The blizzard did not care that I was on a divine mission to cheat death.
It only cared about burying everything foolish enough to stand upright on the mountain pass.
I leaned heavily against the massive wooden doors of a dilapidated Shinto shrine, shoving them shut against the howling wind with my good shoulder.
The rusted iron hinges screamed in protest, but the heavy oak finally clicked into place, instantly cutting off the deafening roar of the storm outside.
The sudden silence in the cavernous, abandoned hall was jarring, broken only by the ragged, desperate sound of my own breathing.
I collapsed onto the dusty floorboards, my back sliding down the wood until I hit the ground.
My body was tearing itself apart from the inside out.
The Devourer’s Physique was a miracle of biological engineering, but the crash that followed its deactivation was a unique brand of hell.
When I had eaten the flesh of Kairo, the spatial demon, my Iron Stomach had forcibly rewired my visual cortex and synchronized my brainwaves with a demonic frequency.
Now that the flesh was fully metabolized and purged from my system, my baseline biology was desperately trying to reassert itself.
My eyes felt like they were packed with crushed glass.
A cluster headache hammered against the inside of my skull with the rhythmic, agonizing force of a blacksmith’s anvil, and every muscle in my wiry frame trembled with severe caloric depletion.
My hands were shaking so badly I could barely unlatch the leather bandolier across my chest.
I let the heavy belt of Nichirin shotgun shells hit the floor with a metallic clatter, followed by the Sun-Spitter itself.
I unbuckled the moss-green katana from my hip, laying it carefully beside the gun.
“Fire,” I rasped, my voice sounding like grinding stones.
“I need fire.” I forced my trembling hands to gather a small pile of dry, rotted wood from the shattered remnants of an offering box in the center of the shrine.
I didn’t have matches, and rubbing sticks together with severely depleted stamina was a fool’s errand.
I cracked open one of my spare shotgun shells, pouring a small mound of the sunlight-infused iron sand and raw gunpowder onto the wood.
Drawing my katana a fraction of an inch from its scabbard, I struck the steel guard hard against the flint-like edge of the gun barrel.
A spark caught the powder.
It flared brilliantly, instantly igniting the dry rot.
I huddled close to the meager flames, wrapping my tattered purple Demon Slayer uniform tightly around my shoulders.
I reached into my coat and pulled out a ration bar—a dense block of compressed rice, salt, and dried meat.
I took a massive bite, chewing mechanically.
It tasted like ash and disappointment.
After experiencing the nuclear-reactor surge of consuming Upper Moon flesh, ordinary human food felt utterly devoid of substance.
But I ate it anyway, forcing my Iron Stomach to process the mundane calories just to stop my internal organs from cannibalizing themselves.
The fire crackled, casting long, dancing shadows against the statues of forgotten kami lining the walls.
I swallowed the last of the rations and stared into the flames.
“System,” I ordered, my voice low and echoing in the empty shrine.
“Wake up.” The air in front of the fire shimmered.
A sleek, translucent blue holographic screen materialized, hovering perfectly at my eye level, completely unbothered by the ambient heat.
[The Simulation System is online.
Congratulations on surviving another unscripted encounter, Host.] “Skip the fake pleasantries,” I growled, crossing my arms over my chest to trap the body heat.
“At the waystation, you gave me a notification.
Fifteen units of Existential Energy for killing that spatial freak.
That brought my total to one-hundred and eighty-five.
The wager to resurrect Kuina requires one-hundred thousand.” [Correct.
The Resurrection Protocol demands a monumental sum of Existential Energy to reverse a fixed point in the multiverse’s timeline.] “Explain the math,” I demanded, narrowing my eyes at the floating blue text.
“I fought a giant meat-train.
I shot the Upper Moon Three in the arm.
I’ve killed dozens of fodder demons on the mountain, the Hand Demon at Final Selection, and Gokaku in Shirakawa.
Why is my balance barely scraping two hundred?” The blue screen flickered, the text scrolling rapidly as the System switched from its standard notification tone to a deeply mechanical, expository mode.
[Query acknowledged.
