It was a night on the western coastal cliffs, where fierce waves roared as if to swallow the rocks.
At the precarious edge of that cliff, whipped by salt-laden night winds, Hokusai (Oei) stood.
She swung her brush as if dancing.
Wherever the brush tip touched, black ink splattered, and on the canvas, not a simple picture but a wave that seemed alive and undulating was being realized.
"Yes… this is it! Deeper! Darker! Like the eyes of the abyss gazing at me!"
Oei's eyes glittered with madness.
She was not painting the scenery of this world. She was capturing on the canvas a gateway to another dimension, a place connected to where the outer gods slumbered.
Then, behind her back, from the pitch-black darkness, a shadow crept out.
"Hehehe… How beautiful. That concentration, that vitality…"
Along with a fishy stench, a pot rose up.
From within it, Upper Moon Five, Gyokko, revealed himself, licking his lips as he looked at Oei's back.
"Nothing is as delicious as the soul of a human mad for art. If I put them alive in a pot and make them scream, what a beautiful sound it would make, better than any instrument~"
The small arms attached to Gyokko's body bent oddly as they stretched toward Oei.
It was the moment his sharp, small claws were about to snatch her slender neck.
Clang!
With a sharp metallic sound, sparks flew.
"...?!"
Gyokko flinched and stepped back. His claws had been blocked by something hard and bounced off.
As moonlight filtered through the clouds, a woman in a red kimono who stood between Oei and Gyokko was revealed. It was Tsubaki.
"Interrupting someone's artistic activity. What a fish with no manners."
Tsubaki aimed her Nichirin Blade with a cool gaze. Behind her, an illusion of red camellia petals scattering seemed to shimmer.
"Hoho? A demon? Like the Demon Slayer Corps but a demon… What a peculiar sensation."
Gyokko let out an unpleasant laugh as he tapped his pot.
"Who cares~ The price for interfering with my art is high! I'll turn you into fish food!"
Pots formed in his hands, and a horde of hideous fish covered in mucus poured out like a waterfall.
"Blood Demon Art, [Ten Thousand Sliding Sticky Fish]!!!"
Thousands of sticky fish bared their venomous fangs and swarmed Tsubaki.
"Hmph, crude."
Tsubaki scoffed and moved her foot.
"Blood Demon Art, [Blood Vine: Binding Thorns]."
Her shadow widened like a pool of blood, and from there, thorny vines surged up. The black thorns pierced and entangled the fish like living snakes.
Squelch! Crunch!
The fish burst, spraying sticky venom in all directions.
"Not bad! But I have other beautiful Blood Demon Arts…!"
At the moment Gyokko thought he had the upper hand, eerie presences were felt simultaneously from both his sides.
"My, Tsubaki-san. Having all the fun by yourself?"
With the moon at her back, a beautiful butterfly revealed herself.
"Insect Breathing, Butterfly Dance: [Play]."
A light and erratic movement, like a butterfly seeking nectar. Shinobu appeared before Gyokko.
Crunch!
Her needle-like sword precisely pierced Gyokko's eyeball.
"Gyaaah?!"
"You're late, Shinobu."
From the opposite side, Kocho Kanae unleashed a sword strike that seemed like scattering flower petals.
"Flower Breathing, Fourth Form: [Scarlet Flower Garment]."
The slashing attack, drawing an elegant curve, cut through the pouring sticky fish and rushed toward Gyokko's neck.
Crash!
Gyokko hid his body in a pot at the last moment, moving to another pot. The spot where he had been was deeply gouged by Kanae's sword strike.
Gyokko, who jumped out from a pot dozens of meters away, could not hide his bewilderment.
"You all… what are you? Not Hashira of the Demon Slayer Corps, yet with this level of skill. And those eyes… you're demons?"
He scanned the three women before him. They were powerful demons he had never seen, even as an Upper Moon.
"Could it be… you're the ones who killed Gyutaro and Daki? Perhaps, the traitors Master Muzan has been looking for lately?"
"Well? The dead tell no tales."
Shinobu smiled sweetly as she flicked Gyokko's blood from her sword.
"And since you'll soon be the same, there's no need for you to know."
"You insolent wenches… how dare you look down on me, Gyokko-sama?!"
Gyokko angrily prepared to use his Blood Demon Art again. But Shinobu gave him no opening.
Tap!
In an instant, Shinobu closed the distance and thrust her sword toward the pot Gyokko was hiding in.
Clatter~ Sizzle!
As the deadly poison on Shinobu's sword touched the pot, the pottery bubbled and melted away. Gyokko had already moved to another pot.
"My… my artwork!! How dare this ignorant wench!!"
"My, how noisy. Your artwork was too crude, so I refined it a bit for you."
Shinobu provocatively stuck out her tongue.
"Gyaaah!! I won't forgive you! I'll kill you all!!"
Gyokko, having lost his reason, shouted.
"Get out of the way! I can't concentrate with all this noise!"
At that moment, Hokusai, who had been silently painting, couldn't take it anymore and shouted as if about to throw her brush.
"Ah, sorry, Oei-san. I'll quiet him down right away."
Shinobu smiled and took a breath.
"Blood Demon Art, [Purple Poison Mist]."
