The nest was breathing.
Not metaphorically — Kai could see the cursed energy compressing and expanding like lungs. At the end of the tunnel, the chamber glowed with a sickly red hue, lined with pulsing veins of spirit matter and warped symbols etched into the stone by claw or worse.
He stepped forward.
The cursed energy pressure increased with every footfall. His Six Eyes filtered the layers of incoming data automatically — heat differentials, cursed energy signatures, weak points in the walls. The sheer weight of the aura down here was suffocating. Any normal person would've passed out just from standing this close.
But Kai wasn't normal.
Not anymore.
He entered the core chamber.
The nest's center pulsed like a malformed heart suspended in midair. Thick, black cords of cursed flesh wrapped around rusted sewer piping. Around it, dozens of half-formed cursed spirits — some twitching, others shrieking, some too still to be called alive — clung to the walls like parasites.
And guarding it, embedded in the largest cursed mass, was the Core Spirit.
It looked like a corpse stitched together from shadows, metal, and rage. Its arms were layered in cursed armor, its face a broken porcelain mask with glowing red cracks. The entire room reeked of cursed development gone wrong — a creature that had consumed too much grief, too fast, and had grown sentient from it.
The Core Spirit's head twisted unnaturally to stare at him.
"…Satoru…" it hissed.
Kai's eyes narrowed. "Wrong timeline, pal."
The chamber erupted.
Cursed spikes launched from the walls.
Kai activated Blue, collapsing space around him and snapping the first wave mid-flight. He leapt, flipped forward, and launched a burst of cursed energy downward, creating an explosion to propel himself higher.
The Core Spirit lunged—quicker than anything he'd fought before.
It extended in every direction — arms twisting into spears, teeth reforming along its shoulders, a third eye glowing from its chest.
Kai blocked one strike with Blue Fang but was kicked backward by a tendril disguised as a floor pipe. He smashed into the chamber wall, gritting his teeth through the impact.
The Core followed.
Kai ducked under a wide slash, kicked upward into its ribcage, and released a focused burst of cursed energy from his foot. The spirit staggered.
He dashed in, stabbed for the heart—
—but the cursed energy bounced off.
It had a layered core.
Kai backed off immediately.
The Core Spirit laughed — a rattling, static-choked sound that felt like it was being played on a broken TV.
"You are incomplete."
Kai rolled his shoulder, tasting blood in his mouth.
"Not for long."
The battle escalated.
They clashed again — energy flaring, limbs colliding, explosions rippling through the chamber. Kai tried every trick he had — Blue, Red, enhanced movement, talisman traps — but the spirit adapted. Its limbs would snap off and regrow in new forms. It even began mimicking some of his cursed techniques in crude ways.
Kai was faster.
Smarter.
But he was still a kid.
And he was starting to lose ground.
After a brutal clash that ended with Kai being thrown across the chamber and nearly impaled by a cursed shard, he lay there — panting, body trembling. Blue Fang was shattered beside him. Blood dripped from his lip. His right arm was partially numb. The Reverse Cursed Technique earlier had helped, but he couldn't rely on it too often.
The Core Spirit stood tall above him now, gloating. Around them, the half-born cursed spirits stirred, drawn to the energy of the fight.
They were watching a predator stalk the last flicker of light in the dark.
Kai's vision flickered.
His Six Eyes strained.
Not because they were failing — but because they wanted more.
He closed his eyes.
And finally… he let go.
Suddenly, everything stopped.
His cursed energy snapped into perfect alignment.
No more hesitation. No more bottlenecks.
The Six Eyes didn't just activate — they merged with his natural perception.
He didn't look at cursed energy anymore. He understood it.
Every particle. Every fluctuation. Every intent.
His aura surged — not explosively, but precisely.
Balanced.
Focused.
His vision sharpened to atomic clarity. He saw the weak point in the Core Spirit's layered defenses — a thinned area exposed every time it expanded to absorb ambient fear.
He stood, slowly, calmly.
His body still hurt. But his eyes didn't blink.
And in that moment, the Core Spirit hesitated.
Kai spoke softly, but it echoed through the cursed chamber.
"Let me show you what it means… to be limitless."
He raised one trembling hand.
"Domain Expansion…"
The world shattered.
"…Unlimited Void."
The chamber vanished.
Everything vanished.
The Core Spirit froze, its fragmented intelligence overwhelmed in less than a second.
It now stood within Infinity itself.
The Domain wasn't huge — Kai's cursed energy wasn't yet vast enough for grandeur — but it was dense. Every thought, every twitch of intent, every cursed fluctuation was now forcibly analyzed by his target.
To a spirit, it was madness.
To Kai, it was silence.
He hovered in the center of the Domain, floating above nothingness.
Light surrounded him — soft, blue, endless.
The Core Spirit convulsed, clawing at itself.
"Too much… too much—!"
Kai closed his eyes.
He didn't even have to lift a finger.
The cursed spirit crumbled under the weight of perception.
Its body imploded in a wave of cursed matter.
The half-born cursed spirits died screaming as their connection to the Core was severed.
The nest collapsed.
When the Domain faded, Kai stood alone in the now-silent chamber.
Water dripped faintly somewhere far off.
Steam hissed from a broken pipe.
The Core Spirit's corpse was dust.
And in its place… peace.
He lowered his hand.
Then his legs buckled.
He stumbled out of the core chamber and back into the main tunnel, using the wall for support.
Every part of his body screamed. His brain was overclocked from the Domain. His cursed energy reserves were dangerously low. But he was alive.
He passed one of the talismans he had placed at the start of the fight.
It glowed gently as he walked by.
A signal of survival.
Near the tunnel's edge, he finally stopped.
His body leaned against the rusted frame of the sewer exit.
The early morning light was starting to break through cracks above.
He reached into his jacket and pulled out a strip of thick black cloth.
With trembling hands, he tied it around his eyes — the first blindfold.
Not to blind himself. Not to copy someone.
But to suppress the Six Eyes — now permanently active — and prevent cursed energy from leaking everywhere. It would also help him disappear into the background again.
He exhaled slowly as the world dimmed… but not to him.
He could still see everything.
Just quieter now.
Just hidden.
He staggered upward.
The talisman at the top glowed faintly.
He reached out…
And released the Curtain.
The barrier shattered silently.
A pulse of energy rippled outward across the Gotham underground.
Sensors lit up across the city.
Magical beacons flared.
Mystical radars screamed.
And above it all, unseen eyes turned toward the disturbance — too late to witness it.
Kai collapsed by the sewer's edge, unconscious, body steaming from overuse.
Blindfold secured.
Smiling faintly.