Chapter 29: The Demonization of Nezuko

[Dark Alloy Battle Armor]—the armor was hard to draw; if anything seems off, please forgive me.

Boom! Boom!…

He fired several more rounds, but Mugen seemed to have figured out Zero’s weapon’s firing rhythm and dodged each shot at the exact moment it was fired.

After dodging this attack, he whipped his hand-held stinger lash sharply forward.

But each time, it was blocked by the Cross Floaters.

This made Mugen even more impatient! If Zero refused to become an Oni, then destroy him!

He would not allow any existence capable of threatening his ascension to the Ultimate Being to remain alive in this world!

So he increased the frequency of his stinger lash attacks!

Each strike against the Cross Floaters produced violent vibrations, even audible sonic booms!

“This guy’s attack speed is getting faster! I need to get closer to him! Otherwise, Aunt Kuzo might die!”

He glanced at Kuzo Kamado and the others protected by the [Quantum Shield], then at Mugen.

While continuing to fire at Mugen, he rapidly thought through his options.

“Use the [Dark Alloy Launcher]? No! Mugen’s attacks are too fast—he’ll deflect the missile before it reaches him!”

“[Dark Alloy Battle Mech]? No way—the mech’s destructive power is too great! There are trees and forests all around, and under these conditions, it could trigger an avalanche! Even my own people behind me could be killed!”

“[Dark Alloy Gatling]? No—even though its firepower is overwhelming and could suppress Mugen, it would expose my entire surroundings, giving Mugen an opening! And Mugen surely has other tricks up his sleeve!”

Clang!

The frontmost [Dark Alloy Cross Floater] was knocked away again by Mugen, landing at Zero’s feet, its surface still sparking and hissing—clearly drained of power.

Mugen had figured out the pattern: concentrate fire, and these strange crosses would lose function one by one.

Just need to concentrate fire again, increase the attack frequency, and soon all these crosses will be disabled.

Then, this demon hunter’s time is up!

Since he refuses to become an Oni, kill Zero—leave him alive just enough to turn him into an Oni later. One stroke, two benefits…

The battle intensified further; Zero thought long and hard, and finally devised a viable plan.

“Try that weapon!” Thinking this, Zero retracted the [Dark Alloy Annihilation Cannon Sniper] into his [Nanospace], along with the [Energy Flight Device] on his back.

Mugen saw him put away his weapons and assumed he was surrendering; he opened his mouth to speak—when suddenly Zero unfastened his cloak-hood and dropped it to the ground.

Huh~

Zero took a deep breath, forcing himself to calm down.

“[Dark Alloy Battle Armor], arm!”

Hum!

Ripples appeared in the space around Zero; numerous black-and-red metal fragments flew out, attaching piece by piece to his body.

Arms, torso, legs, head—all enveloped in a dark-red battle armor; he inserted a [Power Crystal] into the armor.

Armament complete!

Keng!

The armor’s fists slammed together with a sound; Zero directed the remaining six [Dark Alloy Cross Floaters] to surround the Kamado family, protecting them.

The last two were retracted into his [Nanospace] for repair after the battle.

“Mugen, the battle… has only just begun!”

He immediately activated the [Dark Alloy Battle Armor]’s maximum output power; the dark-red luminescence across its surface flowed like blood.

Seeing this, Mugen’s pupils shrank—his previous attacks had already been barely bearable; now this strange new thing filled him with dread.

The impenetrable armor encased Zero completely; his plan to inject his blood into Zero through attack vanished instantly.

“Aaaah!!! You pathetic human, if that’s how you want it, I’ll destroy you!!”

“Pathetic human? Mugen, hiding in this backwater country—do you really think you’re so powerful!?”

Boom!

Zero surged forward instantly, appearing before Mugen—so fast he punched straight through Mugen’s chest cavity.

Mugen was stunned by the speed; before he could react, his chest was pierced, and fury surged through him.

Blood Demon Art: Black Thorn!

Black thorns sprouted from Mugen’s arms, merging with his stinger lash and lashing out together.

Zero bent his body backward at a 90-degree angle to evade the strike.

He twisted his body, braced one hand on the ground, and kicked swiftly toward Mugen.

Mugen was struck again; his rage burned hotter.

His suit jacket tore apart; nine rope-like tubular whips grew from his back, each tipped with sharp bone spurs.

Each tubular whip, centered on Mugen, attacked Zero from different directions; every strike cracked the ground into craters.

Zero performed a backflip into midair to evade the whips, then landed on a tree trunk.

Using the trunk as a pivot, he pushed off hard and leapt upward, launching a kick from midair.

Seeing this, Mugen immediately gathered his nine tubular whips and stinger lash to strike Zero in the air.

Shhh!

