Darkness.
But it wasn't empty.
When Kaito opened his eyes, he wasn't in the Archive chamber anymore. He stood in an endless expanse of shifting shadows, a mirror-world painted in black and silver. Shapes moved at the edges of his vision—tendrils, whispers, faint flickers of figures that dissolved as soon as he looked at them.
The Void.
It was like stepping into the heartbeat of the thing inside him.
Kaito Renge… you've come at last.
The voice wasn't a voice. It was inside him, resonating in his bones. It was both familiar and alien, like an echo of his own thoughts distorted into something else.
He spun around. "Who's there?!"
The darkness rippled. From it emerged a massive silhouette, towering and formless, its edges constantly shifting. In the center of its "face" was a single glowing eye—white, unblinking, ancient.
I am what you carry, it said. I am the first vow that was broken.
Kaito froze. "…The first?"
The entity stepped closer. Each movement sent shockwaves through the void-realm, fracturing the space around it into jagged shards of memory.
Before your Academy existed… before vows tamed Seiki… there was only hunger. The world's first wielder of Seiki sought power without restraint. They made a promise to never stop consuming. That promise became me.
Images flashed around Kaito—cities burning, oceans boiling, sky torn apart by tendrils of black energy.
I am the Kurai Seiki, the entity continued. The shadow of all vows. The Bearers like you are fragments of that original sin, chosen to carry what remains.
Kaito staggered back. "Chosen… by what? Why me?"
The eye blinked slowly. Because the world needs a vessel. To remember. To repeat.
Then the darkness shifted into a vision.
The Future That Shouldn't Be
Kaito stood on the Academy grounds—but it was ruined. The sky was torn open, raining black fire. Shadows writhed like living creatures, devouring everything in their path.
In the center of the chaos stood… himself.
But not himself.
This version of Kaito was taller, more monstrous. His entire body was covered in writhing tendrils of Void energy, his eyes blank white voids. His vow had completely shattered, and now he was nothing but hunger incarnate.
Behind him, Hina lay unconscious, her aura extinguished. Riku's threads hung broken like lifeless strings.
And Rei… Rei stood on the edge, watching silently, his expression unreadable.
The monstrous Kaito turned slowly toward the real Kaito, grinning with a mouth of fanged tendrils.
"This is you when your vow breaks. This is what you will become."
Kaito fell to his knees, trembling. "No… I won't let that happen!"
The monstrous version laughed—a low, hollow sound.
"You already feel it. Every time you use the Void, you're closer to me. And when the Academy betrays you—when they take everything—you will stop holding back."
The vision shattered into a million shards of black glass, leaving only the entity's glowing eye again.
You cannot escape me, Kaito Renge. The vow only delays the inevitable. But there is a way to choose how it ends.
Kaito gritted his teeth. "What way?"
The entity's tendrils unfurled, revealing a faintly glowing sigil—an unfamiliar Yakusoku.
Forge a new vow. A vow of your own making, not the one they taught you. Only then can you change the path. But doing so will cost you something precious.
Before Kaito could ask what it meant, the void-realm began collapsing inward, pulling him toward the eye.
Decide, Bearer. Will you delay the hunger… or embrace it?
And then—
The Pull Back
"Kaito! WAKE UP!"
Hina's voice ripped through the darkness like a lifeline.
Suddenly he was back in the Archive chamber, gasping for breath. The crystal still pulsed with faint light, but now it was cracked—fractured from the inside.
Hina knelt next to him, gripping his shoulders. "Hey! Stay with me!"
Riku stood nearby, sweat on his brow, his threads still anchoring Kaito's body to the floor. "He was almost gone. Another few seconds and the Void would've claimed him completely."
Rei leaned against the wall, arms crossed. His blue eyes were sharp but calm. "He saw it, didn't he?"
Kaito blinked, still trying to steady his breath. "…Saw what?"
Rei stepped closer. "The future. The truth of the Bearers."
Kaito's hands shook. "…I saw… me. But not me. A monster. Everyone… dead."
Hina's fists clenched. "What are you talking about? You're not a monster, Kaito. Don't let it mess with your head."
