The Core Room door sealed shut behind them with a deep metallic thud—the kind of sound that didn’t just close a room, but buried something. A finality.

  Z-69 stepped out first, boots scraping lightly against the steel floor of Level 10’s corridor.

  The air here was always cold—manufactured cold, calculated cold—like the entire floor was a lung that breathed recycled frost.

  Lumina lay curled on his shoulder, fur barely glowing, tiny breaths trembling with exhaustion.

  Draining her psychic energy completely always left her sluggish and glassy-eyed, like a lantern whose flame had been stretched too thin.

  Z-69 turned his head slightly to the left.

  Where Ten should have followed.

  But there was nothing.

  No uncertain footsteps trying to keep up with him.

  No shaky breathing.

  No timid “hey… wait…”

  Only silence.

  Not even an aftertaste of presence.

  Lumina blinked slowly, her tail sliding off her back like a wilted leaf.

  “Where’s the kid…?”

  “Gone.” Z-69 said, voice steady and flat, as though he were describing the weather.

  “His task is done.”

  He didn’t sigh.

  He didn’t frown.

  He simply acknowledged the empty space where Ten used to stand.

  Lumina’s ears drooped.

  “That’s… kinda sad.”

  But sadness didn’t echo here.

  Level 10 swallowed emotions the way rust swallowed old metal.

  Z-69 stepped forward, and Lumina clung a little tighter, her small body seeking warmth from something that wasn’t warm.

  The noise hit them the moment they cleared the hallway.

  Level 10’s plaza roared like a beast straining against its chains.

  Gamblers shouted over one another, their voices mixing with the static buzz of neon advertisements.

  Robot enforcers stomped overhead on patrol rails, their movements synchronized like a metallic heartbeat.

  The smell was a collage of violence:

  burned grease, stale smoke, the metallic sweetness of dried blood half-scrubbed from the tiles.

  Z-69 walked through it like a ghost.

  Unaffected.

  Untouched.

  A massive hologram screen flared to life above his head, showering the plaza in harsh blue light.

  A robotic voice announced:

  “Contestant Number 69 — Round Two complete.”

  “Status: QUALIFIED for Round Three.”

  “Data: UNMEASURABLE.”

  The crowd erupted instantly.

  “That’s number 69!”

  “That white-haired freak — he took down a heavy-class drone!!”

  “No records at all. What a monster!”

  “Bet on him now!!!”

  “No ranking? No data? What the hell IS he?!”

  A rain of digital confetti burst across the ceiling.

  Unauthorized content usage: if you discover this narrative on Amazon, report the violation.

  Lumina, finally awake enough to be snarky, snorted.

  “Elise really gave you a lucky number, huh?”

  Z-69 looked at the screen with an unreadable calm.

  “Coincidence.”

  “…You sure? I don’t think so.” Lumina narrowed her eyes.

  Z-69 offered no further comment.

  The hologram flickered again, listing the twenty contestants who survived into Round Three.

  Mugshots.

  Power signatures.

  Kill counts.

  Professionals.

  Monsters.

  People carved and rebuilt by violence.

  And then:

  “Contestant Number 69 — EMPTY DATA. UNCLASSIFIED.”

  A ripple of confusion passed through the plaza like electricity skittering across metal.

  Z-69 turned his back.

  He had no interest in speculation.

  A metallic chime struck through the air—clear, sharp, almost ceremonial.

  “Official Announcement for Round Three — commencing.”

  The main doors of the arena rumbled, then peeled open like the jaws of an iron beast.

  Within lay a vast colosseum—stone ribs and neon veins, ancient brutality fused with electric modernity.

  The announcer robot hovered high above, lights tracing its skeletal frame.

  “ROUND THREE — THE ARENA.”

  “One-on-one duels.”

  “Random terrain selection.”

  Panels unfolded behind it, projecting environments:

  “VARIABLE GRAVITY.”

  “RUINED CITY.”

  “THERMAL DESERT.”

  “DILUTED ACID CHAMBER.”

  “LOW-OXYGEN ZONE.”

  A cheer mixed with fear spread across the spectators.

  Lumina frowned.

  “I don’t like the word random. Nothing here is random.”

  Z-69 touched the Heaven-Sundering Short Blade.

  The metal vibrated faintly under his fingers, like it recognized the battlefield ahead.

  A voice—smooth as a razor dipped in honey—cut into the air.

  “That’s because Round Three is… special.”

  Elise emerged from behind a flickering hologram panel, her black coat and pink hair catching the neon like fire running down silk.

  Her covered left eye added a strange asymmetry—softness on one side, danger on the other.

  She looked at Z-69 the way a scientist looked at a rare specimen: with admiration, calculation, and quiet hunger.

  “Congratulations, Mr. Contestant Number 69”

  Lumina immediately bristled.

  “Grrr…”

  Elise smiled—gentle on the surface, lethal beneath.