But Zero’s form vanished instantly, reappearing behind Mugen—he delivered a brutal kick to Mugen’s head, spinning it 360 degrees.

Landing, he punched again, driving straight through Mugen’s back and into his heart.

But this wasn’t over—Mugen was a millennia-old Oni King; he whipped his tubular whips rapidly toward his own back.

Zero immediately retreated, reappearing before the Kamado family, holding a still-beating heart he had just torn from Mugen.

He crushed it with a single squeeze; the heart turned to pulp.

Mugen’s heart, torn away moments ago, had already regenerated—but fear stirred within him. He had never seen a human so formidable, one who could match him!

He might even be called a monster! No—centuries ago, he had met one such man… that man was the true monster.

The memory of that man’s face surfaced in his mind…

“Aaaahhh!! You damned bastard, why won’t you leave me in peace even in death!?” Mugen roared, swinging his stinger lash—but felt searing pain!

He turned his head—his left hand had been severed, and the wound burned fiercely, slowing his regeneration.

He looked back at Zero and saw he now held a glowing red tachi.

Seeing the red tachi, Mugen’s body began trembling again!

It was just now, when Zero attacked his heart, that he had retrieved one of the [Dark Alloy Four Styles]—pre-charged with a [Power Crystal]—and severed Mugen’s arm.

All that had happened in mere instants.

Seizing the opportunity, Zero charged again, wielding Style One; Mugen immediately used his remaining arm to cut off the burning section of his wound, regenerating instantly, then attacked again.

He swung his nine tubular whips and stinger lash once more!

Zero swiftly swung Style One to deflect the incoming whips and lashes, then flung Style One hard.

Style One spun at high speed toward Mugen.

Seeing this, Mugen whipped his stinger lash to knock Style One back.

But what Mugen didn’t expect—this was only a feint; Zero caught Style One, flashed instantly before Mugen, and slashed diagonally downward across his torso.

At that moment, Mugen’s body changed again—eight more tubular whips sprouted from his legs, identical to the nine on his back, but faster—so fast no afterimage remained!

Combined with the nine on his back, all seventeen whips swept toward Zero.

Zero instantly shifted from offense to defense, raising Style One to block.

Keng!

The whips struck Style One, sparking violently; Zero was pushed back a short distance.

The battle continued; the instant before Mugen’s next attack arrived, Zero charged again—this time targeting Mugen’s neck.

All whips fired at once; Zero leapt upward, twisted midair, and swung Style One with all his strength, severing several whips.

The whips burned with pain, enraging Mugen—he cut off the burned sections with his stinger lash, regenerated instantly, and attacked again.

“So this is it—Mugen himself isn’t powerful; it’s his many techniques, plus his unique physiology and some special condition, that make him hard to kill. Then…”

Zero pulled out Style Two from his [Nanospace], alternating it with Style One, charging forward to directly clash with Mugen’s whips and lash.

Ding! Ding! Ding!

During the charge, every whip strike was severed by Style One and Style Two.

But a few whips still struck the [Dark Alloy Battle Armor], leaving faint white scratches.

The surrounding trees and earth were shattered beyond recognition from their clash.

As Zero neared, Mugen swung his stinger lash; Zero slid low to dodge, then pushed up with one hand and kicked Mugen’s chin.

Crack!

Mugen’s jaw shattered, blood gushing.

Seizing the moment, Zero rose, swinging both Style One and Style Two together to sever Mugen’s neck.

He thought it was over—but suddenly, more tubular whips lashed from behind Zero.

Zero twisted his body, swung Style Two backward to cut the whips, flung Style One to spin around and return, then retreated swiftly.

Bang!

A massive explosion erupted from Mugen, unleashing a violent energy shockwave!

The environment grew even more devastated—snow melted, trees toppled in massive clusters.

Fortunately, the Kamado family was protected by the [Quantum Shield] and the [Dark Alloy Cross Floaters], spared further harm.

Otherwise, that shockwave would have killed them instantly!

The source of this energy shockwave was none other than Mugen.

At the moment Zero attacked Kibutsuji Muzan’s whip, he manipulated the stinger whip to sever the burned neck wound, completing his regeneration.

He gathered energy within his body, aiming to shatter Zero’s battle armor, but never expected Zero’s sensitivity to danger to be so acute.

The moment he sensed something amiss, he withdrew immediately—this was why the previous sequence unfolded as it did.

Zero launched another strike with Form One and Form Two, charging forward; Kibutsuji Muzan was now trembling with fear, transmitting a command to the Sound Hashira in his mind: “Muzan, get me back to the Infinite Castle immediately!”

TING!

A single string note rang out; behind Kibutsuji Muzan, a wooden door materialized out of thin air, and he instantly turned and stepped through into the Infinite Castle.

