Kang Joon-Seo lived in a small, cramped apartment that looked like it hadn't seen life in years. The wallpaper was peeling in some corners, the air smelled faintly of mildew, and the sink in the kitchenette always leaked. Still, it was quiet. That was the one thing he could be grateful for—no gunfire, no yelling, no explosions. Just quiet.
He limped inside, shutting the door with his shoulder. His left leg, the one patched together with metal, gave a small throb of protest. He ignored it. Pain had long since become part of the background. His coat—old, worn, with one torn sleeve—slid off his shoulders and dropped onto a folding chair by the wall.
Forty-five years old.
Former black ops soldier.
Retired because his body couldn't keep up.
His country gave him a medal, a handshake, and just enough pension to survive. Barely. No company wanted to hire a man who walked with a limp and carried secrets buried deeper than the grave. His name was flagged in too many government files. He was a liability.
Joon-Seo's gaze drifted to the small table in the corner. A single photo frame sat on it. He made his way over, step by dragging step, and picked it up.
The photo was a little faded now. In it, seven people—him and his squad—stood shoulder to shoulder, laughing like idiots. Someone had just cracked a bad joke. His second-in-command was mid-pose, throwing up a peace sign and pulling a stupid face.
Joon-Seo's fingers brushed over his face. The others… they were gone.
They had followed him into a mission they never should've taken.
He should've known. Should've seen the trap.
But he was too confident. Too blind.
And he lived.
Only him.
The coward, the broken one.
Even now, every night, he heard their voices. Sometimes, when the room went too quiet, he could hear the final radio call. Screams. Static.
He sat down, slowly. His joints cracked. His back ached.
There was a notebook on the table. An old, beat-up thing with fraying edges and scuffed corners. His vice-leader had written it—his squad's youngest, the one with the bright grin and stupid dream of becoming a novelist.
"You're wasting time," Joon-Seo had told him once. "No one's gonna read that."
The kid had just grinned. "It's okay. I just wanna leave something behind, you know?"
He had left it behind
He'd also left his life, following a man like him into hell.
Joon-Seo opened the notebook. He'd read it a hundred times. Maybe more. It was a messy manuscript about a noble family with a broken heir, old grudges, and ancient secrets. Nothing about it was perfect. But there was something honest in the way the kid had written it hiding in the lines.
Tonight, he got as far as the scene where the main character, Michael Lancaster, is told he's no longer needed by his family.
Joon-Seo didn't feel like reading past that.
He leaned back against the thin mattress of his fold-up bed and sighed. The ceiling above him was cracked in one corner. He closed his eyes. The pain in his leg had dulled. For a second, it felt almost…
Soft.
Too soft.
His brow furrowed
This mattress had never been soft.
Something was wrong.
The room smelled different. The air didn't feel damp anymore. It smelled clean. Too clean. Like soap and sunlight.
Then came the sound.
Footsteps.
Soft.
Too soft.
The kind of steps that never meant anything good.
Joon-Seo's eyes snapped open. His instincts screamed. He sat up—or tried to—and reached for the first thing within reach: a pen.
The steps were getting closer.
He didn't call out. Didn't ask who it was.
He aimed.
The pen sliced through the air and struck skin. A shallow wound bloomed on someone's neck.
"...!"
The man didn't cry out.
Instead, he blinked in surprise.
He was tall, dressed in black with a silver trim. A strange uniform. Formal. His gloves were leather, his posture perfect, and his eyes—
Cold.
But calm.
The man touched his neck. A drop of blood welled up on his glove.
"Young master," he said gently, "did you have a nightmare?"
Joon-Seo froze.
His breathing slowed, but his mind raced.
The man's voice was even. His words polite. But there was something in the way he moved—his body screamed training, discipline, danger.
He wasn't just some servant.
He was an assassin.
A high-level one.
And Joon-Seo recognized him.
From the manuscript.
This wasn't possible.
The man took a step back and moved to the window. He opened the curtains. Morning sunlight poured in, warm and golden. The room was nothing like Joon-Seo's.
