Standing a hundred meters away, the Demon King Muzan looked unimpressive to the Hashiras.
A neat, white suit.
A black, loosely donned, greatcoat.
Combined with the hat on his head, Muzan looked as if he had arrived here to attend a party — an exquisite, formal event.
If the dress wasn't enough to express that, then surely it was the small smile that appeared on his lips; it was the way he casually threw his hands inside his pants pockets; it was the way he walked out of the small, unimpressive crater he had created; it was the way he stopped… at the very edge of that crater, and opened his mouth… in a carefree manner.
"Give me the child, and I will let you live."
Silence.
A lone gust of wind rushed past between the Demon Slayers and Demons.
The full moon overhead dimmed, as if a black thundercloud had appeared at the horizon, casting its shadow from afar.
These words were something the Demon Slayers had expected to hear.
It was unknown at what point in time the Demon King had begun targeting Kai and Shinobu's child.
Kagaya Ubuyashiki, the leader of the Demon Slayer Corps, had made it clear that Muzan wanted nothing more than the ability to walk in the Sun. The ability to roam through the world during the day, just like he did during the night. The ability to let his terror reign from one corner of the world to another without being hindered by his one weakness — absolute death under sunlight.
And, so, the Demon Slayer Corps had expected Muzan to come for the Hashiras themselves.
It wasn't an unknown fact to the Demons that the Hashiras had undergone a strange kind of demonification, without experiencing the same sunlight-related restrictions.
However, Kai had also told the Demon Slayers that Muzan, by some incomprehensible means, knew that he couldn't just replicate the Hashiras' unique ability by getting his hands on them.
It didn't mean that he wouldn't come for the Hashiras, though.
But, somewhere between Shinobu conceiving the child and now, Muzan seemed to have become sure that in her and Kai's child lay all his answers. He had become so sure of it, in fact, that he had been willing to lay a stop to all demonic activities for months.
The Hashiras had remained on guard all this time, thinking about what the Demon King could be planning.
That he was planning for an all-out war…
The worst-case scenario seemed to have come true.
And, it seemed, Muzan wasn't even bothering to hide his true intentions.
That, in itself, said a lot of things — Muzan's unimpressive look was a facade; the Demon King didn't even feel the need to beat around the bush with the Hashiras — empowered, demonified Hashiras — on the other side; he… had made a move, knowing that he would win…
That's what Muzan meant by saying those words aloud.
That's what the Demon King meant by acting so carefree.
The lone gust of wind reappeared, this time from the other side.
"Amitabha…" Gyomei, the Stone Hashira, finally stepped forward in the same carefree manner as Muzan.
He wasn't alone, though.
All the Hashiras, who were lined up a step behind him, together stepped forward as well.
Then, together, the eight Hashiras reached for their weapons, unleashing the power hidden within them as they released their Shikai.
BOOM!
The combined Spiritual Pressure of the Hashiras became a tangible, spherical dome as it propagated forward.
It flattened all the wind.
It crushed all the sound.
The tangible, spherical dome of utter destruction reached Muzan in a fraction of a second.
It forced even him to hold onto his hat as he skidded a few steps back into the crater that he had just walked out of… smiling.
The wave didn't stop there, though.
It continued, on and on, and finally reached the filthy ocean of demons.
Bloody squelches overwhelmed the surroundings as the Spiritual Pressure disintegrated the demons.
A dozen…
Hundred…
Over a thousand…
In only a moment, the might of the Hashiras turned the vanguard of the demons into a literal filthy ocean of blood.
And, just as it seemed that the generational war between the Demon Slayers and Demons would end even before it could properly begin, the tangible wave of destruction met a wall.
A POP,like two bubbles bursting apart, resounded as the Hashiras' Spiritual Pressure ran right into a similarly powerful spherical dome.
The meeting of those two waves alone killed nearly a thousand demons, blood showering in all directions… almost as if laying down a red carpet.
"Haha…" Muzan chuckled. "… A show of might? Let me show you what true might is, Hashiras. Let me show it to you… without even lifting a finger…"
The red carpet of disintegrating blood created several gaps in the army of demons.
In those gaps, figures materialized just where the Hashiras' Spiritual Pressure had been neutralized.
Slowly, those figures began walking out of the darkness, letting the stunned full moon bring them to light.
The Moons of Demon King Muzan!
Rengoku's free hand clenched into a shaking fist, his eyes widening in utter surprise.
It wasn't just his, but all the Hashiras' faces underwent an extreme change, their emotions getting thrown into chaos by the sight in front of them.
Behind the Hashiras, the faces of Tanjiro, Kanao, and others instantly lost color, paling.
No.
It wasn't just because of the presence of the Moons.
With most of the Hashiras possessing their own Blood Demon Art, on top of their Bankai, they had stopped worrying about the Upper Moons long ago.
The thing that surprised them so much…
The sight that brought out extreme reactions from the Hashiras…
"Oi!" An Upper Moon walked out from the group, growling like a beast. "You… have someone that I want…"
It was Gyutaro — the long-dead Upper Moon Six… now donning the Kanji of Upper Moon Four in his eyes!
Before the reality of that unfathomable reality could settle in, suddenly, with a resounding BANG, a figure appeared between Gyomei and the other Hashiras… like a black-striped, white-skinned ghost.
"Where is he?" Akaza, the Upper Moon Three, asked. "Where is… Kai Stormborn?"