The Weapon Genius: Anything I Hold Can Kill

「Shinkirō no Yaiba.」

The words left Mura’s mouth like the toll of a death knell, quiet yet resounding in the air of the crumbling cavern.

A blur.

A phantom slash surged forth.

The Demon’s four eyes narrowed, two on the face, two hidden just beneath the ridged crown of his skull. A horizontal strike? No. A trick. His instincts screamed it, and he responded with brutal precision. His black blade spun up to intercept the attack coming from his left, clanging steel against steel—

But nothing was there.

In that fraction of a heartbeat, in that false moment of defense, his body pivoted into an opening.

A shadow fell behind him.

Too late.

A clean SHHHTK! echoed as a sharp line of crimson bloomed across the Demon’s exposed flank.

"—Tch."

The strike had been aimed perfectly beneath his ribs, where the armor had just begun to part with his motion. The Demon vaulted backward, his boots cracking the stone beneath as he landed across the ruined field, a viscous stream of inky ichor trailing from his side.

He stared at Mura.

The samurai stood upright, slowly sheathing his blade halfway. His frame, colossal and broad like a living sculpture, glinted with sweat and menace under the dim glow of the broken cave. His white hair, tied back in a warrior’s tail, shifted ever so slightly in the breeze that leaked in through the new fissures in the cavern walls.

The Demon’s laughter rumbled low.

"Heh... That wasn’t bad."

The blood dripping from his wound hissed against the ground like venom. It wasn’t red. It was deeper. Denser. Alive in ways it shouldn’t be. From the gash, something like shadow leaked, a pulsing, tar-like darkness that didn’t belong in this world.

And then, his voice dropped an octave.

"...Analysis."

The world stilled.

In an instant, the Demon’s four eyes glowed—an eerie, bloodshot gold—and within his mind, every frame of that exchange replayed with terrifying clarity.

The stance... traditional Iaido. No, that step. A mislead. The hip motion suggested a wide slash, but his foot twisted outward mid-execution... shifting weight off the front leg...

The Demon’s thoughts moved like a cascade of daggers.

The illusion was never about the sword. It was in the momentum—he sold the motion through posture, breath, intention. Even the sound of his exhale was bait. And then—

He could still feel the cold steel sinking in.

—the true strike was delayed by only 0.3 seconds. A downward cut, tight arc, no wasted movement. It entered through my blind spot when I leaned into the bait.

The blood on his fingers pulsed again, like it resented being drawn.

"...’Shinkirō no Yaiba’... Hmph."

The Demon grinned, wide and jagged, his teeth lined with a black sheen of rot.

"You really are one of the last humans that can stand against me, aren’t you?"

Mura didn’t answer.

The cave groaned around them.

Chunks of rock had begun to fall, fragments of stalactites shattered from the impact of their movements. Steam hissed from the gouges left behind by their blades. The light from above grew stronger, an exit forming. Or perhaps the earth itself was too afraid to contain them much longer.

Then, without warning—

The Demon vanished.

A whisper.

And then a sonic BOOM as he reappeared behind Mura, dragging his obsidian sword in a rising diagonal slash.

「VOID REND」

The blade screeched against air, creating a vacuum line so sharp it split sound itself, shattering the nearby rock shelf into sand with its wake.

But Mura was already gone.

He spun low beneath it, footwork blurring into the terrain, using the broken debris as leverage. A single leap launched him skyward, his frame soaring like a cannonball of flesh and steel, before he came crashing down with a two-handed overhead strike.

The Demon met it.

Their blades clashed, but this time the ground gave out.

The cavern split.

A roar erupted from beneath as molten rock surged up from below, the clash of titans had cracked through to the subterranean magma vein. Fire belched up around them as they launched apart mid-air, flipping through falling rubble and plumes of volcanic smoke.

They landed outside, at the base of the mountain, amidst a collapsing forest now lit with ember and ash.

The Demon, now crouched low and licking his own blood from his claws, grinned wider.

"Good. Very good. I was getting bored of humans pretending to be warriors."

Mura adjusted his grip.

"Well, I’m not pretending."

His blade pointed forward again.

