The scent hit him first.
Iron. Thick, cloying, suffocating.
Ren's breath caught in his throat as he skidded to a halt at the gates of his family's estate. The grand wooden doors, once pristine and imposing, hung crooked on their hinges, splintered as though some monstrous force had torn through them without effort. The lanterns that usually illuminated the path had been shattered, their oil spilled like black blood across the stones.
And then—the bodies.
Servants. Guards. Torn apart. Limbs bent at unnatural angles, faces frozen in expressions of pure terror. Some were missing entire halves of their torsos, as if something had taken a single, ravenous bite. Others were little more than red smears against the walls.
Ren's stomach lurched. His fingers trembled at his sides.
No. No, no, no—
He forced himself forward, his sandals slipping on the slick cobblestones. His pulse roared in his ears, a frantic drumbeat of denial.
"Father?" His voice was hoarse, barely more than a whisper. Then louder, desperate. "Mother?! Haru?! Suki?!"
Silence.
The main hall was a slaughterhouse. The tatami mats were soaked through with blood, the shoji screens shredded, their delicate paintings marred by crimson handprints. The ancestral swords mounted on the wall—prized heirlooms, symbols of his family's legacy—lay broken, their blades snapped like twigs.
And then he saw them.
His father lay sprawled near the dais, his chest caved in, his eyes wide and unseeing. His mother was beside him, her kimono drenched, one arm outstretched as if she had tried to shield the others in her final moments.
Ren's knees buckled.
He barely made it to the courtyard before his stomach revolted, bile burning his throat as he retched onto the stones. His vision blurred, his breath coming in ragged gasps.
"This isn't happening. This can't be happening."
But it was.
His family was gone.
The world spun. Grief, rage, horror—they crashed into him like a tidal wave, threatening to drag him under. He wanted to scream. To collapse. To wake up and find this was all some twisted nightmare.
And then—
A sound.
Faint. Choked.
A whimper.
Ren's head snapped up.
"Suki"
His youngest sister's name tore from his lips before he could stop it. He was moving before he could think, stumbling through the wreckage toward the inner chambers.
The door to the family shrine was ajar.
Inside, the air was thick with the stench of blood and something else—something cold, something wrong.
And there, in the center of the room, stood a man.
No.
Not a man.
A thing.
Tall, elegant, clad in a suit of deep crimson and black, his posture relaxed, almost bored. His fingers—long, pale, tipped with nails like claws—were wrapped around Suki's throat, lifting her effortlessly off the ground. Her small hands clawed at his grip, her face turning blue, her legs kicking weakly.
Ren's blood turned to ice.
Muzan kibutsuji.
The name echoed in his mind like a death knell. The Demon King. The monster from legends, from nightmares.
And he was here.
Muzan's slit-pupiled eyes flicked toward Ren, his lips curling into a smile too wide, too sharp.
"Ah," he murmured, his voice smooth, almost melodic. "The eldest son.
How… fortunate."
Ren's body moved before his mind could catch up.
His wooden sword—the one he had trained with for years, the one his father had scoffed at—was in his hands in an instant. He lunged, his scream raw with fury.
Muzan didn't even flinch.
He sidestepped the strike with inhuman grace, his movements fluid, effortless. Ren pivoted, slashing again, aiming for the demon's throat.
Muzan caught the blade between two fingers.
And snapped it like a dry twig.
Ren barely had time to register the shock before Muzan's other hand lashed out, backhanding him with enough force to send him crashing through a low table. Wood splintered. Pain exploded across his ribs.
"Pathetic," Muzan sighed, tilting his head. "And here I thought the heir of this house might be worth my time."
Ren gritted his teeth, forcing himself up. His vision swam, but he refused to look away.
Suki gasped, her tiny fingers still struggling against Muzan's grip.
"Let her go."
Ren charged again.
This time, he didn't swing blindly. He feinted left, then twisted, aiming a kick at Muzan's knee. The demon's eyebrow arched—amused—before he simply stepped back, letting Ren's foot whistle through empty air.
Then, with a flick of his wrist, Muzan released Suki.
She crumpled to the floor, coughing, her small body shuddering as she gulped in air.
Ren's relief lasted half a second.
Muzan's hand shot toward him, fingers outstretched, aiming to impale him through the chest—
—and then, like lightning, Ren saw it.
A flash. A fraction of a second. The trajectory of the attack, the angle, the inevitable impact.
His body moved on instinct.
He twisted, narrowly avoiding the strike, Muzan's claws grazing his side instead of piercing his heart.
The demon paused.
His eyes gleamed with something like interest.
"Oh?"
Ren didn't wait. He grabbed a shard of his broken sword and slashed upward, aiming for Muzan's throat.
Muzan caught his wrist.
And squeezed.
Bones cracked. Ren's scream tore through the room.
"Fascinating," Muzan murmured, leaning in close. His breath was cold against Ren's ear. "That intuition of yours… it's almost like hers."
Ren didn't understand. Didn't care. He thrashed, his free hand clawing at Muzan's face.
The demon sighed.
Then, with a single, effortless motion, he slammed Ren into the floor.
The world went white.
When Ren's vision cleared, he was on his back, his body screaming in protest. Muzan loomed over him, his expression unreadable.
"You amuse me," the demon mused. "A human with a spark of something… more."
Ren spat blood. "Go to hell."
Muzan chuckled. Then, without warning, his nail elongated, sharpening into a blade-like point.
He slashed his own wrist.
Dark, viscous blood welled up, dripping onto Ren's chest.
The moment it touched his skin, the pain began.
It was like fire. Like acid. Like every nerve in his body had been set alight. Ren arched off the ground, his scream ripping from his throat as the demon's blood seeped into his wounds, into his veins.
His vision darkened at the edges. His muscles convulsed.
"What's happening to me*?!"*
Muzan stepped back, watching with detached curiosity.
"Let's see what you become," he murmured.
Ren's body twisted. His bones cracked, his skin burning as something changed inside him. The hunger came next—a gnawing, all-consuming void in his gut, worse than anything he had ever felt.
His gaze snapped to the corner of the room.
To Suki.
She was curled into herself, her tiny frame trembling, her tear-streaked face pale with terror.
"Nii…san…?" she whispered.
Ren's mouth watered.
No.
He tried to fight it. Tried to claw back control. But the hunger was too strong, the demon blood rewriting him from the inside out.
His body moved on its own.
Suki scrambled back, her breath hitching. "Nii-san, please—!"
Muzan's laughter was a soft, delighted hum in the background.
Ren's fingers twitched.
Then he pounced.
Her screams were the last thing he heard before the world dissolved into red.