Chapter 53: Butterfly Shinobu: Brother-in-law

“This man is the Demon King—Kibutsuji Muzan,” Zero said calmly.

Yet the people in the room were anything but calm!

They never expected Zero to encounter Kibutsuji Muzan again—this was the second time!

Immediately, Zero enlarged the female demon beside Kibutsuji Muzan, who held a shamisen, and displayed her to everyone.

This demon is Meiyo. Though not among the Upper Moons, she is far from insignificant! In this footage, the location where I stand is the Infinite Castle—entirely controlled by her!

“She can transport the Infinite Castle to any location, or forcibly teleport targets anywhere—or into the Infinite Castle itself.”

“As for the Infinite Castle… I’m sorry, but I cannot determine its exact location…”

Everyone gasped at these words.

They never imagined just one female demon could control such a vast Infinite Castle.

No wonder the Demon Slayer Corps had never found Kibutsuji Muzan—all this time, he had such a powerful ally at his side!

But everything changed after Zero joined the Demon Slayer Corps.

At that moment, Ubuyashiki Kagaya stood up, bowed deeply to Zero, and said: “Zero, thank you for your immense contribution to the Demon Slayer Corps. The Ubuyashiki family and the Demon Slayer Corps will never forget your aid.”

Seeing this, everyone else rose to their feet and bowed to Zero as well.

“What are you doing? Get up—this isn’t necessary!” Zero rushed forward, grabbing Ubuyashiki Kagaya’s arm to stop him and the others.

“I am a Pillar of the Demon Slayer Corps. This is my duty as a Pillar!”

“Kanae, Mitsuri, and everyone else—please, stand up.”

After much persuasion, they finally stopped bowing.

They returned to their seats and continued watching the battle on the projection screen…

On the projection screen, the female demon plucked her shamisen, and instantly five demons appeared around Zero—including Upper Moon One.

They formed a circle, surrounding Zero completely.

Even the strongest Pillars present felt immense pressure pressing down on them.

Especially since the numbers etched in their eyes were unmistakable—all Upper Moons!

Zero clicked pause on the projection, manipulated the interface, lined up the five Upper Moons side by side, then dragged one forward to display it again.

“This is Upper Moon Three—Akaza. The strongest fighter among the Upper Moons, excluding Upper Moon One and Two…”

Zero explained every detail about Upper Moon Three to everyone, clearly outlining critical points to note.

He then set Upper Moon Three aside and clicked on another demon, enlarging it.

This demon appeared no larger than a palm—impossible to associate with an Upper Moon.

“This is Upper Moon Four—Shinobu… no, Hantengu… Don’t be fooled by his tiny size—his Blood Demon Art is anything but ordinary!”

Seeing Hantengu made him furious, nearly causing him to misname him.

He resolved inwardly: when he next encountered Shinobu Dog, he’d beat him again to vent his rage—and then kill him.

He then explained all information and key details regarding Upper Moon Four.

Far away in the Infinite Castle, Hantengu shivered with sudden dread, as if sensing someone intended him harm.

“I’m just a poor, weak soul…” he thought, yet his most urgent concern now was enduring another beating from Akaza.

He hoped Akaza would be somewhat calmer after hitting him…

After explaining Upper Moon Four, Zero clicked on the final two demons, enlarging them for everyone to see.

These two demons were a brother and sister, both with the characters “Upper Moon Six” etched in their eyes.

“These are Upper Moon Six—the twin demons. The male is Giyu Tomioka, the female is Shinobu…”

He similarly explained all information and precautions regarding Upper Moon Six.

Yet Shinobu Ubuyashiki noticed something else.

Zero had not mentioned anything about Upper Moon Two.

So he asked: “What about Upper Moon Two? Why haven’t you told us anything about him?”

But Shinobu Ubuyashiki immediately regretted asking.

Zero’s reply was simple: “Upper Moon Two… I will kill him myself!”

“Why?” Shinobu Ubuyashiki asked.

Zero said nothing, only turned his gaze toward Kanae.

Kanae, met with his stare, lowered her head shyly—she knew exactly why he said that.

But the next words from Butterfly Shinobu nearly ignited Shinobu Ubuyashiki’s temper.

“It was Upper Moon Two who nearly killed my sister. I think… Brother-in-law wants to avenge her himself, right?”

Butterfly Shinobu now addressed Zero as “Brother-in-law.”