From her mouth, a thick purple mist spewed out. The mist, as if alive, swept toward Gyokko. It was a deadly poison cloud that melted everything it touched.
"Guh! Poison mist?! Such a cheap trick!"
Gyokko sensed danger. To counter it, he generated a large number of pots in his hands.
From the ten pots he summoned in the air, an enormous amount of water gushed out. It became like a tidal wave, pushing back the poison mist.
Whooosh!!
The poison mist and water bomb collided head-on, creating a huge storm. Shinobu, Kanae, and Tsubaki agilely leaped back to avoid the spray.
But.
Splash!
One person who couldn't avoid it in time. And the canvas placed before her.
A massive wave of water engulfed Hokusai, and water poured over the abyssal wave she had poured her soul into painting.
Black ink smeared and flowed down. The wave painting that had seemed alive and undulating was crushed into a black stain, and the mysterious aura it was meant to capture vanished without a trace.
Silence fell over the battlefield. Gyokko breathed heavily, relieved that his defense had succeeded.
"Hehehe… see? My perfect defense~"
But his laughter did not last to the end.
Hssss….
Before the canvas, ruined and soaked. Hokusai, who had been bowing her head without moving, slowly, very slowly, rose.
Behind her small back, a black haze began to rise, swallowing even the starlight in the night sky.
"...You ruined it."
A low voice. But that voice instilled terror that seemed to scratch not his eardrums but his brain directly.
"My painting… you ruined it."
Hokusai raised her head. Her eyes were no longer human. Her pupils swirled with strange abyssal colors.
Grrrrrrr!
The ground shook. No, space itself was screaming. The black haze rising behind her gradually took on a massive form.
Numerous eyes, writhing tentacles, a bizarre and overwhelming shadow of a *Great Old One beyond human comprehension.
A shape reminiscent of a giant octopus or a god of death descended behind Hokusai.
"H… Hiiik?!"
Upper Moon Five, Gyokko, felt primordial fear for the first time in his life. It was different in quality from the fear he felt before Muzan.
This was not the fear of a living being, but cosmic horror, as if his very existence would be annihilated.
"Wh… what is that… what on earth is it?!"
Gyokko stepped back screaming.
Hokusai—no, Oei, who had drawn upon the power of the outer god—slowly raised a giant brush and aimed it at Gyokko.
"Let your life be the substitute."
With her voice, the boundaries of reality began to crumble. The sea, the sky, and the ground where Gyokko stood twisted into unknown colors.
"Sink into the abyss. Ph'nglui, Ph'nglui."
It was fear. Fear of the unknown. But, that didn't mean he would give up.
As if molting, he shed his skin, revealing his true form and mustering his full strength.
"No, no no no!!! This body cannot feel fear before anyone other than Master Muzan!!!"
Gyokko charged toward Oei, who was muttering. The three women considered stopping him, but it was awkward to interfere with Oei's affairs.
Thwack!!!
A fist swung to smash her head. But because she was staggering, it wasn't her head but her dangling right hand that was shattered.
To be precise, Oei, whose hand turned into a fish and fell off due to his divine hand.
Perhaps because she lacked magic resistance, or because she was mentally weakened from the shock.
"Heheh! Still nothing much!"
As Gyokko followed up with another fist to finish off Oei.
"Hey."
The world darkened.
Gyokko's body stiffened. It was a sensation similar to being oppressed by Muzan, no, incomparably greater than that, as if facing something unimaginable.
What was before his eyes?
"Who do you think you are, wrecking my daughter's hand. How important is a hand to our painter?"
Something changed.
From her vanished hand, from the severed arm, tentacles writhed and squirmed out.
Soon, it transformed into the shape of a hand.
Her appearance changed. Her form, her aura changed.
"You rootless vermin, who do you think you are to discuss art before my daughter and ruin her painting?"
Tsubaki, who was watching, couldn't breathe from the pressure, and Kanae and Shinobu also trembled under the intense pressure.
Akira's words flashed through Shinobu's mind.
`The strongest in our house is Shuten.`
`Yes, I know.`
`Usually, that is. If, when she gets serious. When she truly gets angry and uses her abilities, the strongest is someone else. Even I couldn't handle it.`
`Huh? Who is that? Ah, perhaps Benienma-san?`
`Hokusai.`
`That person?`
`That father and daughter aren't the type to enjoy fighting, and usually they just paint, so it seems that way. But if they get serious, it wouldn't be strange if the world ended. So Shinobu, you must never provoke those two. If other fools make them angry and the atmosphere turns strange, run away. Tell me.`
Now.
The moment of that warning was now.
"Ho, hoho?"
"Where did you learn the etiquette of messing with a married woman? You've made two mistakes. You wrecked the painting my daughter worked hard on, and you touched my daughter's body."
As the atmosphere grew ominous, Shinobu hurriedly took Tsubaki and Kanae and left the spot.
Ushigozen, who had been secretly hiding and watching the situation, hastily sent a message to Akira.
"Your life… cannot atone for it."
With her voice, the boundaries of reality began to crumble. The sea, the sky, and the ground where Gyokko stood twisted into unknown colors.
"Sink into the abyss. Become the pigment of my painting for eternity there."