The morning air in Busan hung thick and heavy, laced with the sharp bite of sea salt and the endless roar of the industrial city. To most people, that roar sounded like progress. To Kang Joon-seok, it felt like another weight pressing down on his chest, threatening to crush him before the day had even begun.
Ring… Ring… Ring…
The alarm shrieked through the thin walls of their cramped apartment, ripping him from sleep. 9:00 AM.
"Dammit! Not again!" Joon-seok hissed, flinging his worn-out pillow across the room. His joints groaned like rusted hinges as he rolled out of bed. At eighteen he should have been in his prime, but years of scraping by in low-rank dungeons and back-breaking construction work had left him with the battered body of a man twice his age—shoulders knotted, hands calloused, every muscle already aching.
He splashed cold water on his face, took a freezing shower that shocked his system awake, and yanked on the only clean hunter clothes he owned. In the tiny kitchen, his mother, Han Soo-jin, stood at the stove, stirring porridge with tired, mechanical movements.
"Mom! I told you to wake me earlier!" he snapped, grabbing a piece of dry toast.
She didn't turn around. "I called you three times, Joon-seok. You're pushing yourself too hard."
"You're just saying that because your brain's E-grade, like your rank," a mocking voice chimed in from behind him.
His sixteen-year-old sister, Kang Seo-yeon, leaned against the doorframe in her crisp school uniform, eyes sparkling with that familiar mix of teasing and worry.
"Eat your toast and mind your own business," Joon-seok barked, shoving the bread into his mouth.
Seo-yeon's expression softened. "Did you look at the book I left on your desk? The one about growth and mindset?"
"Seo-yeon, I barely have time to breathe between dungeon raids and the construction site," he muttered, avoiding her eyes.
The landline shrilled. Joon-seok snatched it up. The voice on the other end was cold and grim. He handed the phone to his mother without a word. Her face drained of color as she listened.
"Mom, I have to go," he said quickly. "I'll be back late."
As he ran toward the portal site, bitterness churned in his chest. My name is Kang Joon-seok. Rank: E. The lowest of the low. High-rankers lived like gods. He was dirt beneath their boots. His father had vanished years ago, leaving behind nothing but debt and a broken family. To keep Seo-yeon in school, he had traded his own future for a cheap sword he could barely keep sharp.
At the construction site gate, the foreman reeked of cheap tobacco and contempt. "Joon-seok! You're late again! The party's already gearing up! Get in there before I dock your pay!"
Joon-seok bowed low, hiding the fire in his eyes. "I'm sorry, sir. It won't happen again."
If I were an S-Rank… he thought bitterly. If I were strong, this man would be the one bowing. But dreams didn't pay the bills.
Inside the E-rank portal, the air reeked of damp stone and old shadows, stagnant like a recently disturbed tomb.
"Listen up, everyone!" Park Min-ho called out, the party's only D-rank and undisputed leader. His longsword gleamed under the flickering magical lanterns as he scanned the tunnel ahead.
Jung Soo-bin, the massive tank, adjusted his heavy shield with a reassuring nod toward Joon-seok. Behind him stood Lee Tae-sik, the nervous mage, fingers already twitching with sparks of fire. Choi Hyun-woo, the meticulous archer, tested his bowstring in silence. Han Ji-hoon lingered in the shadows, a ghost of a man, while healer Kim Ji-eun gripped her staff so tightly her knuckles turned white.
And then there was Joon-seok—the melee fighter with cheap gear and the lowest survival rate in the group.
A piercing screech split the air.
Skreeeee!
A dozen goblins lunged from the darkness, eyes glowing like hot coals, rusted axes swinging wildly.
"Formation!" Min-ho roared.
Chaos exploded. Fireballs lit the tunnel in orange bursts. Arrows whistled past Joon-seok's ear. Screams and the wet smack of steel meeting flesh filled the air. One goblin broke through and swung straight at Joon-seok's skull. For a split second he froze, heart slamming against his ribs.
Clang!
Soo-bin's shield crashed into the axe, saving him by a hair's breadth. "Move, Joon-seok!"
