The great hall.
Date Terumune or rather, the will controlling this shell, sat at the head, unmoving. His lapis pupils were locked dead onto the gray-robed figure at the doorway. A voice, like the resonant fluttering of moth wings, squeezed from his throat.
"Demon God of the Kantō, Nakai Shinji… I know of you. To rise from a nameless lesser demon to your current state in such a short time, you are truly extraordinary. But I cannot discern your origin."
"Your actions are also more decisive than I expected."
Unhurried. Unruffled.
As though the one who had been raging moments ago was not him at all.
Shinji did not immediately draw his blade, nor immediately strike. He stood at the entrance of the great hall. His crimson demon eyes swept over the scattered map flags, then over the still-bleeding corpse of the messenger upon the tatami.
"You're quite efficient at killing your own men."
The corner of Terumune's mouth twisted.
"They are merely tools. When one breaks, replace it. The greatest advantage of the human race is their numbers, their breeding speed, and their obedience. Use them up, then make more. My father failed to understand this, and so he was defeated by that white dog. I will not make the same mistake."
Father. Defeated by that white dog—Tōga.
That, without a doubt, referred to Gaki no Maru.
And the one before him, was, without a doubt, the son who had inherited all of his father's demonic power and memories.
The daiyōkai, Menōmaru.
The human body he controlled.
Shinji took a step forward.
The floorboards creaked.
"Menōmaru—"
"Himemushimaru was a tentacle you sent into the Kantō. You absorbed his remnants, and thus learned of me. I know all of this. But what I want to know, is something else."
The golden ring within his crimson demon eyes rotated faintly.
"Who awakened you?"
Terumune's lapis pupils narrowed slightly.
His mouth did not open.
But the shift in his expression was itself an answer.
He had been struck.
This was also what puzzled Shinji.
He did not wish to ask about Kaguya, for the cooperation between Kaguya and Menōmaru was already known to both sides. And it had now, moreover, been declared bankrupt.
What puzzled him, was only this.
One had to understand: Tōga had sealed Menōmaru's father in the bitter, frozen north at least two hundred years ago.
A seal of that level could never have dissolved on its own.
For Menōmaru to have awakened and inherited his father's demonic power, there had to have been external intervention.
"…Your intelligence is not lacking either."
Terumune finally spoke, his pace somewhat slower than before.
"But do you think I will tell you?"
"You will."
Shinji took another step forward.
"Because you're stalling for time. Waiting for your true body to arrive, correct?"
Shinji stopped five paces from Terumune.
His crimson demon eyes stared directly at the thing writhing behind those lapis-colored pupils.
"From the depths of Mutsu to Kurokawa Castle, even with your full demonic power, it will take a quarter of an hour."
Five minutes.
Moth demons could fly, yes, but they had never been a race known for speed.
The corner of Terumune's mouth twitched.
He truly had been stalling.
Menōmaru's true body was coiled within the mountain valleys deep in Mutsu.
3000 kms of mountain ranges separated it from Kurokawa Castle.
Even for a daiyōkai, moving from awakening to arrival required time.
Thus, controlling Terumune to speak, to question, to stall, it was all to buy time.
To wait for his true body to descend and crush this arrogant invader upon his own territory.
However—
"Coincidentally."
Shinji's voice was without much inflection.
"I'm also stalling. So let's talk."
Menōmaru, controlling Date Terumune, narrowed his eyes.
Then, he smiled.
He had rarely met such an honest demon.
And he was also suddenly somewhat astonished.
"Then… let us talk."
He said.
"The existence that awakened me, you need not know the specifics. I can only tell you this: it is an existence older than my father. Before we crossed the sea from the continent, it had already lived upon these islands for a very, very long time. It loosened a corner of the seal. And I awakened through that gap. That is all."
Older than Gaki no Maru. Rooted in this land for over a thousand years.
Which meant…
"That one, is also from outside, then?"
Shinji asked.
This time, "Menōmaru" did not respond directly.
He merely continued speaking through the body of Date Terumune.
"Centuries ago, my father led his forces across the sea from the continent. At that time, the continent was no longer suitable for us. The human factions were too vast. The territories were too crowded. Every side was at war. And so he found this island.
"But he was intercepted in the Kansai by that white dog, the Lord of the Western Lands, Tōga. He was slain in a single battle. Utterly destroyed. His demonic power. His memories. All his unfulfilled ambitions, all of it was sealed beneath the northern ice by that one's blade.
"My father's corpse, and I along with it were sealed away."
Date Terumune's body rose.
The black kimono fell loosely.
Every joint in his body seemed to crackle and pop.
"I slept within the ice for centuries. Only recently was I awakened. I inherited everything from my father."
He stepped through the spreading pool of the messenger's blood without a care.
"Now that I have awakened, you can guess what I intend to do—"
"Fight from the east to the west. Crush the remnants of Tōga's forces."
Shinji finished the sentence for him.
Terumune stopped.
"You grasp things quickly."
"It's not hard to guess. You consolidated the six provinces of the northeast not to become a human general, demons have no interest in the thrones of men. What you want is to sweep south from Mutsu, through the Kantō, and into the Kansai."
Shinji leaned against the doorframe.
"To tread upon the territory that once belonged to Tōga. To reclaim what your father never obtained."
A flicker of surprise passed through Terumune's lapis pupils.
Then, his expression shifted.
He became serious.
"You are powerful, Demon God Nakai Shinji. But I can sense it, your demonic energy is close to that line, yet you are still one final step from standing alongside those like me."
"Though reaching this point is already remarkable, you are merely a lowly, insignificant race, yet you have achieved what the vast majority of demons could not accomplish in a thousand years."
"Still, that final step is not so easily taken."
"How many demons? How many battles? How many slaughters?"