  “No need to get jealous.”

  “I AM NOT JEALOUS!” Lumina barked telepathically, and then buried her face deeper into Z-69’s neck like a child caught lying.

  Z-69’s gaze remained steady.

  “Why are you here?”

  “To warn you.” Elise said lightly.

  “Round Three is monitored by Level 9. And you… interest them greatly.”

  Her smile sharpened.

  “So do me a favor. Don’t show your full power. If they understand what you really are, they’ll try to capture you.”

  “I’ll consider it.”

  “I know you will.”

  Elise stepped back, her perfume slipping into the cold air like a metallic wisp.

  “Don’t disappoint me.”

  She vanished into the crowd— not walking away, but disappearing the way a blade leaves its sheath.

  Lumina puffed her cheeks.

  “I hate her.”

  “I noticed.” Z-69 said, giving her small head a soft pat.

  John’s safehouse crouched in the middle of the slums like a tired animal—shaking with generator noise, leaking light from its seams, and smelling strongly of burned circuits and cheap caffeine.

  When Z-69 opened the door, John didn’t look up.

  He was soldering something that didn’t look legal or stable.

  “Oh. You’re alive.”

  He slurped from a mug that hissed faintly.

  “Good. I just finished brewing energy coffee.”

  Z-69 placed the Heaven-Sundering Short Blade on the table with a soft metallic ring.

  “I need more information.”

  John blinked.

  “You’re pretty studious lately. Every time I blink, you’re here asking for more intel.”

  “I need to know more about the world, about my opponents and about myself.”

  John snuffed out his cigarette.

  “Fine. Let’s start from the top.”

  He spun a small projector, and a holographic pillar of data rose between them.

  “Combat ranks. From F to S. And Z-class…That’s not a rank. That’s a warning label.”

  Z-69 asked plainly:

  “What rank am I?”

  John pointed a screwdriver at him.

  “Your biological body? Rank D. Like a slightly stronger human.”

  Lumina yelped.

  “Rank D?! That’s baby-level!”

  John lifted a finger.

  “But with your regeneration, reflexes, and purple lightning, your actual combat ability is around Rank B.”

  Z-69 absorbed this without changing expression.

  “Only that?”

  John nearly fell out of his chair.

  “‘ONLY’? You destroyed a Heavy-Class War Drone with your bare hands!”

  He tapped the hologram again.

  “Rank S is for the freaks who used to protect the surface. People like—well—you, the one and only Immortal Thunderlight, before you died.”

  Z-69 tilted his head.

  “And Z-class?”

  “That’s not a ranking. That’s a classification for monsters beyond the scale.”

  He pointed at again Z-69.

  “Aside from being a S Rank, You were also the 69th Z-class subject. Hence: Z-69.”

  Lumina’s eyes widened.

  “So he used to be insanely strong?!”

  Z-69 shrugged.

  “I don’t remember.”

  John groaned.

  “I swear your memory is like rotten tofu. Soft. Broken. Smells weird.”

  He switched screens again.

  “Anyway. Your Round Three opponents.”

  Profiles appeared one by one.

  “Krow. Gravity manipulator. Rank B+. He can crush bones without touching you.”

  “Mira. The North Gate Monster. Rank B. Skin like steel. Muscles like industrial pistons.”

  “Ashen. Cybernetic assassin. Rank B-. Predicts your movement through mechanical vision.”

  “Galeon. Air-type. Rank C+. Suffocates enemies by manipulating pressure.”

  “Jin. Speed-type. Rank B. If he hits your core once, that’s it.”

  John leaned back.

  “You can beat them all. As long as you don’t enter Hunger Mode.”

  Z-69 nodded.

  “Good.”

  John threw his hands up.

  “That’s supposed to worry you!”

  “I’m not used to worrying.”

  “I’ll worry for him.” Lumina yawned.

  Night in Level 10 was never truly night.

  The neon lights glowed like a corrupted aurora, painting the district in shades of blood and ultraviolet poison.

  From the safehouse window, the arena looked alive—breathing, rumbling, calling.

  Z-69 stood silently, watching the lights flicker across the ruined skyline.

  He held the Heaven-Sundering Short Blade loosely, its violet light pulsing in rhythm with the crystal embedded in his chest.

  A heartbeat that wasn’t entirely his.

  Lumina rested her head on his shoulder.

  “You’ll win… right?”

  “I don’t know.” Z-69 answered honestly.

  “But I will fight.”

  Lumina smiled softly.

  “That’s enough.”

  Z-69’s fingers brushed the crystal in his chest.

  It trembled—soft, frantic—like something inside remembered a truth he had forgotten.

  Outside, the speakers blared:

  “24 hours remaining — THE ARENA — begin preparations.”

  Cold air blew across his face.

  Z-69 opened his eyes, violet light reflecting in their depths.

  “I will win.”

  And Level 10, for a moment, went quiet.