Three days passed quietly.
Jinwoo spent few days with jin-ah and now he plan to use the s rank key.
Tonight, he stood alone in his room.
Jinwoo took a slow breath and opened the System panel.
"…Use item."
[Demon Castle Dungeon Key – Activated]
The space before him warped.
A massive door of black stone materialized, towering far above him. Ancient symbols glowed faintly red across its surface, pulsing like a living heartbeat.
A new window appeared.
[Demon Castle]
Structure: Tower-Type Dungeon
Total Floors: 100
Jinwoo's eyes narrowed.
"…One hundred floors."
This wasn't a dungeon.
It was a like a world.
built to test limits.
He reached out and placed his hand against the door.
The moment it opened—
Heat rushed out like a furnace blast.
Jinwoo stepped inside.
The first floor was hell.
A vast chamber stretched endlessly in every direction, its ground cracked and burning. Rivers of molten fire flowed through the stone like veins, lighting the cavern in a crimson glow.
Then—
BOOM.
Something massive landed in front of him.
The ground shattered.
Jinwoo's heart skipped.
Before him stood a beast straight from nightmares.
Three enormous heads.
Burning red eyes.
Fangs longer than swords, dripping molten saliva.
Flames danced across its obsidian-black fur.
A name appeared in blue light.
[Hell Gatekeeper: Cerberus]
Rank: A
Type: Demon Beast
Jinwoo's breath tightened.
"…An A-Rank."
This was no illusion.
This was a true high-tier beast.
For the first time in a long while—
Fear crawled into Jinwoo's chest.
His instincts screamed.
Run.
His legs trembled slightly under the pressure pouring off the monster. Each breath Cerberus took sent waves of heat crashing against him.
If this were the old him—
He'd already be dead.
Jinwoo clenched his fists.
"…But I can't turn back."
Not now.
Not when everything he'd done led him here.
This dungeon was mean to test his will and strength.
It was meant to measure him.
To show him—
Where he stood.
How strong he truly was.
Steel-Fang slid into his hand.
Jinwoo raised his head, eyes steady despite the fear.
"Come on," he said quietly. "Let's find out."
Cerberus roared.
The sound alone shook the entire floor.
Flames erupted as the beast charged.
Jinwoo moved.
Far away—
Across the sea.
Inside a high-rise office in Eagle Country, the atmosphere was suffocating.
Hwang Dongsoo stood near the window, massive frame tense with restrained fury.
In his hand—
Reports.
Names.
Sung Jinwoo
Yoo Jinho
His eyes scanned the pages again and again.
Then—
CRRRSH.
The papers tore in half.
And again.
And again.
Dongsoo's teeth ground together.
"…Dongsuk."
The name left his mouth like a curse.
His older brother was dead.
Killed in a dungeon.
And these two nobodies—
Were the only ones who walked out alive.
Dongsoo slammed his fist against the glass.
The reinforced window cracked.
"Run," he growled softly. "Hide."
A slow, vicious smile crept across his face.
"When I return," he continued, voice trembling with rage,
"I'll tear you apart."
The room trembled under his killing intent.
Back in Korea—
A man was fighting with beast so massive in size.
The moment Cerberus charged—
Hell exploded.
Flames roared from its three mouths, merging into a tidal wave of fire that swallowed the battlefield. The heat was suffocating, blistering Jinwoo's skin instantly.
He leapt back, barely avoiding the inferno as the ground behind him melted into magma.
"…Too fast," Jinwoo muttered, teeth clenched.
Cerberus didn't stop.
Its massive body crashed forward, claws slamming into the ground with enough force to shatter stone. Shockwaves rippled outward.
Jinwoo was sent flying.
He rolled across the scorched floor, pain ripping through his ribs as he slammed into a pillar. His vision blurred.
So this is an A-Rank…
Before he could stand, one of Cerberus's heads snapped toward him.
Jinwoo activated Sense Enhancement.
The world slowed.
He saw the neck muscles tighten.
He dove aside.
CRUNCH.
Fangs closed where his head had been a second earlier.
Jinwoo sprang up and slashed.
Steel-Fang bit into the beast's hide—
—and sparks flew.
"…What?"
The blade barely pierced its skin.
Cerberus roared, all three heads screaming in unison. The sound battered Jinwoo's senses like a hammer.
Its tail swept across the floor.
Jinwoo crossed his arms just in time—
BAM.
He was smashed into the air like a rag doll.
Bones screamed.
He hit the ground hard, coughing blood.
For the first time since awakening—
Jinwoo felt it clearly.
I might die here.
Cerberus stalked toward him, flames dripping from its jaws.
Jinwoo forced himself up, legs shaking.
