gyokko was assigned to send his fish-monsters instead.
Of course, Gyokko resented the task—he was dying to see what sort of woman could attract Muzan's personal interest. But Hantengu outranked him, and these were Muzan's orders, so Gyokko dared not disobey.
I hope Hantengu doesn't go overboard… At least leave me a relatively complete corpse! Such rare material—what a shame it would be to miss out!
He turned his attention to the temple.
Not as precious as that woman, but still, several young, beautiful girls… As raw materials for my new masterpiece, they'll do. Although… Is that a baby boy among them? My art has no need for such useless extras. I'll just kill him outright.
His words oozed contempt and arrogance. To Gyokko, both Nightingale and the temple's residents were nothing but materials for his next creation. He looked down on every being except Muzan, always mocking them as clueless fools who couldn't comprehend art.
Looks like there are Demon Slayers inside, too? All the better—I'll use them and the other humans in a single work. Let their blades skewer the heads of innocents; yes, yes, and I'll fill the Demon Slayers' bellies with human viscera… Inspiration! Endless inspiration! The theme is the folly of would-be protectors slaughtering those they swore to defend! Truly, Gyokko, you are a master! Hahaha!
Growing more and more excited, Gyokko directed his fish-beasts to surround the temple where Afune and the others sheltered.
Then, suddenly, he sensed something and looked up.
High above, a streak of emerald light sliced through the darkness.
The meteor fell, impossibly fast—before Gyokko could react, it crashed through the jar on one of his fish-beasts' backs.
With the jar shattered, the fish-beast let out a shrill, agonized shriek and, like a demon decapitated, its enormous body disintegrated to dust.
More and more emerald meteors rained down, each one targeting a fish-beast with unerring accuracy.
"My jars! My masterpieces! Who dares? What lowlife dares to ruin my art?!"
Watching his summoned monsters being annihilated in the blink of an eye, Gyokko howled in fury and disbelief.