The journey to Mount Shumisen was not swift, nor was it safe. The mountain range rose like jagged teeth against the horizon, peaks shrouded in mist, valleys crawling with predators both human and natural. Few dared to cross its treacherous slopes. To most shinobi, it was a forgotten graveyard of failed missions and unspoken legends.
But to Kirito, it was a beacon.
He traversed its ridges under the cover of night, his chakra suppressed, his movements ghostlike. For two weeks he searched, combing through caves, ruins, and abandoned outposts. Each day blurred into the next—rain-soaked cliffs, cold winds biting at his cloak, the metallic taste of anticipation on his tongue.
At night, he studied faint traces: footprints half-buried in mud, chakra residue clinging to stones, whispers of movement carried by the wind. Hiruko had hidden himself well, but not perfectly.
By the fifteenth day, Kirito stood before a cliffside waterfall. To an ordinary eye, it was nothing but water crashing down into a basin. But to his gaze—keen, sharpened by Hyūga research and his own ingenuity—the flow distorted unnaturally. A genjutsu veil.
He smirked.
"Finally."
Slipping into the cascade, he passed through the illusory water and emerged in a cavern lit by torches. Ahead stretched a carved tunnel lined with crude but functional traps. Kunai launchers, paper bombs, chakra-triggered seals. All designed to deter intruders.
For anyone else, it would have been a death sentence. For Kirito, it was nothing more than an exercise. His chakra threads slithered into the mechanisms, severing them silently. Each step forward was calculated, each movement precise.
The tunnel opened into a vast underground complex—Hiruko's lair.
The first guard barely had time to register the shadow that passed him. A thin thread of chakra slit his throat before he could cry out. He collapsed without a sound, blood pooling at his feet.
The second fell moments later, dragged into darkness by invisible strings, his neck snapping with a faint crack.
Kirito moved like a phantom. His shadow clone dispersed traps in parallel while his real body advanced deeper. Guards patrolled in twos and threes, their armor marked with Hiruko's insignia, but none lived to raise an alarm. Their bodies were dragged into alcoves, lifeless eyes staring at stone.
Inside one chamber, he found a group of shinobi dissecting an unconscious prisoner. Their scalpels gleamed under torchlight, their laughter low and cruel. They didn't notice when the flames dimmed. They didn't hear the whisper of threads sliding across their skin.
When the light returned, their bodies were already slumped over their own tables, throats pierced cleanly. Kirito stepped over them without pause, collecting the scrolls and vials they had been cataloging.
Room by room, the base became a mausoleum. Laboratories were stripped bare, documents and samples sealed into Kirito's storage scrolls. Notes on elemental fusions, diagrams of human anatomy, forbidden seals half-finished—all were claimed.
The deeper he went, the more grotesque the sights became. Chambers lined with failed experiments—misshapen clones twitching weakly, bodies fused unnaturally, eyes staring in blind agony. Kirito paused only briefly to observe, his expression unreadable.
"They lacked vision. They lacked control. Waste."
A swift strike ended their suffering, and silence reclaimed the halls
In a large archive chamber, Kirito struck gold. Scrolls bound in seals lined shelves from floor to ceiling. Some glowed faintly with protective wards, others nearly crumbled with age. He broke the seals with methodical precision, unrolling one after another.
"Chimera Technique… fusion of kekkei genkai through absorption. Crude, but effective. Notes on elemental blending… fire with wind, lightning with water… flawed but promising. Dark Release—absorption and redirection of chakra, versatile in both offense and defense…"
His hands moved swiftly, sealing scrolls into storage one by one. Every scrap of Hiruko's research, every piece of forbidden knowledge—he would take it all.
But even as he worked, he knew this was only the surface. The heart of Hiruko's work lay deeper.
And finally, he found it.
A heavy door barred his path, reinforced with chakra seals. The hum of energy radiating from it was palpable, like standing before a caged storm. Behind this door, the true laboratory awaited—the place where Hiruko himself worked.
Kirito placed his palm against the seal, chakra threads probing its structure. Complex, multi-layered, designed to resist intrusion. He smiled faintly.
"Impressive. But not enough."
With a twist of chakra, the seal collapsed. The door shuddered and opened with a grinding noise, revealing a chamber bathed in eerie green light
Rows of tubes lined the walls, each filled with liquid that preserved twisted experiments—human forms fused with unnatural traits, eyes glowing faintly, limbs reshaped by grotesque chakra mutations. The air was thick with chemical fumes and the stench of burning chakra.
At the center stood a figure hunched over a restrained subject, hands weaving seals with unnatural speed. His cloak was tattered, his hair dark and unkempt, his aura suffused with malevolent intent.
Hiruko.
Once a shinobi of Konoha, now a twisted seeker of forbidden power. His experiments had turned him into a monster feared and hunted by the world. And yet, to Kirito, he was not a monster—he was a prize.
Kirito stepped silently into the chamber, his presence cloaked. The guards at the edges of the room slumped to the ground one by one, throats slit by invisible strings before they even noticed him.
Only Hiruko remained, too absorbed in his work to sense the predator now watching him.
Kirito's gaze flickered to the scrolls on Hiruko's table, the notes scattered across the floor, the chakra seals engraved into the very walls. All of it would soon be his.
The time for stealth was over.