But Rei shook his head slowly. "The Void doesn't lie. It shows the path that awaits if your vow fails. That's why Bearers like us are dangerous—we are walking disasters waiting to happen."
Riku frowned. "So the Academy… keeps Bearers here to control them?"
Rei's expression darkened. "Control? No. They're trying to harvest us. To understand the Void and turn it into a weapon. That's why the disappearances happen. The ones who collapse—they're not 'sealed' to protect the Academy. They're studied."
Hina's eyes widened in horror. "You mean the students—"
"—are experiments," Rei finished.
The room went silent.
Kaito stared at the cracked crystal, feeling the faint whisper of the Void still curling in his mind. "Then… what do we do?"
Rei crouched down, meeting his gaze.
"We survive long enough to reach the core of the Undercroft. There's something deeper, beyond the Academy's control. A remnant of the first Bearer. If we can find it, we might learn how to break free from the cycle."
Hina nodded slowly. "Then we go deeper."
But Riku hesitated. "Deeper means more traps. More trials. The Academy might notice we're missing."
Rei smirked faintly. "They already know. They're probably watching us right now."
Almost on cue, the room shook violently. The remaining chains around the crystal snapped, and the walls began shifting again—this time sealing off exits.
"They're trying to lock us in," Riku realized.
Rei stood, his aura flaring. "Then we move. Now."
The Second Descent
They raced through the Archive as it collapsed, dodging falling debris and unstable glyphs. The path ahead twisted, revealing a new staircase spiraling even further underground.
Hina glanced at Kaito as they ran. "Are you sure you can keep it together?"
Kaito clenched his fists, the Void still stirring inside him but restrained. "…I have to."
As they descended, the air grew colder. The architecture changed—less like the Academy's stonework and more… organic. Veins of black crystal pulsed along the walls, faintly glowing like a heartbeat.
"This isn't the Academy's doing," Riku murmured, analyzing the structures. "This is older. Ancient."
Rei nodded grimly. "We're leaving the Academy's domain now. This is the real Undercroft."
The staircase ended at a massive black door covered in shifting sigils that almost seemed alive.
As they approached, the sigils rearranged into words:
ONLY THE TRUE BEARER MAY ENTER. THE REST SHALL PERISH.
Kaito froze. "…Just me?"
Rei looked at him steadily. "This part is yours alone. If anyone else steps through, they'll be erased."
Hina grabbed Kaito's arm. "No. We're not leaving you to walk into some death trap alone!"
But Kaito gave her a faint smile. "You said I'm not a monster, right? Then I need to prove it. I'll come back."
Riku's gaze was sharp but resigned. "We'll wait here. Don't take too long."
Rei leaned against the wall. "You're about to see the First Bearer. Don't let it break you."
Kaito took a deep breath, placing his hand on the living door.
It opened silently, swallowing him into darkness.
Inside the Hollow Crown
Beyond the door was a vast, cathedral-like chamber. Floating at its center was a massive throne carved from black crystal, and upon it sat a figure cloaked in shadows, unmoving, its face obscured.
The air was heavy, filled with the weight of ages.
The figure spoke without moving.
"You came. Another bearer. Another pawn."
Kaito stepped forward cautiously. "Are you… the First Bearer?"
A low, hollow chuckle echoed through the chamber.
"I was once called that. I was the one who made the first vow. And I was the one who broke it."
The figure slowly raised its head, revealing empty sockets where eyes should be.
"I am the end of your path, Kaito Renge. Unless you choose differently."
Kaito's breath caught. "Then tell me how. Tell me how to break this cycle."
The First Bearer extended a skeletal hand, pointing to the ground. A glowing sigil appeared—unlike any Yakusoku he had ever seen.
"Forge a vow not of restraint, but of purpose. But know this—when you do, you will lose something precious. A piece of yourself… or someone you love."
Kaito stared at the sigil, his heart pounding. Could he really change his fate?
Before he could decide, the entire chamber shook violently, cracks splintering through the throne room.
The First Bearer's voice grew distant.
"Hurry. Your time is running out…"
And then—
The floor collapsed.
Kaito fell.