"From ancient times to the present, no one knows how many named demons, demons with osore, have fallen in pursuit of that very step."
Terumune raised a hand and pointed out the window.
"But I can help you.
The six provinces of Mutsu. The entirety of Dewa. One million souls, I have them all in my grasp.
Their fear of demons. The ghost stories they pass from mouth to mouth. The osore they condense as they tremble in the dark of night—
If you are willing, I can push all of it onto you.
Combined with the osore of the million souls of the Kantō you already carry, the two combined could grant you, in a single night, a total volume of osore approaching that of a daiyōkai.
And then, come with me.
From east to west."
The osore of millions.
For any demon standing one step from the threshold, this was a temptation of fatal allure.
Osore was the weight of ghost stories told and remembered.
If millions feared a single name simultaneously, then the bearer of that name and a daiyōkai were separated only by a layer of paper.
Though still not a true daiyōkai.
But the outward difference between a daiyōkai and an ordinary demon was this: a daiyōkai could allow its own Truth to flow outward, devouring heaven and earth, achieving Phenomenon, and thereby gaining an incalculable total volume of demonic energy.
An ordinary demon's energy could only exist within itself.
With such an astronomical number of osore, the gap could, to a degree, be bridged.
However—
"I refuse."
Shinji's answer came without pause.
Without hesitation.
Terumune froze.
"…No? I am offering the osore of the entire northeast. Are you certain?"
"Certain."
"And your reason?"
The crimson demon eyes looked at Terumune, looked at the great moth, thousands of kms away, within that body.
"Because...."
Shinji uncrossed his arms.
His expression did not change.
His tone did not change.
But the words he spoke caused the temperature of the entire great hall to plummet.
"No foreign dynasty lasts a hundred years."
"—?!"
Terumune was stunned.
For a full two seconds.
Even the writhing within his lapis pupils stopped.
The buzzing resonance in his voice broke off entirely.
He understood.
Though it was the grammar of the continent, the meaning was crystal clear.
Across the sea, centuries ago, there had been a foreign dynasty that had fought from the grasslands to the Central Plains.
Its iron cavalry was invincible beneath heaven.
Yet for all its military might, it had not held the throne for even a hundred years.
Outsiders, upon another's land, could not sit securely.
But if the other's intent had merely been to express defiance, that would be one thing.
Yet his meaning was clearer still, he had seen through their origins.
Yes, the so-called Gaki no Maru, the so-called demonic army from the Heavenly Continent, in essence, had never truly been demons of the Heavenly Continent.
They had been the demonic vanguard that had crossed the sea to this land in the wake of that foreign dynasty's armies.
They were not true demons of the Heavenly Continent.
They came from the grasslands far to the north of the continent.
They could not hold that land.
They had merely, with great difficulty, stepped into it, and then been forced to retreat.
Because that land was far too chaotic.
Even with the Eternal Blue Sky behind the Yuan, they could not endure.
And in the end, they had been shattered there.
So Shinji would never submit.
"So that's how it is."
Terumune's smile faded.
The killing intent seeping through the control lines instantly filled the entire great hall.
The pure, destructive will belonging to the daiyōkai, Menōmaru.
"Since you refuse...."
"Then I have no choice but to kill you."
If he would not submit, then he was an enemy.
An obstacle upon his path of westward conquest.
And obstacles, naturally must be killed.
And at this moment—
"The time… is nearly up!"
The instant those words fell,
The entire sky darkened.
Starting from directly above Kurokawa Castle, golden scale-powder surged in from every direction like a sandstorm, covering every inch of the heavens in an exceedingly short span of time.
Shinji looked out from the side window of the tenshukaku.
Menōmaru's true body did not descend upon Kurokawa Castle.
Because it was too vast to descend at all.
It had already merged with the sky itself.
From the southwest of Mutsu extending north to Dewa.
Spreading east to Shimotsuke.
Touching south toward Nagato.
A pair of wings.
Spanning hundreds of kms.
Golden base patterns, covered in eye-shaped markings the size of castles.
Deep violet pupils rotated slowly within each "eye."
Beneath those wings, hundreds of moth demons wove through the canopy of scale-powder.
And at the center of those wings, two true compound eyes hung down from the summit of the clouds.
Each one dozens of meters in diameter.
Their lapis-colored pupils refracted a light identical to Date Terumune's own.
Magnified a thousandfold.
Gazing upon the entirety of Mutsu.
Gazing upon Kurokawa Castle.
Gazing upon him.
This, was unmistakably the Phenomenon of the daiyōkai, Menōmaru.
Illusion.
Moth demons were masters of illusion and control.
Menōmaru, having inherited the full demonic power of his father, had pushed this talent to its absolute extreme.
His illusion did not act upon any single person's five senses, it acted directly upon heaven and earth itself.
Using himself as the dome.
Using scale-powder as the canopy of the sky.
Shrouding the lands of several provinces beneath the wings of a single moth.
Within this illusion, his perception was everywhere.
His control was everywhere.
He was the sky.
Within the great hall, Date Terumune's body collapsed with a dull thud.
The control lines had been severed.
The puppet was no longer needed, because the true body had arrived.
The humming from the dome shook the very foundations of Kurokawa Castle.
The moth's wings beat.
Once.
It covered three provinces.
.
.
.
.
T/n: This refers to the history of the Mongols, the Yuan Dynasty, or the "Grassland", who conquered the "Heavenly Continent" (China), yet could not hold it for even a hundred years before being driven out.
For those who still don't understand, Shinji's meaning in direct way is:
"You outsiders (Mongols) sat on someone else's land (China) and still lost it in less than a century. You will not sit on this island (Japan) either. I will not join you."
Btw fanfic aside, Mongols irl couldn't invade Japan, Indonesia, India and Vietnam at all unlike China where they even ruled for 90 years.