She deliberately stressed the words “Brother-in-law,” sounding deceptively cunning.

Shinobu Ubuyashiki: …

Damn it, I shouldn’t have asked!

More damn love-dump!

Tch…

Decided: tonight, I’ll return to Zero’s territory and kill every demon there.

Hehehe…

(Demons: Wait! What’s this got to do with us?)

Uzui Tengen rubbed his chin and said: “What a splendid youth!”

The minor interruption didn’t concern anyone—their eyes remained fixed on the battle on the projection screen…

In the battle, the Upper Moons unleashed Blood Demon Art after Blood Demon Art, and Zero narrowly dodged each one before counterattacking.

Yet despite his skill, Zero was struck, sustaining injuries.

Kanae and Mitsuri gripped their collars tightly.

Their hearts felt torn out, filled with nothing but worry for Zero.

Under such conditions, Zero still survived—if anyone else had been in his place, they’d have been reduced to ash long ago…

‘Heh… Hahaha… Interesting. Extremely interesting…’

‘Dark Alloy Armor—Arm!’

In the projection, Zero’s body was armored, four katana appearing behind him as he charged back into the fray against all the Upper Moons!

Hantengu’s four clones had their heads severed, yet their bodies remained intact, not turning to ash…

Again and again, he fought, again and again, dodging deadly attacks by a hair’s breadth…

Until finally, all the Blood Demon Arts converged into one massive blast, hurling toward Zero—creating a thick black fog…

At that moment, everyone felt the power of that strike—and wondered: how would Zero escape this impossible situation?

When the black fog cleared, Zero deactivated his armor, holding his sniper cannon, and fired a shot directly at Kibutsuji Muzan.

Muzan dodged it—the bullet struck the female demon behind him, Meiyo.

At that moment, everyone noticed: Hantengu’s four clones had vanished. In their place stood a young demon holding an ‘S’-shaped drumstick, with a thunder god drum on his back inscribed with the character ‘Hate.’

‘Unpleasant! Utterly unpleasant! Wicked ones—die and atone!’

Boom! Boom!

Hate Pearl struck the thunder god drum on his back, releasing two massive Blood Demon Arts.

Yet Zero always evaded them with uncanny precision…

Then Zero pulled several strange objects from thin air and hurled them—blinding white light erupted…

Finally, even Kibutsuji Muzan entered the battle, joining the Upper Moons in attacking Zero…

Everyone in the room broke into cold sweat—could Zero possibly survive this?

But they had forgotten one thing: if Zero hadn’t survived, he wouldn’t be here now, explaining the Upper Moons’ intelligence to them.

‘Battle Mech—Activate!’

Two colossal mechanical arms suddenly extended from the void, shielding Zero.

Every attack struck the mechanical arms—and all were absorbed.

Only then did they realize what it was!

It was that steel monster—the one they’d seen once before at Zero’s residence!

Zero fired another shot at Meiyo, blasting her into fragments.

Then he entered the steel monster’s core and began piloting it to counterattack.

Under Kibutsuji Muzan’s command, all the Upper Moons unleashed their full strength against the steel monster.

But it was all futile.

Not only did the attacks fail to damage the mech, but each Upper Moon was swiftly reversed and killed by Zero.

The first to fall was Gyomei.

His ice bodhisattva was crushed by a single punch from the steel monster, and Gyomei himself was stomped into pulp.

The audience felt as if Zero in the projection… carried a deep hatred, stomping repeatedly before finally stopping…

All eyes turned to Kanae, then to Zero—and remembering Butterfly Shinobu’s earlier words, they seemed to understand…

Zero truly dotes on her…

‘War Stomp!’

The battle in the projection continued—the steel monster leapt high, then slammed down, nullifying Hate Pearl’s Blood Demon Art and crushing him beneath its foot…

Akaza’s attack followed—but was punched away in a single blow…

Hei Simum leaped onto the steel monster’s shoulder, but before he could activate his technique, he was snatched up, slammed into the ground, then punched into shards…

The female demon named Daji, one of Rokugen’s Upper Moons, attacked the steel monster with her belt—but the belt was seized and whipped like a propeller, hurling her into the ceiling…

Kibutsuji Muzan’s other Upper Moon, Kyujuro, was slapped clean away…

Kibutsuji Muzan seized the moment to strike, only to be smacked straight into the ground; just as the steel monster was about to crush him beneath its foot, he split into countless fragments and escaped…

‘Launch all missiles!’