Heart hammering, Joon-seok stabbed forward. Three frantic, clumsy strikes later the goblin finally crumpled. Green blood sprayed across his boots.
"Pathetic!" Min-ho taunted, decapitating two goblins in one fluid arc. "Why even bother showing up if you're just going to freeze?"
Shame burned through Joon-seok like acid. Before he could answer, another blade slashed across his flank. White-hot pain flared.
"Stay still!" Ji-eun rushed forward. Soft healing light poured from her hands, knitting the wound with gentle warmth. She gave him a small, worried smile. "You're okay. We've got you."
The last goblin fell. The party pushed forward until the corridor ended at a pair of towering stone doors. The moment Min-ho shoved them open, the world tilted violently.
Blinding blue light swallowed everything. When it faded, they stood inside a cathedral of obsidian that stretched infinitely into darkness. Black pillars rose like the ribs of some ancient beast.
"This… isn't E-Rank," Min-ho whispered, voice cracking. "Hidden SSS-Rank Dungeon."
Above them, on a throne carved from bone and draped in celestial robes, sat a towering figure. A smooth mask covered its face—no eyes, no mouth, no expression. Power rolled off it in invisible waves.
"Welcome, insects," the voice boomed directly inside their heads, vibrating through their bones.
Crushing pressure slammed down. Joon-seok's knees buckled. Everyone crashed to the ground, lungs burning, unable to draw breath. Ji-eun sobbed, "Please… let us go…"
Joon-seok's vision flickered. A single blue interface sparked behind his eyes for a microsecond and vanished.
"My General is hungry," the Masked Being intoned. "Offer a sacrifice… or all of you perish."
A knight in black void-like armor materialized from swirling darkness, blade bleeding shadows. Without a word, the General blurred forward. Lee Tae-sik's head separated from his shoulders in a clean, silent arc. Blood hit the obsidian floor with a sickening patter.
Soo-bin tried to raise his shield. The black blade sliced through metal and man alike. The tank's body crumpled.
Min-ho screamed.
"Decide," the Masked Being commanded, voice calm and merciless. "One more head… or all of you die."
Min-ho's face was bone-white. "I'll go. It's my responsibility as leader."
"No," Joon-seok said. His legs shook so badly he could barely stand, but a strange, cold clarity settled over him. "I'm the weakest. If I die, the rest of you can survive. You all have people waiting for you."
"Joon-seok, stop!" Ji-eun cried, reaching for his arm.
He gently pulled away and walked forward without looking back. In his mind he saw his mother's exhausted smile and Seo-yeon's hopeful eyes. I'm sorry, Seo-yeon. Looks like I won't be reading that book after all.
The General raised the blade. A flash of cold light—
Darkness swallowed Joon-seok whole.
Beep… Beep… Beep…
Fluorescent lights buzzed overhead. The sharp scent of antiseptic filled his nose. Joon-seok's eyes snapped open in a sterile hospital room. His hand flew to his throat. No wound. No blood. Just the steady, strangely powerful rhythm of his own heartbeat.
"I'm… alive?" he whispered.
The door clicked open. A man stepped inside, radiating an aura so suffocating and predatory that the air itself seemed to thicken.
"Kang Joon-seok," he said quietly. "I am Kim Tae-jun, from the Hunter Association's S-Rank Bureau. We need to talk about what happened in that hidden dungeon."
Joon-seok didn't answer. His eyes were locked on the glowing blue screen hovering in the air in front of him, visible to no one else.
[Hidden Quest Completed: 'The Mortal Who Survived']
SYSTEM INTEGRATION: 100%
Character Status: Kang Joon-seok
Level: 1 → 5
Health: 100 → 150
Strength: 10 → 25
Speed: 8 → 20
Endurance: 12 → 30
Reflexes: 10 → 22
Focus: 5 → 18
New Skill Unlocked: "Survivor's Instinct"
• Automatically reacts to lethal threats.
• Grants short-term combat advantage.
[Claim Rewards] [Ignore]