As for the second reason, it was to prevent the yokai from being exposed.
Both Hagoromo-Gitsune and Nurarihyon were top-class great yokai, to say nothing of the large number of subordinates under them. If they fought without restraint, the entirety of Kyoto would become a battlefield.
At that point, the existence of yokai would be exposed to all of Kyoto.
That was why Rowan had Serie and Medea create barriers around the entirety of Nijō Castle. It was not only to prevent Hagoromo-Gitsune and her people from escaping, but also to confine the battlefield to Nijō Castle.
This way, no matter how violently they fought inside, few people outside would notice.
Perfect.
Just as Rowan was praising his own plan, Nurarihyon's figure appeared in the sky above Nijō Castle.
His battle with Hagoromo-Gitsune erupted instantly.
At that moment, Nurarihyon's body miraculously regained its youth, returning to the appearance he had possessed in his prime. Surging, unrestrained yokai aura erupted from his body.
Driven by his yokai power, he had returned to his peak form.
Without question, he could not maintain this state for long, but it was more than enough to fight Hagoromo-Gitsune.
He held Nenekirimaru in his hand, its blade reflecting the moonlight and flowing with a cold, silvery radiance.
Then he swung.
There was no unnecessary name for the move.
It was simply a downward slash.
The path of Nenekirimaru transformed into a silver waterfall pouring down from the sky, splitting the night in two.
Wherever the blade light passed, space itself groaned under the strain. The air was sucked into a vacuum, only to be filled by even more violent yokai energy the next instant.
The Karamon Gate of Nijō Castle, an ornate structure that had witnessed three centuries of Tokugawa glory, was touched by the blade light.
Its golden decorations melted, its wood vaporized, and its roof tiles shattered.
The entire gatehouse was split cleanly down the middle. The cut surfaces were as smooth as mirrors before both halves collapsed inward with a thunderous crash.
However, Hagoromo-Gitsune was no longer there.
Her nine pitch-black fox tails spread behind her like a screen. Her figure flashed three times through the air, leaving a slowly fading black afterimage behind each time.
The light from Nenekirimaru brushed past her side, severing several strands of her flowing black hair. Before the hairs could even fall, the blade energy shredded them into powder.
"Old fool."
Hagoromo-Gitsune's voice sounded from every direction at once.
"After several centuries, you still haven't improved at all."
Her nine tails spread open behind her, each holding a different weapon.
The iron fan of the second tail.
The katana of the third tail.
The spear of the fourth tail.
The weapons came crashing toward Nurarihyon from every direction, their trails lingering in the air and weaving a net of death that covered the heavens.
Nurarihyon snorted coldly. With no intention of dodging, he swung his weapon and slashed without hesitation.
Boom!!!
The shockwave created when Nurarihyon's blade collided with Hagoromo-Gitsune's tails swept outward like a tsunami.
The eastern gate of Nijō Castle was directly torn from its foundations. Its pillars snapped into several pieces, tumbling through the air before crashing into the moat and sending water dozens of feet high.
In the courtyard between the first and second compounds, century-old black pines were ripped out by the roots. Broken branches and stones flew wildly through the gale.
Both were forced backward.
Nurarihyon drifted dozens of meters through the air. His feet created a series of ripple-like waves in the empty sky before he finally stabilized himself.
Blood seeped from the webbing between the thumb and index finger of his right hand, flowing down Nenekirimaru's hilt and dripping into the darkness in eerie crimson blossoms.
Hagoromo-Gitsune crashed heavily onto the roof of Ninomaru Palace, causing more than half of it to collapse beneath her.
Roof tiles shattered in a dense series of cracks, like heavy rain striking withered lotus leaves.
Her nine fox tails swayed behind her, each trembling faintly.
The two old enemies stared at one another across the distance, each seeing a trace of surprise in the other's eyes.
Several centuries had passed, and both had improved tremendously.
Yet neither had expected that they would still be unable to suppress the other.
That was seriously irritating.
While Hagoromo-Gitsune and Nurarihyon fought, their subordinates also clashed.
In an instant, the whole of Nijō Castle descended into chaos, with battlefields appearing everywhere.
Kubinashi faced Gashadokuro.
Gyūki fought Hakuzōsu.
Yuki-onna battled Kyōkotsu…
Even Nyanko-sensei transformed into his true form and charged freely through the mass of yokai, smashing aside countless enemies as he rushed toward Hagoromo-Gitsune.
He intended to join Nurarihyon in surrounding and attacking her.
"Don't even think about it!"
Hagoromo-Gitsune's loyal subordinate, the Mole Cricket Clan, tried to stop Nyanko-sensei from interfering in the battle between Hagoromo-Gitsune and Nurarihyon.
The two sides immediately began fighting.
"This is getting lively."
Meanwhile, Cú Chulainn saw the chaotic battlefield and immediately felt his blood boiling.
He loved scenes like this.
It felt as though he had returned to the past, to the days when he freely crossed battlefields.
"I'm going on ahead."
After leaving those words behind, Cú Chulainn leapt into the air and flew toward the battlefield.
At that moment, he resembled a streak of crimson light tearing through the night, dragging a tail as striking as fresh blood behind him.
