I stood there on the rooftop, the night air thick with the metallic tang of blood and the acrid smoke of gunfire echoing from the camp below. The transformation into this... Gun Fiend form, Aki Hayakawa, The Gun Devil template—had left me feeling like a stranger in my own skin. No, not skin. Metal. Cold, unfeeling alloy fused with whatever was left of my humanity. The barrel protruding from my forehead felt like a third eye, always watching, always ready to spit death. My left arm, now this grotesque M4 carbine extension, hummed faintly, as if eager for the violence to come. Kokushibo's power had been intimate, up-close—a dance of blades under the moon's indifferent gaze. This? This was detachment. Distance. A devil's precision engineered for mass extermination.
I flexed the rifle arm experimentally, hearing the faint click of chambers aligning. Five percent synchronization. The system's words still burned in my mind like a glitchy hologram. Only five percent of the Gun Devil's full potential, and already I felt like I could level a city block without breaking a sweat. But the cap on it—the need to grind through mutated zombie blood to inch closer to full power—felt like a cosmic joke. In Chainsaw Man, twenty percent of this devil's power had wiped out over a million lives worldwide in seconds. Buildings crumpled, skies rained bullets, entire populations erased in a hail of lead. What would a hundred percent do here, in this fractured world? Probably end it all. Wipe out every last shambling corpse, every desperate survivor, every flickering spark of life until nothing remained but silence and ruins. The thought sent a chill through my circuits—or whatever passed for nerves now. Overpowered didn't even begin to cover it. And here I was, starting at the bottom rung, farming zombies like some low-level grind in a forgotten game.
"Why the limit?" I'd asked the system earlier, my voice a metallic rasp that echoed unnaturally in the night.
[HOST QUERY: SYNCHRONIZATION CAP EXPLAINED. FULL ACCESS TO GUN DEVIL TEMPLATE REQUIRES PROGRESSIVE INTEGRATION TO AVOID SYSTEM OVERLOAD. ABSORB MUTATED SPECIMEN BLOOD TO INCREASE PERCENTAGE. STANDARD ZOMBIES YIELD MINIMAL GAINS; HIGHER-TIER MUTANTS PROVIDE SUBSTANTIAL UPGRADES.]
"And Kokushibo? That was full sync from the start."
[BEGINNER PACKAGE: INITIAL TEMPLATE PROVIDED AT 100% FOR HOST FAMILIARIZATION. SUBSEQUENT TEMPLATES DEMAND EARNED PROGRESSION FOR BALANCE.]
Balance. Right. Because turning into a demon swordsman overnight was "balanced," but embodying a devil that could end civilizations needed baby steps. Fine. If the path to godhood was paved with zombie guts, I'd walk it. The camp below was a buffet—thousands of undead swarming the crumbling defenses, mutants leading the charge like twisted generals. Time to test this out.
I leaped from the roof, the drop a controlled plummet. Wind whipped at my suit, the tie flapping like a noose in the gale. I landed amid a cluster of shamblers, the impact cracking asphalt and sending two of them sprawling. No elegance here—no Moon Breathing forms to channel. Just raw firepower. I raised the rifle arm, the barrel spinning up with a mechanical whine that cut through the moans.
The first burst tore into a pack of normal zombies shambling toward a barricade of overturned vehicles. Bullets—infused with that devilish essence—ripped through rotten flesh, heads exploding in sprays of dark ichor. They dropped like puppets with cut strings, bodies convulsing briefly before going still.
[STANDARD ZOMBIE ELIMINATED x5]
[GUN DEVIL SYNCHRONIZATION: +0.01%]
[TOTAL: 5.01%]
Barely a blip. Like the system said—minimal gains from the fodder. I pivoted, spotting a mutated one: a hulking brute with elongated arms ending in bone scythes, charging a group of survivors huddled behind sandbags. It swung, cleaving through a soldier's rifle like butter.
I aimed. Fired.
The volley stitched across its chest, each impact blooming with explosive force. It staggered, roaring, but I didn't let up—another burst to the head, pulverizing the skull into fragments.
