This F-Rank Bubble Mage Is Too OP!

Chapter 70: E-Rank Dungeon Boss (Part-3)



Swamp Eaters.

The name alone was enough to make veteran Hunters frown. There were many variations of them—monsters shaped by the environment they had claimed as their lair. The most common kind was the typical mud-bodied Swamp Eater, a lumbering predator born from the thick sludge of stagnant marshlands. Others were far more dangerous—made of water so foul and dense it was nearly a liquid prison; made of fire, igniting the bog around them into burning tar pits; even made of molten rock, their cracked hides leaking streams of lava that could boil a lake dry.

But no matter their form, they shared one trait: they preferred to remain submerged beneath their chosen swamp, undisturbed, patient as the grave. They could lie there for years, decades even, letting their presence poison the land above.

That poison was unmistakable. The life around a Swamp Eater's lair withered into desolation. Trees turned skeletal, their bark flaking like rotting skin. The soil hardened and cracked, unable to nurture even the most stubborn weed. The air hung thick with decay, heavy enough to sting the lungs. And always—always—there were the carrion feeders: zombies, ghouls, lava golem, or worse, drawn to the death the Swamp Eater radiated.

Looking at the state of this E-rank dungeon—the endless graveyard of blackened trees, the ground like scorched parchment, the Rotlings wandering aimlessly—River realized how obvious it had been. Of course the Dungeon Boss was a Swamp Eater.

In the original timeline, he had killed many of them. Though "killed" barely scratched the surface—those battles had been apocalyptic in scale. Back then, he had already reached his max level of fifty, and the Swamp Eaters he faced were the kind that could level a city in a single stomp or erase a mountain ridge simply by charging through it. They were walking disasters, calamities disguised as swamp-born nightmares.

And yet, despite his level cap, River had stood toe-to-toe with them—because of his greatest asset: his mana control and imagination. Those alone had let him punch far above his weight, to fight like someone at level eighty or higher.

But now… now he was only level twenty. And standing in front of him was a monster that could crush even an overconfident mid-tier party.

The water—or rather, the black, boiling muck—of the swamp began to churn. A low, gurgling sound rumbled from beneath the surface, the kind that crawled along your spine and made your gut tighten in warning.

Then it emerged.

A massive, grotesque form surged upward, sending waves of sludge splashing across the shore.

The monster's every movement seemed slow and heavy, but he knew better—it wasn't sluggishness, it was the deceptive pace of something that had no need to rush. Something that believed it was inevitable.

The ground trembled under its weight as it took a step forward, tar dripping from its foot and leaving bubbling craters in the soil.

It opened its mouth.

What came out wasn't a roar—it was an eruption. A guttural, vibrating bellow that made the air shake and the swamp's surface ripple violently. The shockwave slapped against River's chest, and his hair and clothes were tossed into disarray.

Unlike the first roar it let out the moment it came out, this roar felt like a slap, a declaration to his face.

"Ah! That stink—" River gagged, covering his nose and grimacing. "Every damn time…"

He had faced Zombie Swamp Eaters before, but that smell—the rancid blend of decay, swamp gas, and molten tar—was the one thing he could never get used to. Even his enhanced vitality didn't spare him from the sensation of his stomach twisting in revolt.

This time, however, was different. He is back at the bottom, facing something that could swat any E-Rank Hunters into paste if they are careless.

Still… his lips curled into a smirk.

So what?

This was his second chance. If anything, fighting something like this at such a low level was exactly what he needed, to push his limits. And besides, considering his Stats along with his Mana Control, this fight might not even be compared to the Quest inside that Awakening Dungeon.

Holding his breath, River flicked his wrist.

The conjured Bubble Bombs flew toward the Zombie Swamp Eater like glimmering bullets—silent, fast, and unnervingly precise. The instant the first bubble touched the monster's rotting hide, the chaotic mixture of compressed mana and condensed air inside detonated with a pop that was anything but harmless.

BOOM! BOOM! BOOM!

Each impact burst into a violent, localized explosion, tearing at the already unstable flesh of the beast. Strips of rancid skin and hunks of decayed muscle flung outward, splattering the swamp shore in slick, black ichor. The tar-like liquid hissed and steamed where it hit the ground, leaving angry, bubbling craters in the dirt.