Then he descended upon the battlefield.
Boom!!!
A deep impact rang out as the ground shook violently.
A shockwave spread outward from the point of impact, ripping up every stone slab in Nijō Castle's courtyard and sending fragments flying like cannonballs.
Within the dust, Cú Chulainn slowly stood, attracting the attention of countless yokai.
He wore a tight blue suit that outlined his lean, powerful physique. Dark-blue armor covered his shoulders, its silver metallic sheen flowing beneath the moonlight.
In his hand was a long spear as red as blood.
The demonic spear—Gáe Bolg!
Cú Chulainn spun the spear once in his hand. Its tip sliced through the air with a sharp whistle, and the corners of his mouth curled upward, revealing a row of pointed teeth.
"Let me join the fun."
As he spoke, his gaze had already locked onto Hagoromo-Gitsune's yokai subordinates emerging from the ruins.
The next instant, Cú Chulainn vanished from where he stood and appeared before a gigantic ōnyūdō as if he had teleported.
An ōnyūdō was a yokai with an enormous body. Even a smaller one stood over two meters tall, while the largest could embrace an entire mountain fortress in its arms.
The ōnyūdō before Cú Chulainn was one of the huge ones, standing more than ten meters tall.
Not only was it gigantic, but it also possessed astonishing brute strength.
However, before Cú Chulainn, it did not even have time to raise its weapon before the crimson spear pierced straight through its chest.
Immediately afterward, Cú Chulainn flicked his wrist and swept the spear upward.
The ōnyūdō's enormous body was lifted completely off the ground and then smashed viciously into the surrounding yokai, knocking down seven or eight lesser demons.
But that was only the beginning.
After bringing down the ōnyūdō, Cú Chulainn charged into Hagoromo-Gitsune's forces and began slaughtering them.
The long spear thrust, swept, chopped, and smashed in his hands, every movement wild and ferocious.
A crimson afterimage trailed behind him, and wherever he passed, yokai fell one after another.
A nure-onna lunged at him from the side while he appeared distracted. The snakes covering her head opened their mouths simultaneously and bit toward his neck.
But Cú Chulainn did not even turn around.
His spear spun, and the shaft swept horizontally.
Bang!
The nure-onna's head exploded into a cloud of blood.
Yet the deaths of these yokai did not frighten Hagoromo-Gitsune's subordinates.
Even more surged forward like a tide, attempting to bury Cú Chulainn beneath their numbers.
The principle that enough ants could bite an elephant to death was fully displayed by their charge.
Boom!!!
At that moment, another heavy object crashed into the ground.
This impact was deeper, duller, and heavier than Cú Chulainn's landing.
The walls of the inner compound seemed to be struck by an invisible giant hammer and exploded outward from the center.
Amid the flying debris, a massive, suffocating shadow slowly rose.
He stood over seven meters tall, like a small mountain.
His entire body was covered in knotted muscles, each one appearing as though it had been twisted together from steel cables. His skin was dark brown and covered in scars left by countless battles.
He was bare-chested, wearing only a battle skirt around his waist, and held an absurdly enormous stone axe in his hand. A dark-red glow flowed across its blade.
He did not speak.
He merely stood there and released a heavy breath that sounded like rock grinding against rock.
The great hero of Greek mythology—
Heracles had arrived.
After appearing, Heracles raised his axe-sword toward Hagoromo-Gitsune's subordinates.
Against this group of small fry, Heracles needed no technique and no strategy.
Every one of his attacks was simple.
A horizontal sweep.
The stone axe moved in his hands as though it weighed nothing.
With a casual sideways slash, a wave of force several meters long cut everything before him in half.
Walls, trees, and the yokai attempting to block him—everything was reduced to fragments beneath that terrifying brute strength.
Hagoromo-Gitsune's subordinates were as fragile as rotten wood before Heracles, each one shattered by a single swing of his axe.
The yokai's attacks struck his body without leaving even a white mark.
Whether claws or fangs, acid or curses, all they could do was scrape a few sparks from skin tempered by God Hand before fading away unwillingly.
With only a few swings of his axe, Heracles crushed every enemy in front of him into pieces.
Faced with the rampaging Heracles and Cú Chulainn, the yokai finally became afraid.
These monsters who had terrorized Kyoto for centuries and committed every kind of evil now retreated desperately like homeless dogs.
They had never faced enemies this powerful.
They seemed completely unbeatable.
In the past, humans had always feared them.
They had never imagined that today, they would be the ones fearing humans.
The natural order had been completely reversed.
But fear was like a tide.
Once it began spreading, there was no stopping it.
"Average. Average. Far too average!"
Cú Chulainn laughed loudly as he killed every yokai blocking his path.
"Isn't there a single powerful yokai here who can fight me? Weren't you planning to exterminate humanity? I'm right here! Come kill me! Hurry up and kill me!"
But faced with the increasingly crazed Cú Chulainn, the yokai only retreated again and again.
Not one dared step forward.
At this moment, Cú Chulainn was simply too terrifying, even more savage and frightening than the yokai themselves.
What did it mean for one man to hold a pass against ten thousand?
This was it.