Everyone saw twenty missiles fire from the steel monster’s arms, blasting toward the Upper Moons, the Sound Hashira, and Kibutsuji Muzan…

Finally, the steel monster drew two massive swords from its back and sprinted through the Infinite Castle, destroying everything in its path…

Those in the room could no longer find words to describe Zero…

They could even feel Kibutsuji Muzan’s despair…

A sliver of pity stirred in their hearts for Kibutsuji Muzan.

Why did you, Kibutsuji Muzan, have to provoke Zero of all people?

That’s just asking for it!

Who doesn’t know Zero is more monstrous than any monster?

At the same time, they were deeply relieved Zero was on the Demon Slayer Corps’ side.

If Zero were a demon, the Demon Slayer Corps wouldn’t last a day—no, not even a few minutes—before being utterly annihilated!

In the final moments of the projection, they saw the Infinite Castle reduced to ruins, everything in chaos.

Kibutsuji Muzan, seeing the Sound Hashira had regenerated, ordered her to teleport Zero out of the Infinite Castle—but the steel monster’s massive body got stuck.

They watched as the Sound Hashira frantically plucked her koto, finally ejecting Zero and the steel monster from the Infinite Castle…

But at the very end, they seemed to see three strange black objects launched from the mech’s arms, falling into the ruins of the Infinite Castle—what were they?

(Muzan: …)

The projection ended here.

Zero tapped the air; the projection shut off. He pulled back the curtains and opened the window—sunlight flooded the room.

Then Zero picked up several sheets of recorded paper from the bed and handed them to Ubuyashiki Kagaya.

‘Lord Ubuyashiki, these contain all the information I recorded on the Upper Moons. I’ve marked the critical parts in red. Please have someone transcribe them and distribute copies to every Pill.’

Ubuyashiki Kagaya took the papers; they detailed every Upper Moon, including the Sound Hashira, exactly as seen.

The vital sections were clearly marked in red by Zero.

‘Zero, thank you. With this, the Demon Slayer Corps now holds full knowledge of the Upper Moons—and every swordsman’s life will be better protected!’

‘No need for thanks. I’m a member of the Demon Slayer Corps. This is my duty.’

After a brief discussion with the others, they prepared to leave.

Just before departing, Zero asked several Pill members to stay behind.

‘Gyomei, Kyojuro, Shinobu, Mitsuri, Giyu—stay a moment.’

Though puzzled, the five obeyed.

‘Kanae, Mitsuri, you two leave first.’

‘Mm.’

‘Alright.’

Ikki Shinku felt an inexplicable surge of jealousy at Zero’s familiar address to Mitsuri.

But remembering Zero might have something important to say, he suppressed it for now.

After the others left, Zero retrieved two [Recovery Pods] from his [Nanotech Space] and placed them in the room.

‘Kyojuro, Giyu, do as I say: strip naked, get inside, and I’ll treat your old injuries. I’ll be back in two minutes.’

Without waiting for their reaction, he left the room with the other three, waiting at the door.

What’s there to see in a boy taking off his clothes?

Better to watch my girlfriend Kanae and Mitsuri…

Cough—now’s not the time for that. I’m not even there yet with Kanae and Mitsuri.

At the door, Gyomei asked, puzzled: ‘Zero, why say you’re treating our old injuries?’

Zero replied: ‘Kyojuro’s eardrums are ruptured. Giyu has countless old wounds. They’re used to them, but over time, they cause hidden damage.’

The Pill members knew this already, so they weren’t surprised.

Zero continued: ‘Kyojuro shouts constantly. His personality wins everyone’s affection—but when others speak too softly, he can’t hear them and yells back, scaring people and causing misunderstandings.’

‘As for Giyu… his wounds are mostly old ones, seemingly cauterized with something to stop bleeding. Over time, this has caused irreversible muscle damage.’

‘His self-treatment works—but if he reopens an old wound during battle, he could be left vulnerable. These are only my speculations, but who can predict the future?’

These words left Gyomei, Shinku, and Shinobu in deep thought…

The current situation was no longer like the past. Since Zero joined the Demon Slayer Corps, many things had changed…

Future battles might not be against low-tier demons or Lower Moons.

They might face Upper Moons…

Ikki Shinku pondered a moment, then turned to leave—but Zero gripped his shoulder.

………