The sky had yet to fully darken, but the twilight seemed reluctant to linger. Clouds moved faster than usual, as if the wind above was in a hurry to deliver a message from far away. Beneath the temple where Itsuki lived, the stone corridors once walked by ancient monks trembled softly—not from an earthquake, but from something awakening.
That night, Itsuki descended alone.
Reina and Akito were still in the North, investigating the appearance of the robed entity. But Itsuki couldn't wait. Something within the temple had been calling to him ever since the nightmares began.
The underground corridor was narrow and cold, its moss-covered walls carved with ancient symbols that emitted a faint golden glow. He followed that light. His footsteps were nearly silent, but his heartbeat thundered in his chest.
At the end of the passage, he discovered a chamber he had never seen before.
In its center stood a stone circle. Within it, faded ancient symbols formed a pattern, and in the middle of those symbols stood a mirror—tall, human-sized, its frame made of metal that hadn't rusted despite the dust.
Itsuki stepped closer.
The mirror… did not reflect him. Instead, it revealed something else. A forest, thick with mist… and a woman in a white robe standing beneath an old tree. Her face was unclear, but her eyes—her eyes seemed to gaze directly into him.
"Mother…" he whispered, before he could stop himself.
As if in response, the image moved. The woman raised her hand—not in warning, but pointing. Behind her. Into the darkness within the mirror.
Itsuki held his breath. Behind the woman, tall figures began to emerge. Vague. Faceless. They were not spirits. But neither were they human.
The mirror trembled.
Then cracked.
A fine line ran across it from end to end, and a whisper, soft as wind through leaves, echoed from the stone walls:
"She sees you."
Itsuki stepped back once, but didn't turn away. He knew—if he fled now, he would never find this place again. And he would never learn who—or what—he had truly inherited.
He reached out and placed his hand on the cracked surface.
For a moment, he felt cold… then heat… then emptiness.
Then a voice—older than any spirit—spoke directly into his soul:
"The true heir is not born to fight. He is born to choose who will remain… and who must be forgotten."
Itsuki staggered back, pulling his hand away.
The mirror went dark. Its reflection returned to dull, lifeless stone.
But the message lingered.
This wasn't about war. It was about choice. About who deserved to be carried into the world to come… and who would be left among the shadows.
He began to climb back to the surface, slowly.
Night had fallen. The wind had died.
And in the distance, the old temple bell rang once—though no one had struck it.
Something had been released. And now, the world waited to see whether the heir was ready… or if he would become the final shard that shattered it all.
—
The air above ground felt heavier when Itsuki emerged from the underground corridor. The night sky seemed to absorb the last of the light, leaving only ash-colored clouds drifting slowly above the temple roof. No birds. Not even crickets.
He crossed the stone courtyard, his mind still echoing with the voice he had heard. The words—about choosing who would remain—haunted him more than any threat he had ever faced.
He paused at the stone steps leading to the main hall.
A shadow stood there.
Someone waited beneath the lantern light. Slim build, head slightly bowed. A gray hood concealed their face, but something in their posture made Itsuki instantly wary. He hadn't sensed this figure's presence—no footsteps, no spiritual energy.
"You're not a spirit," Itsuki said softly. "And you're not a normal human."
The figure raised their head.
Their eyes were empty. Not blind—just absent of life.
"I am… what's left," they said.
The voice was flat, weightless, as though speaking between two dreams that had never met.
"Left of what?" Itsuki asked, his hand drifting to the hilt of his sword.
"Of the world you abandoned. Of the choices you never made."
The figure stepped closer, light as a shadow. But each step seemed to bend the air around them, as if reality itself rejected their presence.
"I did not come to kill you," they continued. "But to warn you."
Itsuki remained silent. Waiting.
"The Fourth Gate… was not made for spirits. Or humans. But for something this world has forgotten." The blank eyes stared into him. "And the Nameless Walkers… are only the beginning."
A wind blew from the back of the temple, carrying the scent of metal and scorched earth.
"If you wish to save this world again," the figure said, "you must break the chain that binds you to your old blood. Or you will become the final key they need."
Itsuki opened his mouth to ask who they were—but in that instant, the wind surged, and the figure faded like morning fog.
Gone. Without a trace. Alone once more in the cold courtyard, though he knew—he wasn't truly alone.
And this time, the enemy might not be something outside.
But something growing within him.
The heir to power does not simply inherit. He is tested—proven worthy, or not.
And that night, for the first time in a long while, Itsuki felt fear.
Not of the strength his enemy held…
But of the doubt blooming in his own soul.
Deep below, behind the cracked mirror, other eyes began to open.
Not all were human. Not all wished for the world to be saved.
Some… only wanted to watch it burn.