The Swamp Eater staggered back two heavy steps, each one sending a tremor through the earth. Its roar ripped through the air—a sound like a hundred dying voices screaming in unison.

"Good," River muttered, lips curling into a small, dangerous smile. He hadn't even used his full strength.

That was the trap most low-level Hunters fell into—pouring all their power into the opening strike. River had learned the hard way, in his first life, that restraint was just as lethal a weapon. If he poured everything into a single Bubble Bomb right now, he might bring the monster to its knees… but then he'd be left with an empty MP pool and a death sentence.

He was back at the bottom, forced to be smarter than his stats. Every move had to be calculated.

Still, part of him burned with curiosity. This was his first real test since hitting level twenty. His new build was still unfamiliar in combat—he needed to know what it could really do.

River gripped the hilt of his D+ Grade Steel Dagger, bent his knees, and exploded forward. Mana surged into his legs, and the world blurred. In less than a heartbeat, he was in front of the Swamp Eater's massive, rotting face.

The dagger itself wasn't impressive against hard armor or tough carapaces—but against soft, rotted flesh? It could slice deep. That was the plan.

Unfortunately, his opponent wasn't as mindless as it looked.

River's instincts screamed in warning. The hair on the back of his neck stood up, honed reflexes from years as the Last Hunter telling him death was a danger away.

Without hesitation, he conjured a bubble barrier to surround him.

A split second later, a jet of boiling tar-like sludge erupted from one of the gaping wounds in the Swamp Eater's chest. The pressurized blast hit the barrier with the force of a battering ram.

BANG!

River was hurled backward, the bubble carrying him like a rolling shield. His body smashed through the skeletal remains of the forest, snapping dead trees like brittle twigs. The ground cracked beneath him when he finally landed, sending up a cloud of dust and splinters.

As the haze cleared, his silhouette came into view.

Still standing.

Still inside the bubble—its shimmering surface quivering from the impact but holding strong.

River's expression hadn't changed. No fear. No panic. Just quiet calculation.

"Hmm… definitely worthy of a few groups of E-rank Hunters," he muttered under his breath. His voice was calm, but his eyes never left the monster. He could feel the pressure of its presence—a predator's focus on prey it had already decided was its next meal.

He flexed his fingers around the dagger's hilt, feeling the faint pulse of his strength. He had copied the build of a Physical Class Hunter but the difference was glaring—his strikes were faster, but not fast enough.

If he had been a true Physical Hunter of the same build, his opening attack would have landed before the Swamp Eater had a chance to counter. That fraction of a second was the difference between carving into the monster's head and being launched halfway across the dungeon.

"I still have a long way to go," River murmured.

But his smile told a different story. It wasn't disappointment—it was excitement.

His legs tensed, and the ground cracked beneath his boots as he pushed off. He became a blur once again, darting between the shattered trunks of the dead forest. This time, his path wasn't direct. He weaved left and right, changing his angle of approach every few meters, keeping his movements unpredictable.

The Swamp Eater turned to follow him, its pale-yellow eyes rolling lazily but tracking him all the same. Another roar escaped its maw, and three fresh jets of boiling sludge blasted outward in rapid succession.

River slipped past the first, ducked under the second, and conjured a half-sized bubble to intercept the third. It popped instantly upon impact, but the burst absorbed enough force to let him slide through unscathed.

Mana surged again as he closed the final gap, leaping high.

He didn't aim for the head this time. Instead, his dagger sliced downward toward one of the crater-like wounds on the creature's shoulder. The steel sank deep into rotted flesh, cutting until it met bone.

The Swamp Eater shrieked, lurching sideways in an attempt to swat him away. River wrenched the dagger free, flipping backward midair, and threw a trio of small Bubble Bombs in a tight arc toward the fresh wound.

They detonated point-blank.

Chunks of foul meat exploded outward, and a flood of boiling tar poured from the gaping hole. The monster staggered, one knee sinking into the swamp.

River landed lightly on the far side, dagger still in hand, already moving. He could feel his mana reserves starting to decrease like water from well.

But with one use of Mana Gathering, they began to rise, not fast as he's still in combat but good enough for his MP not to go below 70.

As he ran, Bubbles formed around him and if one looks closely, they will notice that something is different about them.

"Time to test out my second ability!"


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