My Monster Evolution in One Punch Man

BOOM!!!

The deafening explosion tore through the vast underground chamber, shaking its foundation as shards of stone rained down like a storm from the crumbling ceiling. A burst of blinding white-blue light erupted with the blast, engulfing the Slime Octopus's massive body and washing over every monster's eyes in a flood of searing cyan. A savage shockwave followed almost instantly, ripping through the space with brutal, unstoppable force.

Several wolf-level monsters, who had been loitering around to watch the spectacle, were hurled through the air like brittle leaves in a hurricane. Caught completely off guard by the overwhelming energy discharge, a few unlucky ones slammed into the rock walls with devastating impact, bones fracturing, skulls cracking wide open, blood splashing in all directions.

Screams and agonized howls echoed throughout the chamber, mixing with the barely audible, muffled noises of monsters sneaking bites and greedily swallowing scraps in the midst of the confusion.

[Tiger-level monster "Slime Octopus" eliminated. Gained 28 Origin Points!]

A crisp system prompt rang out in Hansen's mind, confirming the creature's demise. As expected, the stronger the monster, the more Origin Points it dropped upon death. This mid-tier tiger-class octopus alone had yielded over ten times the points of those weak, wolf-level cockroach beasts.

As the scalding steam and smoke from the explosion gradually faded, a tall figure clad in fearsome black armor emerged from the heart of the blast zone. Hansen calmly flicked away the mixture of blue blood and brain matter clinging to his claws, as if he had merely swatted a gnat. His cold eyes swept across the chamber like a ruler inspecting his conquered land.

Silence.

Only moments earlier, the underground lair had roared with chaos and noise. Now it was swallowed in absolute, suffocating quiet. Nearly all the remaining monsters lay sprawled on the ground, bodies shaking uncontrollably, barely able to breathe under the weight of fear. In their eyes remained nothing but awe and primal terror in the face of overwhelming might.

Even the tiger-level monsters were drenched in sweat, heads lowered in submission, their bodies still as stone. None dared to move.

In only a few brutal exchanges, he had eradicated a beast they had once believed to be untouchable.

The scene was soaked in blood yet charged with reverence, completely upending their understanding of the balance of power.

Hansen found the result satisfying.

Establishing dominance had to be absolute and brutal. That was the only way to avoid future trouble and endless challenges.

He stepped toward the center of the impact zone, where the ground beneath his feet had been scorched into a deep, blackened crater. At the bottom, only a few charred, grotesque remains were left behind, nothing more than twisted chunks of what had once been the Slime Octopus.

With a claw, Hansen casually lifted the largest hunk of burnt flesh. It was roughly half a meter long, still faintly recognizable as part of a tentacle, and smoked with curling black fumes.

Weighing it in his hand, he turned toward the monsters around him, all frozen in place by terror, and asked, "Anyone know where this thing's room is? Whoever leads me there gets this."

His voice cut through the silence like a blade.

The monsters exchanged wary glances, fear clearly etched into their faces, yet none could fully suppress the glint of greed flickering in their eyes. The Slime Octopus was dead, true, but it had still been a tiger-level monster. Its flesh remained an incredibly potent energy source, especially valuable to weaker creatures.

"M-Me! Sir, I know!"

After a short silence, a rat-like wolf-level monster suddenly squeaked out, lifting a trembling paw. Its voice cracked with a blend of terror and excitement. "Sir! I-I know where that bastard Slime Octopus's room is! I can take you there right now!"

The creature was small and frail, its dirty gray fur sticking out at odd angles, ragged and unkempt. Though its body quivered, its eyes were locked onto the scorched chunk of corpse in Hansen's hand with unhidden, ravenous desire.

"Good. Lead the way."

Hearing that, the rat monster's eyes gleamed with triumph. Without hesitation, it scurried forward on all fours, tail twitching as it eagerly led the way. Hansen followed calmly behind, his tall, armored frame gradually disappearing into a small, unremarkable side tunnel beneath the watchful, trembling, and envy-filled gazes of the monsters left behind.