—
Dawn had yet to fully rise, but pale mist hung among the trees that surrounded the temple. Itsuki hadn't moved from where he stood since the figure vanished. His eyes stared at the stone floor, but his mind wandered deep through the meaning behind those haunting words.
"The Fourth Gate…"
He had never heard of such a thing. The first three spirit gates had shaken the world enough. But this—this felt older. Wilder. Not a prison. Perhaps… an origin.
Fast footsteps approached. Reina.
"There you are," she said, breathless. "We were looking—"
She stopped, catching the look in his eyes.
"You saw something?" she asked, more softly now.
Itsuki nodded. "Someone. Not a spirit. Not human, either."
"They spoke to you?" Reina asked.
"Not… exactly. It was more like… they forced their thoughts into mine."
Reina stiffened. "That's an old technique. Only creatures from before the spirits were shaped ever used that. Before this world had form."
"He called himself 'what's left,'" Itsuki said. "He said I must break my bloodline's chain. Or I'd become the key to the Fourth Gate."
Reina fell silent for a long moment. "The Fourth Gate… there's no record of it. But I've seen its symbol. Beneath the ruins in the South—where the old guardians performed their sacrifice rituals."
Itsuki looked at her. "If there's a gate even spirits won't speak of, why hide it?"
"Because maybe it wasn't built to connect worlds," Reina said, eyes lifting toward the sun breaking through the mist, "but to separate them."
And if that was true—then someone… or something… was trying to reverse it.
Suddenly, footsteps rushed in from the east side of the temple. Akito appeared, carrying an old, dusty scroll.
"You need to see this," he said, unrolling it on the stone altar.
Old red ink formed faded images. But clearly, there were four circles—three connected by lines, and one isolated. Unlinked. Unjoined.
"We found this in the ruins of Shokan, where the first spirits descended," Akito explained. "The Fourth Gate was never opened. But… it was never sealed either."
Reina touched the fourth symbol. A tremble ran through her fingertips.
"If it was never sealed… then something may have always been waiting behind it."
Itsuki stared at the symbol.
He understood.
This journey wasn't just a battle against enemies.
It would be a descent into forgotten history—truths even spirits had hidden.
And if that gate truly opened…
The world would no longer be split in two.
It would break—between what is real, and what was never meant to exist.
—
Elsewhere, beneath ruins long buried by snow, voices whispered among forgotten stones:
"Open the gate, blood-heir. Open… and return us all."
The temple bell rang three times—soft, but its echoes lingered long in the wet morning air. That bell was once used to summon guardian spirits. But today, no spirit answered.
Only silence.
Echoing like a call down a bottomless well.
Itsuki, Reina, and Akito stood over the ancient scroll. The air around them began to change—heavier. Colder. Akito whispered, "We shouldn't speak the name of the gate too often. The world listens."
Suddenly, the stones around the altar trembled. Not from an earthquake—but as if something beneath the earth tried to speak—knocking from beneath the skin of the world.
From a thin crack beneath the altar, dark mist seeped out. Not smoke—but shadow turned liquid.
Reina stepped back. "This isn't spirit energy. This… is the memory of the world."
Itsuki crouched, touched the crack.
And in an instant—his eyes went wide.
—
A Vision:
He stood in a world without sky or ground. Just an ocean of broken mirrors, each one reflecting a version of himself—angry, despairing, bloodthirsty, weeping, laughing madly.
In the center of the space stood a gate. Not made of stone or wood—but bone. Massive. Ancient. Alive. It pulsed like a living heart.
Beyond the gate, whispers—thousands of them—merged into a desperate roar.
"We wait… We are the remnants. The forsaken. Let us return through your blood…"
Suddenly, one of the mirror-versions of Itsuki turned to face him. Same face—but eyes pure black.
"If you open that gate… you will become us."
—
Itsuki gasped, flung backward. Reina caught him just in time.
"What did you see?" she demanded.
Itsuki panted. "There's something beneath this temple. Not just stone or earth. But a path to the Fourth Gate. Like a wound hidden in the body of the world."
Akito clenched his fists. "If that path is real… we need to seal it before something breaks through from the other side."
But before they could move, the stone floor before the altar cracked.
From the fissure… a hand emerged. Pale. Thin. Like a corpse—but moving. Clutching the altar's edge.
Then a voice rose from the deep—not a scream, not a whisper—but a chant. Monotone. Ancient. Like a prayer from a creature that had forgotten how to die:
"Blood gate, forgotten door,
Heir, open it.
Let the world be whole again,
Through the wound that never healed…"
Reina drew her sword. Akito prepared a spell. But Itsuki… stood frozen, hearing the melody—strangely familiar. He had never heard it before in his life. And that… was the most terrifying part.