The sky inside the Trial Zone never changed.
It hung overhead like molten glass; red, cracked with flickers of black lightning, casting the forest floor in an eerie glow that made every shadow crawl. Mist swirled low around Kairo's ankles, curling like smoke from a dying fire.
The silence after the last construct shattered was unbearable.
Kairo leaned against a half-charred tree, chest rising and falling in ragged breaths. His knuckles bled. His legs burned.
The system flickered before his eyes.
DING!
~----~
[MUSCLE INDEX: 2.0%]
Skill Unlocked: [Muscle Lock]
>Harden muscle groups to reduce blunt-force trauma.
[Duration: 3 seconds per use]
[Cooldown: 15 seconds]
[Energy Cost: 8% of daily caloric requirement.]
…
[Note: Efficiency suffering due to extreme caloric deficit. Hunger approaching danger zone.]
~----~
His stomach twisted in knots.
He hadn't eaten in over a day.
The energy his muscles demanded was brutal, each charge drained him like a fire eating dry wood. He could feel his reserves collapsing, yet he didn't stop.
Because stopping meant falling behind.
And falling behind meant being forgotten again.
His squad huddled in the clearing, dazed.
The girl, Mira, sat cross-legged, inspecting a deep gash across her arm with practiced ease. Short, blunt hair, tough skin; she was the only one who hadn't panicked earlier when the construct attacked.
The boy in dull armor, Davin, paced, muttering calculations to himself.
"Golem response time is predictable… if you count the core flares, they follow a 2-4-3 burst pattern… but that one… that one wasn't listed in the archives".
Kairo stared.
"What archives?"
Davin blinked, surprised. "You didn't get the Nexus prep manuals?"
Kairo shook his head slowly.
Mira chuckled darkly. "Figures. Slum kid, huh?"
Kairo said nothing.
She shrugged. "Don't get all prickly. I don't care where you're from, just don't get killed".
He nodded once.
Another boy; tall, gangly, and nervous leaned over. "What even is your ability, man? You don't have any mana trials… but you punch like a boulder".
Kairo glanced at his hands. The skin was cracking from the strain, his knuckles were split.
"…Muscle Genesis". He said.
The boy blinked. "Is that even a real ability?"
Mira's lip twitched. "It is now".
...
Sometime later, a flare shot into the sky.
It exploded in a crimson X that hung overhead. The system chimed again, this time deeper. More ominous.
DING!
~----~
[TRIAL ESCALATION TRIGGERED]
Zone Threat Level: Upgraded.
Dungeon-class Construct has been deployed.
Objective remains: SURVIVE.
["Only through fire are blades tempered."]
~----~
Silence.
Then a sound; wrong, deep, wet, slithering through the trees like grinding bone. Kairo caught on to it quickly.
He stood instantly, body tensing. He activated Muscle Lock across his forearms.
His skin hardened; not like armor, but like condensed cable, every fiber contracting to reinforce structure. It felt like being dipped in cold fire.
~----~
[Muscle Lock: Duration – 3 minutes]
Cooldown will begin after effect expires.
Damage Resistance to Physical Blows: Moderate (Location-Specific)
~----~
The others backed toward him instinctively.
They didn't know him.
But they knew strength when they saw it.
It emerged from the mist with a hiss that peeled bark from trees. Seven feet tall, bipedal, and twisted.
It resembled a human-shaped serpent, but half its body was steel; rusted plates fused into muscle, thorns of bone piercing out at every joint.
Its face was an iron helm carved into a cruel grin. Its left arm ended in a serrated jaw, its right in a cleaver the size of Kairo's chest.
Its core pulsed in its gut; exposed, molten, alive.
"WHAT… STAYS… STANDING?" it growled in a voice of metal grinding on stone.
No one answered.
It charged.
Davin screamed and cast a flash barrier as light flared between the trees. Mira rolled aside, drawing dual knives.
Kairo ran straight in.
His brain screamed don't.
But something deeper said, 'If I don't face this, I'll never grow!'
He activated Hypermuscle Creation across both legs and shoulders.
[Hypermuscle Charge: 3/5]
His speed spiked.
He darted under the cleaver, barely, then drove his elbow into the construct's midsection. The impact sent out a shockwave.
BANG!
The construct reeled.
Its molten core flickered.
Kairo spun, dropped low, and swept its leg, but it didn't fall. It pivoted mid-air, slamming the cleaver down.
He barely raised his forearm when…
CLANG!
The blow numbed his arm completely as pain shot through his arm like lightning, but it didn't break.
Muscle lock held.
DING!
~----~
[Incoming Damage Mitigated by Muscle Lock]
Bone Stress: High (Non-fracture threshold)
Effect Duration Remaining: 2 minutes, 21 seconds.
~----~
The construct's claw whipped around, catching him across the ribs.
He flew backward into a tree. It cracked from the impact.
Blood filled his mouth.
Mira lunged while the construct was distracted, her blades slashing through the core's outer casing. Sparks flew.
In response, the construct roared and backhanded her, sending her sprawling. On the other side, Kairo finally forced himself up.
He could barely breathe.
His ribs were cracked, but the system pulsed.
~----~
[MUSCLE INDEX: 2.4%]
Pain Threshold Achieved – Adaptation Bonus +3% Strength for 2 Minutes.
Adrenaline Spike Detected – Emergency Charge Unlocked.
…
[EMERGENCY ABILITY: MUSCLE SURGE]
>Temporarily overrides muscle limits for one explosive action. Use with caution. Cooldown: 1 day.
~----~
Kairo stood.
The construct turned toward Mira.
Kairo exploded forward, putting everything into his legs, channeling everything into his back.
WHOOSH!
He blurred.
His fist slammed into the construct's exposed core with the full weight of his being; no technique, just force.
BOOM!
The core ruptured.
The construct's body went limp, collapsing into a heap of slag and shattered bone as smoke rose.
Kairo dropped to one knee, panting, blood dripping from his nose and ears.
His forearms trembled as Muscle Lock expired. The sensation was like stone turning back into raw flesh.
DING!
~----~
[Muscle Lock Duration Expired]
Cooldown: 15 minutes
~----~
Kairo could feel the ache beneath the surface; the way his fibers had been held too tight for too long. The aftershock of compression was real, but it had saved his life.
The others stared. No one spoke.
The system voice returned.
~----~
[DUNGEON-CLASS CONSTRUCT ELIMINATED!]
Bonus Rewards Allocated.
["Some are forged through fire. Others through will."]
~----~
Kairo collapsed backwards, eyes burning, heart hammering in his chest.
Later, as the team limped toward the next zone, Mira walked beside him silently.
Then, "You're insane". She muttered.
He didn't reply.
She nudged him. "…Thanks. For saving me".
He grunted.
"…What's your name again?"
"Kairo Vale".
She nodded slowly. "Well, Kairo… I think you just passed your first threshold".
He blinked.
"…What threshold?"
She grinned. "Exactly".