"I am the last sword of the East."

The demon’s grin widened beneath the lacquered smile carved into its mask, jagged teeth glinting from beneath. The torchlight warped again, shadows crawling across the cavern walls like hungry hands.

"Then die with your title intact."

It moved.

No fanfare, no flourish. Just motion—pure, uncut, and immediate. The kind of speed that didn’t follow rules. A blur that started in front of Mura and reformed behind him.

But Mura had already turned, katana dragging across the stone in a sharp backward arc.

CLANG—

The cave sang with metal.

Blade met blade mid-spin. Sparks leapt from the collision like fireflies fleeing the clash. Jin’s breath hitched. He couldn’t follow the exact movements anymore, not really. They moved too fast, too exact. The cave around them struggled to hold their presence, the air itself folding and warping with every motion.

The demon pressed forward. Its strikes weren’t strikes in the normal sense, they were slashes with weightless violence, dark edges that peeled light away, each swing drawing afterimages that threatened to cut deeper than the blade itself.

Mura stood his ground. His movements were disciplined. Grounded. But with every parry, the angle of his stance shifted subtly. Calculated corrections. Like he was mapping the future with every step, every inch of steel.

And then—

Eight shadows surged forward at once. The demon didn’t even seem to move, but its blade danced between each shadow, attacking from above, the side, the rear, even from the ground like a snake.

Mura narrowed his eyes.

"Shinsei Hōjin."

No swing. No counter. A single pivot of the wrist.

From that center, his sword spun into a blur of arcs, a dome of intersecting cuts, a full-circle defense.

The shadow strikes hit the dome all at once.

CRACK—CRACK—CRACK—

The sound wasn’t just impact. It was the sound of the cave protesting. The demon’s strikes were inhuman in force, somehow ancient, like they came from a time when monsters ruled without form.

But the technique held.

The moment passed. The dome dissipated into particles of air and steel memory.

The demon drifted back a few paces. Not out of necessity, more like curiosity. The jagged mouth under its mask curled, not in frustration, but something that tasted like delight.

"Ah... So even now, you haven’t forgotten your roots. You still cling to that school of sword saints. You really are the last."

Mura didn’t respond. His blade lowered a few inches; its tip aimed at the cave floor—but his posture never broke.

Then the demon’s grin stretched.

It raised its blade slightly, a hum of pressure leaking off its edge. And then, with no ceremony, it charged, striking like a void on legs.

Its sword cleaved the cave open.

It didn’t cut stone. It removed it.

A long, crescent scar in the floor just vanished beneath the weight of a single swing. Not even dust remained. Just absence.

Mura shifted his feet and reappeared mid-air again. His form coiled into a guard stance as his voice cut through the roar of displaced energy:

"Enma no Tate."

Jin saw it.

The sword didn’t strike out, it pulled in.

The air bent around it, folding into a defensive spiral of curved slashes. Echoes of previous battles reflected in each mirrored cut. It wasn’t spiritual. It wasn’t supernatural. It was perfect practice, a memory of every guard Mura had ever made, layered into one technique.

The demon’s strike collided.

BOOM.

Steel met discipline. And the cave broke.

Not the ceiling or the walls. The world broke stone cracked down the middle, light itself stuttered. The force of their clash shook Jin in the center of his chest like someone had rung a bell through his bones.

And then—

Light.

Blinding. Total. White.

Jin fell backward into it, weightless.

He gasped.

Wood beneath his back. Air, real, breathable air.

The smell of old paper.

His eyes opened.

The library.

He was back.

He blinked hard, heart still thundering, hands slightly shaking as he sat up. The dream didn’t feel like a dream. Not even close. It was memory. Or a message.

Something passed on.

And then he saw the book. The same book on Heian swordsmen, still open beside him.

Only now, a new line etched onto the old parchment at the bottom of the page, as if ink had written itself while he slept:

"Swords never forget."

He stared at the ink for a long time, unmoving. The weight of the dream still pressed against his chest, like phantom steel. A chill passed through him, not from fear, but from knowing.

Swords never forget.

And now, it seemed, his had finally started to remember.