Only once that terrifying figure had vanished completely into the shadows did the crushing pressure in the chamber begin to ease. The monsters exhaled as one, some collapsing to their knees, but almost immediately, a fresh surge of jealousy and greed ignited in their eyes, burning hotter than before.

"Damn it! That rat..."

"He killed Boss Octopus and snatched all the spoils!"

"Shhh! You trying to die? Did you not see what happened to Boss Octopus?"

"One hit. One damn hit and he was gone! That guy's not some random freak... he's a monster."

"No shit, Sherlock, we all are!"

Hushed murmurs rippled through the chamber, filled with resentment and frustration, but they quickly faded into uneasy silence. No one dared speak too loudly. After all, the strongest monster in the entire zone, Slime Octopus, had just been vaporized, reduced to nothing but blackened chunks of meat.

Even if they had a hundred times more courage, none of them had the guts to challenge the monster who did it.

…

After weaving through a winding network of dim, damp underground tunnels, Hansen followed the rat monster to a secluded heavy door.

"This is it, sir!"

Worried Hansen might doubt him, the rat wiped sweat from his grimy brow and quickly explained, "My ability is digging tunnels. I know this whole terrain like the back of my paw! I once hid underground and saw Slime Octopus enter through this passage myself. This has to be the room!"

Hansen gave a slight nod. Without hesitation, he raised his fist and slammed it into the locked door.

BOOM!!

A shockwave exploded outward as his raw physical strength surged in an instant. The rat monster was blown backward, sent tumbling head over heels by the force. The thick iron door at the center of it all twisted with a horrible screech and cracked cleanly in half.

The path ahead was now open. Hansen stepped into Slime Octopus's lair.

The interior had been remodeled into a wide, uneven cavern. The floor was damp and coated in sticky muck that squelched loudly underfoot. Every step echoed with a wet, nauseating sound. The walls glistened with translucent slime, some of it slowly dripping in long, shiny strands.

In one corner, bones were piled without care alongside shredded human gear and several half-rotted small monster corpses. Emergency snacks, no doubt.

Hansen's gaze shifted to several wooden crates stacked near the far wall. They immediately caught his attention. His instincts told him these were exactly what he had come for.

Slime Octopus had been responsible for distributing food and supplies, yet he was infamous for hoarding the rewards intended for lower-ranked monsters. It made sense that he'd have a secret stash, and judging by the lair's grotesque interior, it matched the creature's greedy personality perfectly.

Hansen casually lifted the charred hunk of octopus flesh and tossed it over his shoulder.

"For you."

"Thank you, sir! Thank you so much!"

The rat monster caught the smoking meat with both claws, trembling as though he'd been handed a priceless relic. Without waiting for it to cool, he opened his fanged mouth and tore off a massive chunk, gulping it down with an audible, gluttonous swallow.

A moment later, mid-chew, he froze. Realizing Hansen was still watching, cold sweat broke out on his already filthy face.

Hansen asked offhandedly, "What's your name?"

Startled, the rat monster snapped upright. "Sir, my name is Fang!"

"Got it. Now take your food and get lost," Hansen said, already turning away and striding toward the suspicious crates at the back of the den. With a dismissive flick of his hand, he added, "Try not to die."

"Y-Yes! Understood! Thank you for the warning, sir! And the reward!"

Realizing he'd been spared, Fang nodded so hard his head blurred, then bolted for the cavern wall. Still clutching the half-eaten meat to his chest, he began tunneling rapidly into the stone. Within seconds, he disappeared completely, even sealing the entrance behind him with packed dirt and rock, leaving no trace behind.

Hansen didn't glance back. His Beast Instincts had already tracked Fang's every move with precision. For a wolf-level monster, the rat had shown decent intelligence and a clear survival instinct. Hansen hadn't intended to silence him. Creatures like that could prove useful in the future.

He turned his attention back to the crates and strode forward. With one strong kick, he shattered the lid of the nearest rotting box.

Inside, packed tightly and stacked in layers, were clusters of dark red, fleshy lumps. Each was riddled with thick veins and twisted muscle fibers. Even after prolonged storage, they pulsed faintly, thumping like recently harvested organs, their rhythm disturbingly lifelike.

They were Monster Cells.

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