Processing explanation of Existential Energy (EE) Yield Mechanics…] [Existential Energy is not a fabricated currency.
It is the metaphysical weight of a soul’s impact on reality.
It is the localized gravity that a being exerts upon the timeline.
A standard, mundane human soul holds negligible weight—roughly 0.001 units.
They live, they die, and the universe does not notice.] [Demons, however, are biological anomalies steeped in the blood of Kibutsuji Muzan.
By defying the natural law of death, they accumulate Existential Energy like a dam accumulating water.
The older and more powerful the demon, the heavier their soul becomes.
When a demon is slain, that accumulated energy bursts outward, attempting to return to the Will of the World to be recycled.] “And you steal it before the world can absorb it,” I deduced, understanding the parasite nature of the System I was bound to.
[Precisely.
I act as a siphon.
However, the Host must be the primary catalyst for the entity’s destruction to claim the yield.
The parameters for harvesting EE are strict.] The screen shifted, displaying a clean, hierarchical list of data.
[Base Fodder Demons: 1 to 5 EE Units.] [Mid-Tier Demons (No Blood Demon Art): 5 to 10 EE Units.] [High-Tier Demons (Weak Blood Demon Art): 10 to 30 EE Units (e.g., Kairo yielded 15, Gokaku yielded 20).] [Lower Moon Kizuki: 100 to 500 EE Units.] [Upper Moon Kizuki: 5,000 to 15,000 EE Units.] [Progenitor (Kibutsuji Muzan): 50,000+ EE Units.] I stared at the numbers, doing the brutal arithmetic in my head.
If I spent the next ten years hunting nameless, weak demons in the woods, I wouldn’t even make a dent in the hundred-thousand requirement.
The vast majority of this world’s Existential Energy was hoarded at the very top of the food chain.
“The Upper Moons and Muzan,” I muttered, a dark, feral smirk tugging at the corner of my mouth.
“That’s where the money is.” [Correct.
To fulfill the Resurrection Protocol, you must hunt the apex predators of this reality.] “Then why didn’t I get a payout for the Mugen Train?” I challenged, leaning closer to the screen.
“I was there.
I fought the tentacles.
I shot Akaza.” [Because you did not secure the kill, Host.
The Lower Moon One (Enmu) was executed by Tanjiro Kamado.
The Will of the World naturally absorbed the released energy because you were acting as a secondary support element within the scripted narrative.
Furthermore, the Upper Moon Three (Akaza) did not die.
You harvested a physical piece of his flesh, granting you temporary biological access to his power via the Devourer’s Physique, but his soul remained intact.
No death equates to no Existential Energy release.] “So I don’t get paid for assists,” I grunted, leaning back against the cold wooden pillar.
“And I don’t get paid for wounding them.
I have to deliver the killing blow.” [You must deliver the killing blow, or severely fracture the Will of the World’s script by executing a major antagonist outside of their designated narrative checkpoint.
However, be warned: The WoW actively protects the Kizuki.
If you attempt to hunt them prematurely, the universe will deploy immune responses to erase you.] “I know,” I said, remembering the suffocating, crushing gravity in the Butterfly Mansion’s courtyard when I had merely insulted Sanemi.
“The universe wants its precious protagonist to do all the heavy lifting.
It wants the tragedy and the drama.” I closed my eyes, listening to the wind howl against the reinforced doors of the shrine.
The rules of the game were finally crystal clear.
I was trapped in a fragile body, forced to play the role of a secondary character in a predetermined play.
If I tried to break the script too early, the universe would crush me.
But if I just followed the script perfectly, letting Tanjiro Kamado get all the kills, I would never harvest the hundred-thousand units of energy I needed.
I had to walk a razor’s edge.
I had to let the Will of the World set the stage, let the protagonist initiate the major battles, and then, at the absolute climax, I had to step in and steal the execution.
I had to become the ultimate opportunist.
I reached out and placed my hand on the hilt of the moss-green katana.
In my past life, in the East Blue, such a tactic would have disgusted me.
Roronoa Zoro fought his opponents head-on, with honor, demanding nothing less than an absolute clash of wills.
