System Mission: Seduce the Strongest S-Class Hunters or Die Trying!-Chapter 129: [KAIRO’S SWORD]

"Not on my watch." Kairo’s words were little more than a growl, lost beneath the cavern’s shriek, but Eli heard them.

His eyes blew wide.

It felt like time fractured into fragments—every heartbeat dragging slow and heavy, as if the world itself was waiting to see what Kairo would do.

Then Kairo moved.

His stance was perfect, obsidian blade angled high, aura coiled tight around him like a predator ready to strike. But instead of cutting forward—his free hand turned. His wrist twisted with deliberate intent.

And he cut.

The black edge of his blade tore across his own wrist. Flesh split open in one brutal stroke.

"K—!" Eli’s breath locked, horror jolting through him sharper than the pain splitting his skull. His yellow eyes widened, glowing faint through the haze. "K...Kai—"

Scarlet burst free.

Hot. Violent. It sprayed across Eli’s cheek, warm rivulets running down his pale skin.

The copper tang of blood filled the air, heavy and suffocating.

Eli’s chest convulsed, trembling against Kairo’s arm. "Kairo..." The name tumbled out, weak and broken, half a plea, half disbelief.

’He’s...he’s taking too much blood from himself.’

But Kairo’s voice cut through the chaos, cold and absolute, as if his body wasn’t unraveling.

"—Pulse Burst."

The blood detonated.

Scarlet pressure erupted outward like a bomb, a concussive blast slamming through the cavern.

The tentacle diving for Zaira and Mio was torn open mid-strike, shredded as if a thousand invisible blades had ripped across its surface.

The force rocked the cavern violently. Water blasted backward in violent waves, spraying across jagged stone.

Zaira stumbled, shielding her face with one arm, teeth gritted against the shockwave. Beside her, Mio collapsed to one knee, threads flickering in panic before falling slack again.

The tentacle recoiled with a guttural crack, thrashing back toward the ceiling. Flesh sizzled, glistening as blood poured in heavy sheets.

But another one was already descending.

A second limb slammed down toward Kairo and Eli, cutting through the air like a falling guillotine.

Kairo didn’t hesitate. His obsidian blade screamed as it swept upward, scarlet aura flaring alive along its edge. The collision shook the cavern. Sparks hissed as steel carved flesh.

The strike didn’t meet armor. Didn’t meet bone.

It was only flesh.

The black blade carved through clean, slicing deep into sinew and muscle. The tentacle tore back with a guttural screech, severed strands of meat spraying across the water below.

Above, the octopus writhed, dozens of glowing eyes pulsing furiously. The cavern shook with its rage, stone cracking from the vibrations.

Kairo’s voice cut through it all, sharp as thunder.

"Mio!"

The disoriented hunter jerked, wide eyes snapping upward. His chest heaved, breath ragged, threads twitching faintly but still tangled and limp.

Kairo’s tone didn’t soften. Couldn’t. It was a command honed by fire, a blade meant to cut through hesitation.

"Have you finally come to your senses?!" His voice slammed into the cavern heavier than the monster’s shriek. Black eyes blazed with fury. "Get your act together—our whole team is in danger!"

The words struck harder than the tentacle had.

Mio’s chest rose once, faltered, then steadied. His trembling hands curled into fists, silver threads vibrating in the air. His unfocused gaze hardened, faint light flickering in his eyes.

’Oh.’

Much to everyone’s relief—especially Eli’s—the shrieking stopped. 𝑓𝓇𝘦ℯ𝘸𝘦𝑏𝓃𝑜𝘷ℯ𝑙.𝑐𝑜𝓂

The oppressive screech that had been tearing his body apart finally silenced.

The ringing in his ears dulled to a faint hum. The crushing waves of danger receded, like a tide pulling back from shore. For the first time in what felt like hours, Eli’s chest loosened.

His body sagged weakly against Kairo’s arm, blood still slick on his skin, but his breathing steadied. His danger sense... was quiet.

Relief stirred in his chest, fragile, fleeting. But Eli knew better. He didn’t dare relax.

Beside him, Mio stirred fully. His body still trembled, his face pale with exhaustion, but at last his voice rasped out.

"I... I can help." The words were heavy, slurred, but his silver threads quivered faintly back to life in the air. His wide eyes swept the cavern, disoriented. "What... what happened?"

’You tried to kill me... a lot.’ Eli almost laughed through the blood caking his lips, a bitter cough rattling out of him instead.

He wanted to joke, to spit some half-hearted retort—But of course, the silence didn’t last.

"—It’s regenerating!"

Zaira’s sharp gasp cut the air.

"R-Regenerating?" Eli’s head jerked up. His vision swam, but he forced his yellow eyes to focus through the blur.

Kairo looked.

Mio looked.

And all of them saw it.

The octopus writhed, its massive bulk pulsing as the torn flesh bubbled grotesquely. Its wounds didn’t bleed—they seethed. Thick, translucent fluid oozed across its body, weaving black sinew back together.

The gashes Kairo had carved were knitting closed, raw muscle stitching itself with unnatural precision, as though time itself bent to its will.

The cavern trembled again. Stone cracked overhead and rained down in gritty sheets.

Eli’s danger sense spiked violently—lancing through his skull like a hot knife. His vision whitened, his breath hitched sharp. "D-Danger—it’s coming!"

Kairo coiled immediately. His stance widened, obsidian blade raised high. Scarlet aura flared across the cavern walls, jagged light cutting through the dark. His black eyes locked on the ceiling, steady, cold.

Mio braced beside Zaira now. Still shaking, but upright, threads vibrating in arcs of silver that hummed with restrained force. Zaira planted her feet, her dagger gleaming, aura shimmering faint pink along her skin.

The cave split with a violent crack, the sound like bone breaking against stone.

Eli’s senses screamed hotter, sharper, dragging his focus toward the strike before it even descended.

"There!" he rasped, voice shredded but urgent as his trembling hand pointed upward. "Kairo—it’s aiming for you!"

The captain didn’t hesitate. His obsidian blade swept a perfect arc, aura bursting bright along its edge.

The tentacle dropped. Massive. Writhing.

Kairo’s strike met it head-on.

Steel pierced flesh.

Eli braced for the spray of ichor, the echoing screech. He expected Kairo to wrench his blade free, to cut again before the monster regrouped.

But nothing went the way it should.

The danger sense stung differently. Sharper. Wrong.

’Wait—what?’

The danger wasn’t radiating from the octopus anymore.

It was coming from Kairo’s sword.

Eli’s head snapped up, bloodied lips parting in panic. "Kai—!"

Kairo’s expression shifted, a flicker of shock cracking his mask of calm. His obsidian blade was buried deep into the tentacle—yet when he pulled, it didn’t move.

It was stuck.

No—worse.

The flesh rippled, muscles constricting, suction ridges locking around the blade. Inch by inch, the monster swallowed the steel, dragging it deeper into its body like it was devouring prey.

For the first time, Kairo’s black eyes widened.

"...What?"