“Think you can run? Try this!” At the very moment Kibutsuji Muzan was about to turn and enter the wooden door, Zero pulled out the [Dark Alloy Missile Launcher], aimed it at him, and fired ten small missiles.

SHHH! SHHH! SHHH! …

Ten small missiles shot forth, their tails trailing long flames, directly piercing the wooden door before it could fully close.

BOOM! …

“AAAAAAHHHHH!!!!”

At the instant the wooden door began to seal shut, the missiles—still trailing fiery tails—exploded, and Kibutsuji Muzan’s agonized screams filled the air, brimming with resentment, fury, and shame!

The wooden door vanished after closing, as if it had never appeared at all.

Zero deactivated his [Dark Alloy Battle Armor] and retracted both it and the [Dark Alloy Missile Launcher] into his nanospace.

Gazing at the spot where the wooden door had vanished, then at the data displayed by his [Analytical Glasses], and finally at the small syringe he had crafted himself, the corners of his mouth lifted slightly.

【DATA COLLECTION SUCCESSFUL】!

Zero’s battle just now wasn’t merely to protect the Kamado family—he was also collecting data.

Sometimes excessive caution isn’t a bad thing; at least for himself and Xiao Yue, it granted another layer of survival information in this world.

Most importantly, he had obtained a blood sample of Kibutsuji Muzan.

“Hmph… Kibutsuji Muzan!”

He stopped thinking further and immediately turned to run toward Kamado Koyuki and the others behind him.

Seeing Zero unharmed and the monster gone, Kamado Koyuki’s taut nerves finally relaxed.

Zero deactivated the [Quantum Shield] protection mode via his [Analytical Glasses] and moved forward to check on them.

He found Kamado Koyuki’s breath unstable—fluctuating between strong and weak.

Nezuko’s breath was also extremely weak…

Rokuta was severely wounded…

“Zero… please… first… save… my child…” Kamado Koyuki finished speaking and collapsed into Zero’s arms.

Only then did Zero notice a large tear in the back of Kamado Koyuki’s clothing, her entire back soaked in blood.

Seeing this, Zero immediately retrieved the [Recovery Pod], but as he prepared to place Kamado Koyuki inside, he realized a major problem: what to do with her clothes?

He turned to Hana and said, “Hana, come here—I need your help with something.”

“Zero-nii… you… you say…”

Zero leaned close to Hana’s ear and told her what to do next; upon hearing it, her cheeks flushed red.

“I… I understand, Zero-nii…”

Then Zero carried Koyuki into the inner room, retrieved another [Recovery Pod], and stepped out, closing the door behind him.

The rest must be left to Hana—after all, both Hana and Koyuki were female, so this would avoid unnecessary awkwardness.

“Zero-nii, please, you must save my sister and Rokuta!”

“Please, I beg you!”

Takeo and Shigeru knelt before Zero, clinging to his legs and weeping.

“Don’t worry—I’ll save them, no matter what it takes.”

He approached Nezuko and Rokuta, but now only one [Recovery Pod] remained—what should he do?

“Zero… Zero-nii… cough… cough…” Nezuko’s faint voice sounded.

Takeo: “Sister!”

Shigeru: “Sister!”

Zero: “Nezuko! I’m here—don’t worry, I’ll find a way to save you both!”

“Zero-nii… please… first… save… Rokuta… I beg you… please?”

Hearing this, Zero’s pupils contracted—he understood what it meant.

It meant Nezuko was sacrificing herself to let Rokuta live.

Nezuko: “Cough… cough… I beg you!”

After a moment of inner struggle, he finally agreed: “Fine… I… I promise you.”

“Th… thank you…” With that, Nezuko slipped into “sleep.”

Zero forced down his anguish, lifted Rokuta, and placed him inside the [Recovery Pod], initiating treatment.

【KAMADO ROKUTA】

【SEVERE INJURY, POISONED, CRITICAL】

【REQUIRES 100 ENERGY CRYSTALS FOR TREATMENT】

Without hesitation, he inserted 100 [Energy Crystals] and activated the [Recovery Pod].

“Zero-nii, I… I’ve finished everything!” Hana stepped out of the inner room and spoke to Zero.

“Hmm…” He entered the inner room, inserted [Energy Crystals], and began treating Kamado Koyuki.

Returning to the living room, he saw Takeo, Shigeru, and Hana gathered around Nezuko, weeping uncontrollably—Zero’s heart ached.

He walked to Nezuko’s side, held her in his arms, and stared at the little girl—his mind flashed back to a hazy memory from long ago…

“I’m sorry!”

Yet Zero didn’t notice that Nezuko’s wounds were slowly healing on their own—and from her mouth, two sharp fangs were beginning to grow.