Sneaking around and stealing kills was the realm of cowards and pirates.
But I wasn’t just a swordsman anymore.
I was a man who had made a deal with the devil to bring a girl back from the dead.
In the dark of the shrine, Kuina’s face flashed in my memory.
I saw her confident smirk, the way she held her wooden practice sword, and the absolute injustice of the slate roof tile that had ended her life simply because the universe dictated it.
The universe didn’t care about honor.
It only cared about its rules.
I would play dirty.
I would use guns, I would eat demon flesh, and I would steal every single soul this world had to offer if it meant I could rewrite her fate.
“System,” I said, opening my eyes, the golden, predatory light briefly flashing in my irises.
“Close.” The blue screen shattered into digital dust and vanished.
I spent the rest of the night in a state of shallow, hyper-aware meditation.
I focused on my breathing.
Not the magical, elemental breathing of the Hashira, but the fundamental, biological control of my own heart rate and muscle tension.
Genya Shinazugawa’s body was a weak vessel, but it was mine now.
If I couldn’t rely on the Devourer’s Physique for permanent strength, I had to push this baseline biology to its absolute breaking point.
I forced my muscles to tense and relax in microscopic increments, actively combating the cellular fatigue of the crash.
When dawn finally broke, the howling of the blizzard faded into a hollow, whistling breeze.
I pushed the heavy wooden doors of the shrine open.
The morning sun reflected blindingly off the fresh, untouched powder that blanketed the mountain pass.
The air was crisp, painfully cold, but completely devoid of any demonic taint.
I stepped out onto the porch, buckling the moss-green katana to my left hip and sliding the Sun-Spitter into the holster on my right.
“Caw!
Caw!
Lazy human!
The sun is up!” My Kasugai crow descended from the clear blue sky, landing on the torii gate at the entrance of the shrine.
It looked entirely unbothered by the freezing temperatures.
“I killed your spatial demon, bird,” I called out, my breath pluming in the cold air.
“Tell the Corps the pass is clear.” “Old news!
Caw!
The pass is clear, but the city is dark!” the crow shrieked, flapping its wings aggressively.
“New orders!
New orders!
Head Southeast!
To Tokyo!
The red-light district of Yoshiwara!” I paused, resting my hand on the polished oak stock of my shotgun.
“Yoshiwara,” I repeated, the name clicking into place with the vague, fragmented timeline the System had downloaded into my brain upon transmigration.
“Yes!
Caw!
The Sound Hashira, Tengen Uzui, is mobilizing!
Rumors of missing women!
Courtesans vanishing in the night!
The Corps suspects demonic activity!
You are ordered to rendezvous and assist in the infiltration!
Go!
Go!” The crow took off, circling once before darting toward the southeast horizon.
I stood on the snowy steps of the shrine, a slow, dangerous smile spreading across my face.
Yoshiwara.
The Entertainment District.
I knew exactly what was hiding among the neon lights, the perfume, and the painted smiles of the courtesans.
It wasn’t a swamp demon, and it wasn’t a spatial trickster.
It was the Upper Moon Six.
Two demons sharing a single title.
A massive stockpile of Existential Energy just waiting to be harvested.
The Will of the World was officially moving the script to its next major act.
Tanjiro, Zenitsu, and Inosuke would already be on their way, dragged into the chaos by the eccentric Sound Hashira.
The universe expected me to show up, play my role as the angry, gun-toting outcast, and serve as background support while the protagonist unlocked his hidden potential.
“Alright,” I whispered to the empty mountain pass, my golden eyes locked on the southeastern horizon.
“I’ll play your game, universe.
I’ll hit your marks.
I’ll let the Hashira take the vanguard.” I unlatched the Sun-Spitter, cracking the double barrels open with a crisp, heavy shuck.
The brass shells gleamed in the morning light.
I snapped the gun shut with a vicious clack and slid it back into the holster.
“But when the Upper Moon’s neck is on the line,” I promised the cold wind, stepping off the porch and beginning the long trek down the mountain, “I’m pulling the trigger.”