Chapter 10: Demon Slayer Blade, Part 5

After the Hashira meeting, I returned to my routine.

I hunted demons, honing my skills, and spent time with those who had become dear to me at the Butterfly Mansion – Shinobu, Aoi, and others.

It was a time of happiness.

However, as if to prove the law of conservation of energy, misfortune arrived, carried on the wind.

“What?”

Upon returning to the Butterfly Mansion after a demon hunt, I received shocking news.

Shinobu had departed to eliminate the demon on the Mugen Train.

Why?

The timing was wrong. The Mugen Train arc shouldn’t have occurred yet.

Furthermore, it should have been Rengoku Kyojuro, not Shinobu, who went to confront the demon.

‘Ah…’

A moment of reflection revealed the reason.

It was my fault. My relentless demon hunting had decimated the local demon population, freeing up Shinobu.

With no local demons to hunt, she had been assigned to the Mugen Train mission.

The Demon Slayer Corps was perpetually short-staffed; they couldn’t afford to leave a Hashira idle.

My oversight.

I should have anticipated this and taken precautions.

But now wasn’t the time for regrets.

I would address that after rescuing Shinobu.

I thanked Aoi for the information and dashed off, utilizing the Demonic Sword Technique.

To save Shinobu.

‘Please, don’t let me be too late…’

Kocho Shinobu sat on the Mugen Train, following the Demon Slayer Corps’ orders.

‘I smell it. The scent of a demon…’

She sensed a demonic presence.

Fortunately, it didn’t seem particularly strong.

‘Let’s dispose of it quickly and return.’

Shinobu stood up.

She opened a window, slipped outside, and stood atop the moving train.

‘There it is.’

Had she arrived even slightly later, this demon would have been troublesome. It had merged with the train.

Given more time, it would have assimilated the entire train, turning it into its domain.

Fortunately, she had arrived early enough; it seemed to control only about 30% of the train cars.

“Show yourself.”

Shinobu heightened her senses. While the demon wasn’t powerful, complacency was a dangerous thing.

When the demon didn’t appear, she prepared to attack.

“Then I have no choice.”

Just as she was about to strike, the demon emerged from the train.

“Oh dear… Such an impatient human. You couldn’t even wait a moment~?”

Shinobu’s vigilance intensified, ready to kill at any moment.

“Do demons even understand romance~? Especially demons desperate for Muzan’s blood.”

“Heh… If you intended to anger me, you’ve succeeded~ I haven’t been this irritated in a while.”

The demon’s expression hardened.

‘Lower Moon One. Lower Moons are weak, as expected.

Even the strongest Lower Moon is this weak.

The real threat must be the Upper Moons.’

Shinobu identified the demon as Lower Moon One from the numeral etched on its eye.

“Prepare to die.”

“Heh… And what if I refuse~?”

“Sometimes, we must do things we don’t want to.”

Shinobu assumed a stance and inhaled.

To unleash her Insect Breathing.

[Insect Breathing Dance of the Butterfly Caprice]

Shinobu leaped, moving like a dancing butterfly, her poison-coated blade flashing as she repeatedly stabbed Enmu.

“Eh?”

Enmu’s eyes widened in surprise at her speed, but it was impossible for a Lower Moon to match her.

Unable to react, Enmu was struck multiple times.

‘Where’s the neck?’

Enmu had assumed death was imminent.

However, realizing his head was still attached, he looked at Shinobu and understood. Her blade wasn’t designed to decapitate.

‘I can win this~’

Confident of victory, Enmu spoke, “Too bad~ you can’t sever a demon’s neck… Gahk!”

He began to speak confidently, but before he could finish, Shinobu’s poison took effect.

“Wh-What…!”

Enmu collapsed. Shinobu smiled.

“You shouldn’t assume you’re safe just because your neck isn’t severed.”

Enmu couldn’t hear her.

The poison had already claimed his life.

“Oh~ He’s already dead!”

The tension drained from Shinobu’s body.

‘That wasn’t difficult. Now, I need to collect the body and return to the mansion.

Everyone must be waiting…’

For some reason, the person who came to mind wasn’t Aoi or Kanao, but him.

‘Have I grown attached to him?’

As she pondered, a voice called out from behind.

“Hmm. Interesting.”

Startled, Shinobu turned to see the numerals etched on his eye.

‘Upper Moon Three!’

Akaza made an offer, “I have a proposition. Why don’t you become a demon?”

Shinobu didn’t respond.

It was a worthless offer.

Annoyed by her silence, Akaza scratched his neck.

“Ha. I offer you a gift, and you ignore me.

I haven’t felt this insulted in a long time.”

He lowered his hand, saying, “Just go to sleep.”

‘Here it comes!’

Shinobu prepared her strongest technique.

‘Eh? My stomach?’

The difference in their strength was insurmountable.

Before she could react, Akaza’s hand pierced her abdomen.

“Gah…”

“Too bad. If you weren’t a Hashira, I would have spared you.”

‘Faster!’

I was sprinting, utilizing the Demonic Sword Technique for speed.

Using it like this would deplete my strength upon arrival, but…

‘Just stay alive, Shinobu.’

That was all that mattered.

For her sake, this hardship was nothing.

After what felt like an eternity, I saw her.

‘She’s alive.’

Relief washed over me. Had she died, I wouldn’t have been able to forgive myself.

I called out, “Shinobu!”

I hoped she would turn and smile, but my wish went unfulfilled.

She collapsed.

Thud

‘Ah…’

I fell to my knees. Her abdomen was a gaping wound.

“Aaah!”

I screamed, tears streaming down my face.

I had failed to protect her.

“Hmm? And who are you..? You seem rather strong. How about you become a demon?”

What kind of Demonic God was I, unable to protect even those closest to me?

Was there such a thing as a powerless Demonic God? No.

‘I’m not worthy…’

As despair consumed me, Akaza spoke, “Hmm. Another silent one? Fine.”

He stepped on Shinobu’s head, grinding it into the ground.

“You’re quite beautiful, even if your skills are lacking.”

“Get away from her.”

“Hmm…? What was that?”

“Get your filthy foot off of her!”

[Conditions met. Awakening Demonic Divine Art.]

I slowly rose to my feet.

As I stood, I spoke to him, “Kneel.”

[Demonic Divine Art Demonic Overlord’s Stride ]