"What!?"
"What just happened?"
The sudden explosion drew every demon's attention. The sheer destructive power reminded the Kizuki of Douma's memories, transmitted into their minds by Muzan.
"Those strange weapons we've never seen before?"
Gazing at the fireball from the micro-bomb, the Kizuki's expressions varied—fear, horror, wariness—all fixed on Reverie.
"Lord Muzan!" Kokushibou's six eyes widened abruptly, turning toward Muzan's direction.
"Oh my, getting distracted in battle is quite rude, you know~!" Kochou Kanae's black-purple hair danced, her radiant pink-purple eyes sparkling, lips curving into a charming arc.
"Sun Breathing, Form Six: Bone-Burning Solar Blaze!"
Golden flames spun outward like solar flares. Seizing Kokushibou's lapse, Kanae struck, wounding his left arm and right shoulder.
The cuts burned like flames, slowing his regeneration.
Kokushibou eyed Kanae gravely, baffled by how such a delicate girl wielded such terrifying strength and speed.
But one thing was clear—he couldn't underestimate her anymore.
"You're right, my lady." Kanae's prowess earned Kokushibou's respect. Taking a deep breath, he declared, "Let's begin!"
"Moon Breathing, Sixth Form: Endless Night Lone Moon, Unceasing."
Without a visible swing, overlapping blade lights pierced heaven and earth, countless crescents, large and small, shifting and spinning, surging wildly in all directions.
Kochou Kanae glanced at Reverie and Shiraki, her eyes crinkling with a gentle smile. "Sun Breathing, Seventh Form: Solar Flare Thrust."
Scorching winds tore the air, distorting it. The heated blade seared the atmosphere, raising the temperature.
The clash of sun and moon reignited.
By the way, the Sun Breathing Kanae used wasn't the true, complete Sun Breathing but the version Tanjuro reverse-engineered from its forms.
How much of the true Sun Breathing's power it held, Kanae couldn't say—she'd never seen the real thing.
What she knew for sure was that it outclassed other derivative breathing styles by at least one or two tiers!
"AAAAHH!!!"
Glaring at the blue-haired girl beside Ubuyashiki, who'd killed Douma, Muzan's furious roar echoed through the night.
"You useless trash, kill her!"
An almost tangible pressure descended, fear crystallizing into icy chains binding their blood, overriding the Kizuki's caution and dread of the unknown.
All demons, save Upper Rank Three, widened their scarlet, ferocious eyes and charged at Reverie in her pure black dress from different angles.
Akaza, as if sensing something, turned toward a certain direction.
"Amitabha, you won't succeed!"
Himejima Gyoumei chanted a Buddhist prayer, his massive arms swinging, chains clattering like writhing snakes. His meteor hammer shattered the air, streaking forward.
"Destructive Kill: Chaotic Style!"
Akaza didn't kill women; he only craved battles with the strong.
Unleashing his immense power, Akaza's clenched fists, swinging with his arms, exploded the air, striking the meteor hammer.
Violent winds and shockwaves collided, crowding the space.
The other Pillars followed close behind.
"Mist Breathing, Fifth Form: Sea of Clouded Mist!"
"Flame Breathing, Fifth Form: Flaming Tiger!"
"Love Breathing, Third Form: Cat-Love Shower!"
"Serpent Breathing, Fourth Form: Coiling Nest!"
"Water Breathing, Seventh: Drop Ripple Thrust!"
Blade lights danced, clashing auras of varied forms surging higher.
These were wide-range attack techniques, all high-difficulty "forms" from advanced stages.
The gap between the Twelve Kizuki's Lower and Upper Ranks was vast, and among the Upper Ranks, the top three and bottom three were leagues apart, with One, Two, and Three forming distinct tiers.
The six Lower Ranks were cleanly dispatched in the first clash by the Pillars, who went all out.
Kochou Kanae soloed Kokushibo, Himejima Gyoumei faced Akaza alone, gaining the upper hand, while the other Upper Rank Kizuki ganged up, overpowering the remaining Demon Slayer Pillars.
After all, this moment was years before the original Infinity Castle battle. The Pillars hadn't awakened their Marks, and their baseline strength was far weaker.
Though Tanjuurou Kamado, now a Demon Slayer Corps instructor alongside Kanae, had shared his breathing insights unreservedly, helping the Pillars refine their styles, it couldn't bridge the gap time created.
But it didn't matter.
"Wind Breathing, Fifth Form: Cold Autumn Mountain Gale!"
Cyan light solidified into tangible gales swirling in the air. Sanemi Shinazugawa's peripheral vision locked onto the courtyard's depths.
"Alright, Mr. Ubuyashiki, it's time for you to leave. Staying here will definitely get you caught in the fight's aftermath."
Filming the battle, Shiraki turned to the man behind him.
With Reverie here, Muzan wasn't escaping today, giving Shiraki ample confidence to go wild.
Not entirely wild, mind you—mainly, Kanae had only recently learned Sun Breathing and wanted to practice against a demon.
Muzan's level was too high for her to solo, negating the training benefit, but Upper Rank One was perfect, matching her needs in every way.