"…Not yet."
He pulled a High-Grade Health Potion and drank it mid-motion.
Warmth exploded through his body, shattered bones knitting back together painfully fast.
He rushed forward instead of retreating.
Cerberus lunged.
Jinwoo slid under its body, slashing at its legs again and again. Each strike carved shallow wounds—insignificant alone, but stacking.
The beast howled.
A claw came down.
Jinwoo raised his dagger—
CRACK.
The impact sent him skidding backward, arms numb.
Cerberus didn't let up.
Fire erupted point-blank.
Jinwoo crossed his arms, body engulfed in flames.
Pain tore through him.
His HP plummeted.
Alarms blared in his vision.
[WARNING: HP CRITICAL]
Jinwoo screamed—not in fear, but defiance.
He drank another potion and charged through the fire.
Cerberus recoiled, shocked.
Jinwoo leapt, stabbing into its left head's eye.
The beast shrieked.
Flames exploded wildly as it thrashed, smashing Jinwoo into the ground again and again.
He felt something break.
Darkness crept in.
Is this my limit…?
Then—
Jin-ah's face flashed in his mind.
The promise he made.
Jinwoo's eyes snapped open.
"No," he growled.
"Not here."
He forced himself upright as Cerberus prepared another inferno.
This time—
Jinwoo ran straight at it.
At the last second, he jumped, landed on its snout, and sprinted up its massive skull.
He drove Steel-Fang down with everything he had.
Once.
Twice.
Again.
Cracks spread across the beast's head.
Cerberus howled as one head collapsed, dissolving into black flames.
But the other two remained.
Enraged.
The monster entered a frenzy.
Its speed doubled.
Attacks rained down like a storm.
Jinwoo dodged what he could.
Blocked what he couldn't.
Every hit chipped away at him.
But he didn't stop.
Minutes felt like hours.
Blood soaked the battlefield—his and the beast's.
Finally—
Cerberus reared back, gathering all its remaining flames into a single attack.
Jinwoo felt it.
If that hits—I die.
He gathered everything.
Strength.
Agility.
Sense.
His body moved beyond exhaustion.
Time slowed to a crawl.
As the flames erupted—
Jinwoo vanished.
He appeared beneath the beast, driving his dagger up through its chest.
Straight into its core.
The world froze.
Cerberus's eyes widened.
A sound echoed as the core shattered.
The flames died.
The massive body collapsed, dissolving into ash and shadow.
Silence.
Then—
Jinwoo dropped to one knee, gasping.
His entire body trembled.
He laughed weakly.
"…I won."
Blue light flooded the chamber.
[Boss Defeated: Hell Gatekeeper Cerberus]
Clear Condition Achieved
[Level Up!]
[Level Up!]
[Level Up!]
Level: 24 → 27
[Reward Acquired]
• Demon Castle Floor 2 Access
• High-Grade Demon Essence
• Stat Points +15
Jinwoo pushed himself to his feet.
Every muscle screamed.
But he was standing.
He looked up toward the staircase leading higher into the tower.
One hundred floors.
He had cleared the first.
Jinwoo wiped the blood from his mouth and smiled faintly.
"So this is where I stand."
Jinwoo stood alone in front of the shattered floor.
The ashes of Cerberus scattered like black snow at his feet.
He exhaled slowly.
"…So even the first floor is like this."
His hands were still trembling—not from fear anymore, but from exhaustion. Every muscle in his body screamed as the adrenaline drained away.
In his previous life—
No, in the memories he carried—
He remember how jinwoo defeat it thinking that he can defeat it easier than now, he gain this knowledge but reality give him a slap, that knowing and doing are both different things.
But remembering about it and standing here himself were two completely different things.
Cerberus had pushed him to the edge.
because he weaker than him—
"If I'd been careless even once…" he murmured.
He wouldn't be standing here.
Jinwoo looked toward the staircase leading upward.
One hundred floors huh.
If a gatekeeper on the first floor could nearly kill him, then climbing higher now would be reckless—suicidal, even.
This dungeon was not easy as he throught it was.
But was hunting ground that scaled with him.
A place to become more stronger .
Jinwoo clenched his fist.
"When I get stronger," he said quietly, "I'll come back."
And when he did—
He wouldn't struggle like this.
He wouldn't scrape by on potions and stubbornness.
He would clear it cleanly.
Efficiently.
As a hunter should.
Jinwoo turned away from the staircase and headed back toward the exit portal, his steps slow but steady.
He had gained strength today.
But more importantly—
He had gained clarity.
There were still heights he couldn't reach yet.
And that was fine.
Because Sung Jinwoo was no longer in a hurry.
He would climb it slowly.