The floor was polished wood. The walls were lined with soft green wallpaper. There was a wardrobe carved with roses and vines. Silk sheets. Embroidered pillows.
A noble's bedroom.
The man spoke again, carefully adjusting the curtains. "The Duchess and young master Allen are waiting in the dining hall. Shall I help you dress?"
Joon-Seo still hadn't said a word.
His heart beat in his throat.
He stared at the man again. Pale hair. Cold eyes. That soft, formal way of speaking.
Kain.
Kain Vante.
A side character in the manuscript. A member of the Vante assassin clan. The personal butler of House Lancaster. Silent. Deadly. Loyal to a fault.
And this man just called him—
"Young master."
Young master?
His body felt wrong.
The weight. The strength. Even his breathing.
And when he stood up, there was no pain in his legs.
He walked—walked—toward a standing mirror.
The face that stared back at him didn't belong to Kang Joon-Seo.
It was the face of a boy.
Seventeen. Dark hair. Light eyes. Thin face. Pale skin.
Michael Lancaster.
The forgotten heir of Duke Lancaster. The villain character in a manuscript never published.
The boy who was neglected by his father, hated by his half-brother, and isolated by everyone in the house.
Michael was a failure in everyone's eyes. The son of a mad princess. The useless noble who was eventually stripped of his name and sent away. He died off-screen. Meaningless.
And now—
Now he was Michael.
Kang Joon-Seo sat back down on the bed.
His hands trembled.
"What the hell is this…?"
Kain, who had remained silently respectful by the window, tilted his head. "Is the young master not feeling well? Shall I call the physician?"
"No," Joon-Seo muttered.
His voice came out wrong.
Softer. Higher.
Michael's voice.
"No need. I'm just… tired."
"Very well."
Kain didn't press.
Of course he didn't
He was trained not to.
Joon-Seo rubbed his face. His heart pounded in his chest, not from fear, but from confusion.
What happened?
He was in his apartment. He was reading. Then he fell asleep and…
He woke up here.
In a world written by a dead friend
In the body of a character destined to fade.
"…This isn't a dream, is it?" he whispered.
Kain gave him a look. Calm. Unreadable. "No, young master."
Joon-Seo almost laughed.
But it came out as a hollow sound.
It wasn't a dream.
Somehow—maybe by fate, maybe by punishment, maybe by guilt—he had ended up here. In the place that lived inside his vice-leader's imagination. In the world of dukes and swords and ancient curses. The world the kid wanted to escape to.
He looked around the room again.
This was the body of Michael Lancaster.
But Kang Joon-Seo wasn't a scared little boy.
He had lived through worse.
He had seen hell and dragged himself back out.
"…Damnit," he muttered, under his breath. "What kind of stupid setup is this?"
Kain, now folding a coat over his arm, said politely, "Pardon?"
"Nothing," Joon-Seo replied, shaking his head.
"As you wish, young master."
And just like that, the last soldier took his first step into a world of fiction.
Only this time, he wasn't just surviving.
And if this was the world from that manuscript… then Michael Lancaster was supposed to die.
Unless he rewrote the ending.
*****
It had been two days since Kang Joon-Seo woke up in this unfamiliar world.
Well, not exactly unfamiliar.
Everything here—the room, the servants, the ornate corridors, the smell of imported tea and waxed wooden floors—it all came from the manuscript he'd read again and again on lonely nights. The unfinished story written by his vice leader, Lee Hyun, the youngest in their squad. That wide-eyed kid who once told him, "Captain, one day I'll write a novel about this world. A world where people like us could be happy."
Joon-Seo didn't remember much about dying. Maybe he hadn't. Maybe his brain finally gave up. But here he was, not in his cramped apartment, but in the softest bed he'd ever cursed at.
And here he was, now known as Michael Lancaster.
He hadn't seen that assassin—butler, Kain, again. Thank God.