Ubuyashiki turned his nearly blind eyes toward Muzan, then scanned his wife and children around him. "Very well, though it's a shame I can't witness Muzan's end with my own eyes."
He knew staying would only burden everyone.
But for the Ubuyashiki family, cursed because of Muzan, missing his demise firsthand was truly regrettable!
"No, trust me, you'll see it." Shiraki handed the camera to Kochou Shinobu. "Little Shinobu, take this, escort your lord out, and keep them safe."
"Got it, leave it to me!" Shinobu nodded firmly, then grabbed Shiraki's arm, her face etched with worry. "Brother-in-law, aren't you leaving with us? It's too dangerous here!"
Shiraki smiled gently, patting her head. "Your sister… cough, your brother-in-law isn't some frail nobleman."
Kochou Kanae's mastery of the Kagura of the Fire God and Sun Breathing in just over ten days owed much to 'her' efforts.
Shiraki, Reverie, and even Kiana in the Elysian Realm had trained together.
Like Naruto Uzumaki using Shadow Clones to train, it was triple the experience points!
Be it combat experience or mastery of forms and breathing, Shiraki fully synced with Kanae.
From breathing style newbie to master in less than a month, Shiraki could thump his chest and proudly shout, I got strong all by myself!
"Hey, little bro, lend me your Nichirin Blade." Shiraki unceremoniously drew the blade from the waist of a Class-A swordsman tasked with escorting Ubuyashiki.
Twirling a Flower Breathing form, Shiraki eyed the cyan Nichirin Blade, took a deep breath…
The sound of flowing air—Shiraki exhaled scorching white mist. In a few breaths, the blade's cyan hue turned sun-red.
This blade was now fully in Shiraki's shape!
The Class-A swordsman silently watched his beloved blade change colors.
"Don't give me that look; I'll return it later," Shiraki said politely to the nameless swordsman. He was a pure-love warrior, after all.
"That's… Sun Breathing!?" Kochou Shinobu stared, shocked, at the blade in Shiraki's hand.
"Yep, believe me now?" Shiraki flashed a dashing smile.
The stunned look faded quickly. Ubuyashiki bowed deeply in thanks, then withdrew under the protection of several Class-A swordsmen and Shinobu.
Ubuyashiki's departure was like a signal.
Upper Rank Four, Hantengu; Five, Gyokko; Six, Gyutarou and Daki—three Upper Ranks by name, but eight demons in practice!
Daki was just an accessory, but she granted Gyuutarou greater immortality; unless both their heads were cut simultaneously, he wouldn't die.
Upper Rank Four, Hantengu's Blood Demon Art created clones, each with near-Pillar-level strength.
The Pillars, suppressed by eight demons, had mostly used defensive techniques, taking some injuries but nothing serious.
Seeing their lord finally leave, including the Rock Pillar battling Akaza, the Pillars shared a collective sigh, exchanging a tacit glance.
Brothers and sisters, time to pop off!
Under the demons' baffled and uncomprehending stares, the Pillar swordsmen sheathed their Nichirin Blades and pulled black cylindrical objects from their cloaks.
The demons didn't know what they were, but Douma's precedent told them their power.
Too late!
"Demons, die!!!"
With hatred-fueled roars, the swordsmen pulled the pins, hurling World Serpent's high-explosive grenades at the Upper Ranks.
World Serpent held many Previous Era relics, their grenades outclassing Anti-Entropy's.
Shiraki mentally gave them a thumbs-up.
Even as the Upper Ranks reacted and fled, they realized too late that the Pillars had subtly guided them into an open battlefield with nowhere to run.
Boom! Boom! Boom!
BOOM—! BOOM—!
Even with Akaza's honed body and battle aura shield, carbon-based lifeforms were like plastic against heavy firepower—well, this world's carbon-based lifeforms.
The fierce blasts, with deafening roars, whipped up wild winds, scattering flames and shattered corpses from the sky like a rain of fire and blood.
After the Upper Ranks were first pulverized, prepared Demon Slayer swordsmen hauled crates of grenades and bombs to their Pillars' sides.
"Moon Breathing, Form Eight: Moon Dragon Tail Sweep."
A purple dragon seemed to swing its massive tail, a plain horizontal slash radiating excessively dazzling light.
Blocking Kanae's technique with Form Eight, Kokushibou still faltered, his expression as lifeless as a corpse.
This wasn't swordsmanship at all!!!
Kanae didn't seize the chance to press, as Shiraki approached.
The girl obediently offered her palm to Shiraki, parting after a brief touch.
"Don't worry, I won't use 'Gun Breathing' or 'Bomb Breathing' on you."
Without words, Shiraki and Kanae passed each other, like swapping players in a game.
"Whether it's the other Upper Ranks or Muzan, don't worry about them. Next, just spar with me and hone my swordsmanship~!"
Reverie skipped cheerfully to Kanae's side. This was Kanae's world, where her parents were killed by demons—she deserved to take revenge herself!
"Hey, Mr. Muzan Kibutsuji, your time's up~!"
Kochou Kanae, holding Reverie's hand, approached Muzan, who was being blasted back and forth by micro-remote bombs. Her gentle, warm smile vanished for the first time.