Lucivar Thornheart died a nobody.
No power. No fame. No family at his bedside. Just a flickering light above him, a broken body beneath him, and a sterile hospital room that smelled more like a waiting grave than a place of healing. Cancer, they said. Stage four. Terminal. Nineteen years old, already fading. His only real companions were the silence of night and the hum of the machines keeping him alive a little longer than nature intended. Every breath had been a struggle. Every blink a farewell. He had accepted it. Death, in its cold cruelty, had seemed a relief.
He thought that was the end. He was wrong.
He awoke to wind—cold, sharp, and alive. The sky above was no longer stained with city lights but blanketed in stars, a vast, unfamiliar canvas. The trees around him stood tall and ancient, their silhouettes cutting through the mist like watchful giants. The forest breathed with a quiet menace, and somewhere in the distance, something howled. Lucivar shot upright, gasping. He wasn't on a hospital bed. He wasn't in a hospital at all. His fingers gripped dirt. Real, rough earth. His skin was smooth. Healthy. He looked down at his arms, flexed his hands—there was strength. He could move. He could breathe. No tubes. No pain. No death.
"What… the hell?" he whispered.
He stood slowly, unsure if he was awake or trapped in some vivid afterlife. The forest loomed around him, quiet but not still. Somewhere nearby, a branch cracked, and a low rumble echoed through the trees like the growl of something ancient and hungry. He looked down at his clothes—simple black robes, a wooden sheath tied at his waist, though it was empty. There was no sword, no weapon, just the strange awareness that his body no longer felt like the one that had wasted away in a hospital bed. He had no memories of how he got here. No clues. But everything screamed one truth: this was not Earth.
With no other choice, he began walking. The forest stretched endlessly in every direction, trees twisted like claws and undergrowth thick enough to swallow paths whole. Time lost meaning. Minutes might have passed. Maybe hours. The moon above—deep red and disturbingly close—watched him like a hungry god. He pushed past low branches and muddy trails, his senses on high alert despite knowing they were utterly untrained. Then, through the mist and shadow, he saw it.
A corpse.
A man lay facedown in the dirt, blood pooled beneath him, soaking into the roots. His head had been crushed, his back torn open. Lucivar's breath caught. He froze, heart hammering. The sight was horrific, but more than that—it was real. The iron tang of blood hung heavy in the air. Something had done this. Recently. Viciously. He took a cautious step back.
And then—a sound.
Wet. Snarling. Close.
He turned his head, and the breath fled his lungs.
It stood nearly eight feet tall—humanoid in shape, but everything else was wrong. Its skin was too pale, stretched taut over unnatural muscles. Its eyes glowed a hungry yellow, and horns jutted from its forehead like broken tusks. Blood dripped from its jagged maw. Its smile was wide. Inhuman. Terrifying.
A demon.
Lucivar stumbled back, every instinct in his new body screaming. "Nope," he gasped. "Nope nope nope—"
The demon lunged.
He barely rolled away in time. The creature's claws sliced into a tree, bark flying like splinters. Lucivar scrambled backward, slipping on damp leaves, breath coming in terrified bursts. He had no training. No idea how to fight. He was just a dying kid from a hospital room—reborn into a nightmare with no tools to survive it.
The demon turned, grinning.
"Fresh," it hissed, its voice guttural and warped like it belonged to something that once had language but forgot how to be human. "So fresh."
It charged again.
Lucivar tripped. He fell hard, shoulder slamming into the ground beside the corpse.
His hand landed on something cold.
A blade.
Chipped. Dull. Broken at the base. But still a blade.
He didn't think. He didn't plan.
He just swung.
The metal met flesh with a sickening crunch, carving across the demon's neck with the force of pure panic. Blood—black and thick—erupted in a spray. The demon reeled back, howling, claws thrashing at empty air.
Lucivar's eyes were wide. He hadn't aimed. Hadn't even tried to fight. The blade had just struck where it needed to.
The demon gurgled, clawing weakly at the wound, stumbling like a drunk. Then, with a final twitch, it collapsed.
Dead.
Lucivar remained frozen, his chest heaving. His ears rang. His fingers trembled around the broken blade. He stared at the creature's body—massive, wrong, now lifeless. He had killed it. By accident. But still.
Killed it.
Him. A hospital ghost. A no-one.
"What the actual… hell is this place?"
The woods offered no answer.
Lucivar forced himself to his feet, legs shaking beneath him. He wiped the sweat from his brow and looked at the weapon in his hand. It was old, rusted near the hilt, soaked in a blood that didn't belong in any medical textbook. Still, it had saved him.
No. He had saved himself.
He looked down at his clothes again. The robes were foreign. Ancient. Something out of feudal Japan. No sign of electronics, no hint of modern civilization. Just sandals, a fraying belt, and dirt between his toes.
And a crimson moon above it all.
He stood in the middle of this foreign forest, body trembling—not with weakness, but with something else. Not power. Not yet. But… possibility. This wasn't Earth. That much was clear. But it wasn't just any fantasy world either. The monster, the outfit, the moon—it all pointed to something far more specific. A universe he had only ever read about.
Demon Slayer.
He swallowed hard.
Was he really in that world?
"But why me?" he whispered. "Why now?"
No answer.
But something shifted within him. A feeling. A flicker. A beginning.
And then it happened.
A soft chime, melodic and deep, echoed in the air. Not from the forest. Not from the trees. From nowhere—and everywhere.
A screen appeared.
Glowing faintly, translucent, floating mid-air like a ghost given shape. Words carved in glowing silver danced across it, perfectly still in the wind. Lucivar stared, lips parting.
[SYSTEM LOADED] – Welcome, Lucivar Thornheart. Your path begins here.
His breath caught. A slow, trembling smile curved his lips—not from joy, but awe. A system? In this world?
He didn't understand what was coming.
But whatever it was…
He was ready.