[MUTATED ZOMBIE ELIMINATED]
[GUN DEVIL SYNCHRONIZATION: +0.03%]
[TOTAL: 5.04%]
Better, but still a drop in the ocean. The survivors behind the sandbags glanced my way—a mix of soldiers and civilians, their faces smeared with dirt and blood. One soldier, a grizzled vet with a bandaged arm, locked eyes with me. Or tried to—my featureless face probably didn't give much to lock onto. He nodded once, a curt acknowledgment, before turning back to the fray. No thanks, no questions. They had their own asses to save; some suit-wearing freak with a gun for an arm was just another variable in the apocalypse. Fine by me. I wasn't here for heroics.
I pressed forward, the system's pings becoming a rhythmic drumbeat in my skull. Each kill added a fraction, a tease of the power lurking just out of reach.
A swarm of lesser zombies poured from a breached fence—dozens, their moans a collective dirge. I swept the rifle arm in an arc, unleashing a sustained burst. Bodies jerked and fell, limbs severed, torsos ventilated. It was like mowing grass, if grass screamed and bled.
[STANDARD ZOMBIE ELIMINATED x12]
[GUN DEVIL SYNCHRONIZATION: +0.02%]
[TOTAL: 5.06%]
Not enough. I needed the big ones. Spotting a cluster of mutants tearing into a command tent—acid-spitters melting canvas and flesh alike—I charged. The forehead barrel fired first, a precise shot that cored one spitter's gland, causing it to erupt in a backfire of corrosive goo that melted its own face.
[MUTATED ZOMBIE ELIMINATED]
[GUN DEVIL SYNCHRONIZATION: +0.10%]
[TOTAL: 5.16%]
The others turned, hissing. I unloaded, bullets tracing glowing arcs in the dark. One with tentacle whips lashed out, but I sidestepped, the rifle arm barking in response. Tentacles shredded, body following suit.
[MUTATED ZOMBIE ELIMINATED]
[GUN DEVIL SYNCHRONIZATION: +0.08%]
[TOTAL: 5.24%]
A bone-armored tank barreled through, shrugging off initial hits. I adjusted—aimed for joints, weak points glowing in my enhanced vision like target overlays. Rounds punched through, cracking armor, until it collapsed in a heap.
[MUTATED ZOMBIE ELIMINATED]
[GUN DEVIL SYNCHRONIZATION: +0.20%]
[TOTAL: 5.44%]
The pings kept coming, each one a tiny victory in a sea of fractions. Twenty percent in Chainsaw Man had global kill counts in the millions—tsunamis of bullets from nowhere, erasing lives en masse. Here, at five percent, I was already turning the tide in this pocket of hell. But full sync? A hundred percent would be apocalyptic. Wiping out every zombie, every human, every scrap of life in this world without breaking a sweat. The power scale was insane; no wonder the system gated it behind this grind. One percent felt like eternity at this rate—killing hundreds, thousands, and barely nudging the needle.
I moved deeper into the camp, the rifle arm never cooling. A family dashed across my path, pursued by a pack. I cleared them with a burst, bodies dropping mid-stride.
[STANDARD ZOMBIE ELIMINATED x7]
[GUN DEVIL SYNCHRONIZATION: +0.01%]
[TOTAL: 5.45%]
The father glanced back, mouthing a silent "thanks" before vanishing into the shadows. Others noticed too—a soldier reloading his pistol paused, watching me ventilate a mutant that had flanked his position. He didn't approach, didn't speak. Just nodded and kept fighting. Survival first; questions later. Or never.
Hours blurred into a relentless cycle: spot, aim, fire, absorb. The system's voice became white noise.
[MUTATED ZOMBIE ELIMINATED]
[GUN DEVIL SYNCHRONIZATION: +0.05%]
[TOTAL: 5.50%]
[STANDARD ZOMBIE ELIMINATED x9]
[GUN DEVIL SYNCHRONIZATION: +0.01%]
[TOTAL: 5.51%]
[MUTATED ZOMBIE ELIMINATED]
[GUN DEVIL SYNCHRONIZATION: +0.15%]
[TOTAL: 5.66%]
My mind wandered amid the slaughter. Was this what power felt like? Detached annihilation? Kokushibo's kills had been personal, each slice a meditation. This was industrial—efficient, emotionless. I wondered about Ariya; her presence flickered on the edge of my senses, carving her own bloody path. She'd grown, no doubt feeding on the "bad" ones. Good for her.
But then, something cut through the monotony. A mutant unlike the others. It shambled from the shadows of a ruined barracks, its head overgrown with fungal tendrils, plates of hardened mycelium covering its face like a grotesque mask. No eyes visible, just clicking mandibles and spore-dusted skin. It moved with eerie purpose, head tilting as if listening for prey.