That guy was the living definition of dangerous. Sharp gaze, silent steps, and that weird mixture of elegance and violence that told Joon-Seo he had definitely killed before. Kain had only come because the Duke ordered him to "check on the first son." Apparently, Duke Lancaster still knew he had an eldest son. Surprise, surprise.
Since then, no one came. No breakfast summons. No concerned knock. Nothing.
Not that Joon-Seo expected more.
He wasn't loved in his past life. Why should things change in this one?
He sat near the window, the light filtering in through thick velvet curtains, casting gold onto the rich carpet. Outside, the garden stretched with surgical perfection—roses trimmed like military formations, fountains bubbling too politely.
Too clean. Too distant.
Just like the people in this house.
Michael Lancaster, as far as Joon-Seo recalled, was born to Princess Althea, a royal with more pride than sense, and too much power. She'd gone mad not long after childbirth, consumed by jealousy toward the maid—Allen's mother—who later became the Duchess.
Althea had harassed the woman to the edge of death. Then she herself crumbled.
Rumors said she laughed while smashing the nursery glass with her bare hands.
She died not long after.
And so, Michael became a stain. A burden. A walking reminder of a scandal that no one wanted to remember.
Joon-Seo leaned back in the chair and rubbed his eyes. "Michael" had grown up alone in this cold mansion, surrounded by wealth but starved of warmth. Even now, no one bothered to visit him.
He had to admit: it suited him. Quiet, empty days. No orders. No one expecting anything from him.
But that couldn't last.
Because he knew where this story was headed.
He remembered the original novel. Hyun had been proud of it—fantasy mixed with post-modern elements, like magic-powered trains, enchanted phones, surveillance systems fueled by mana. The world had advanced, but the noble titles and imperial lineages still held power. Power over economy, magic, and influence.
And at the center of it all was Allen Lancaster—Michael's younger brother.
The golden boy. The Chosen One. The protagonist.
Talented, handsome, righteous. A student of the prestigious Arcadia Academy, where nobles, geniuses, and future rulers trained. Allen had the typical hero trajectory: survive early challenges, build a loyal circle of comrades (and a growing harem, of course), defeat demon invasions, and save the Empire from destruction.
Michael? He was never really a villain. Just a background character. A reminder of pain.
But somewhere in the middle of the story… something happened.
Michael snapped.
He got possessed by a fragment of a demon's will. Brainwashed, manipulated—he attempted to poison the Duchess. Allen's mother.
Allen had no choice. The scene was written with emotional flair. The younger brother kills the elder, not with hatred, but sorrow. "Forgive me," Allen said, blade piercing through Michael's chest as blood dyed the marble floor.
Michael Lancaster died, forgotten.
"Tragic," Joon-Seo muttered, lips dry.
In the story, they were born only three months apart—Michael in March, Allen in July. Same year. Same blood. But one was abandoned, the other adored.
All because one had "no talent."
Or maybe, because no one bothered to look for it.
Joon-Seo lay back down on the bed, arms folded beneath his head, staring up at the high ceiling. "So I'm him now. The extra. The cursed son."
His voice echoed slightly in the silence.
He closed his eyes.
If fate insisted on giving him a second life… then fine. He'd live it on his terms. No plans to be a hero. No interest in glory or revenge.
He would survive. Quietly. Efficiently.
And if he could make some passive income along the way, even better.
But fate had other ideas.
Without warning, a bright ding rang out in his ears.
[ SYSTEM SYNCHRONIZATION COMPLETE.Initiating Host Compatibility Optimization.Adjusting Physical Condition to Optimal Parameters.Estimated Pain Level: High.Process begins in 3… 2… 1—]
"Wait—what the hell do you mean, pa—?!"
Then came the pain.
White-hot agony tore through his nerves like he was being ripped apart and stitched back together. His bones cracked and realigned. His spine stretched, his scars burned. Every injury from his old life, every limitation from his ruined body—
Erased. Remade.
He screamed.
But the room stayed silent.
The system didn't care. It was rewriting his body like code, like a machine upgrading its shell.
And then—
Darkness.