I froze mid-step. "A Clicker? From The Last of Us?"
I'd binged that show in my old life—post-apocalyptic fungus zombies turning people into blind, echolocating horrors. But this world was supposed to be straight zombie apocalypse, virus-based, with mutations from eating humans. Not cordyceps brain infections. Had I been wrong all along? Months of slashing shamblers, and now this? Was this a mixed world, some crossover hell?
The system chimed, unbidden.
[NEW ZOMBIE VARIANT DETECTED: CLICKER]
[ORIGIN: CORDYCEPS BRAIN INFECTION (THE LAST OF US)]
[VIRUS EXPLANATION: FUNGAL PARASITE OPHIOCORDYCEPS UNILATERALIS ADAPTED TO HUMAN HOSTS. SPORES INFECT VIA INHALATION OR WOUNDS, REPLACING BRAIN TISSUE WITH MYCELIUM NETWORK. HOST LOSES SIGHT BUT GAINS ECHOLOCATION VIA CLICKING VOCALIZATIONS. ADVANCED STAGES FORM ARMOR-LIKE PLATES. HIGHLY AGGRESSIVE, DRAWN TO SOUND. UNRELATED TO PRIMARY NECROTIC VIRUS; POTENTIAL HYBRID ECOSYSTEM DETECTED.]
Hybrid ecosystem? My hair stood on emd. So this wasn't just one virus. There were layers. Cordyceps here, but what else? Rage virus from 28 Days Later, turning people into sprinting berserkers? Blacklight from Prototype, reshaping bodies into weapons? Green Flu from Left 4 Dead, with its special infected? Wildfire from The Walking Dead, the slow-burn reanimation? The thought made my mechanical parts whir uneasily. If viruses were mixing, evolving together, this world was more screwed than I'd imagined.
But me? I had cheats. Templates, systems, devil powers. I shrugged it off—or tried to. Worry gnawed at the edges: what about the people? The survivors scrambling below, fighting for scraps of life. How would they last against layered horrors? Clickers that hunt by sound, mutants that spit acid, whatever else lurked. Should I help them? Play hero? Or stick to the grind, build power, let the weak fend for themselves?
The Clicker answered for me. It zeroed in on a fleeing mother and her daughter, the woman's arms wrapped protectively around the child as they darted between debris. The Clicker clicked rapidly, fungal head swiveling, then lunged—tendrils whipping forward like living vines.
No time for philosophy. I raised the rifle arm, the barrel locking on. Distance was my ally now.
Burst fire. Three rounds to the head plating—cracks formed, spores puffing out. It staggered but kept coming. I adjusted, pouring more lead. The fourth and fifth punched through, shredding the fungal core. It dropped mid-leap, body crumpling like wet paper.
[MUTATED ZOMBIE ELIMINATED (VARIANT: CLICKER)]
[GUN DEVIL SYNCHRONIZATION: +0.12%]
[TOTAL: 5.78%]
The mother skidded to a halt, clutching her daughter. She turned, eyes searching the dark for her savior. They landed on me—silhouetted against the flickering fires, stepping into a pool of moonlight.
From her perspective: He emerged from the shadows like a nightmare in a suit. Tall, broad-shouldered, dressed in a crisp black business suit that seemed absurdly out of place amid the gore. His hair was wild, black strands falling over a face that... wasn't right. A smooth, pale skin broken by a cold steel gun barrel jutting from his forehead like a twisted horn. From the back of his head, a hammer protruded, metallic and menacing. His left arm... God, his left arm wasn't an arm at all. It was a rifle, fused seamlessly at the shoulder, barrel still smoking from recent fire. He moved with unnatural grace, each step deliberate, like a machine built for one purpose: death.
She was about to stammer a thank you, relief flooding her face. But then the details hit— the barrel, the hammer, the arm. This wasn't a man. This was another monster, perhaps worse than the one he'd just killed.
She froze, body locking up as primal terror gripped her. Her daughter, peeking from behind her legs, saw it too—the faceless thing with guns for limbs. The girl whimpered once, then went silent, trembling against her mother's side.
I stood there, the system's ping fading in my mind. Help them? Or not? The question hung heavier now, but the night wasn't done with its surprises. More clicks echoed from the dark—another pack incoming. The grind continued.