But that wasn’t all.

    RUMBLE RUMBLE RUMBLE!

    As the ground trembled violently, a sound began to rise in the distance—a sound like crashing waves.

    The sound wasn’t that of ocean waves breaking on the shore.

    This was “acid”—the corrosive kind found in hydrochloric acid.

    That’s why this place was called the Swamp of the Mountain.@@@@

    Su-ho scanned his surroundings.

    There was no place to run.

    No place to hide.

    No matter how fast someone might be, no one could outrun a deluge of liquid flooding in.

    The tide of acid surged toward Su-ho.

    CRASHHHHH!

    The wave filled the cavern completely.

    There was nowhere to escape.

    The deluge lasted several seconds before gradually receding, leaving the floor exposed once more.

    The surroundings fell silent.

    And in the wake of the acid wave, something new appeared—a massive red basalt rock, towering as high as a person.

    It stood there like a boulder, though it hadn’t been visible before.

    Then, the red basalt began to squirm.

    Much like gelatin shifting and wobbling, it started to take on the shape of a person.

    Its transformation continued, resembling a combat suit worn by soldiers.

    The transformation began at the feet, gradually covering the legs, torso, and finally moving up toward the head.

    But what emerged where one might expect a helmet wasn’t a featureless mask.

    It was a human face.

    Su-ho’s face.

    Encased in the red suit, Su-ho revealed only his face and muttered, “Phew, the smell...”

    He wrinkled his nose in disgust—not because of the overwhelming tide of acid, but because of the stench that accompanied it.

    No wonder.

    The “acid” flooding the Swamp of the Mountain wasn’t hydrochloric acid. It was gastric acid, the digestive fluid secreted by stomachs—stomach acid.

    Su-ho glanced again at the spot where he had stabbed the wall earlier with his Blood Sword.

    The surface wasn’t a typical rocky cave wall but resembled the flesh of a living creature. The "wall" had split, revealing muscular tissue oozing with blood.

    Nodding to himself, Su-ho remarked, “It’s been a while since I’ve seen a gut-themed gate.”

    A gut theme.

    That’s exactly what this was.

    The Swamp of the Mountain wasn’t an ordinary cave but rather the interior of a colossal living organism.

    That explained the wave of stomach acid and the anguished scream that had echoed through the cavern when Su-ho stabbed the wall.

    For any living creature, pain in the intestines was particularly excruciating.

    As Su-ho surveyed the ceiling, he thought to himself, “This must be inside a Mega Worm, right?”

    The Mega Worm was a type of worm-like monster known for its characteristic ability to grow endlessly through feeding.

    That’s why a gate with this kind of theme had formed.

    When a creature becomes too massive, its interior can be perceived as a battlefield from a certain perspective, thus qualifying it as a gate.

    For this reason, the skill Su-ho had shown Jeong Cheol-min as justification for choosing this gate was his Blood Weapon.

    The stomach acid of a Mega Worm was potent enough to dissolve even the most robust equipment. Many players had met their ends here, their gear and bodies alike reduced to nothing.

    However, Su-ho’s Blood Weapon wasn’t made of ordinary metal. It was a manifestation of his mana, shaped from his very blood.

    Thus, the stomach acid of a mere overgrown worm couldn’t harm it.

    “Well, if there’s a massive stat gap, even I could be completely dissolved.”

    Fortunately, Su-ho’s red-grade mana provided ample protection.

    Based on Su-ho’s knowledge, the Mega Worm’s level was at most around the 1-star mark, far from threatening to him.

    Having completed his initial survey of the area, Su-ho manipulated his Blood Weapon to extend and cover his entire face.

    This wasn’t because he particularly enjoyed wearing a helmet but because he had no desire to endure the stench of stomach acid directly.

    “Alright, time to move forward.”

    With his equipment secured, Su-ho began walking deeper into the Swamp of the Mountain.

    ***

    – KUUOOOOOOHH!!

    CRASHHHHH!!

    The tide of acid surged once more.

    But Su-ho didn’t dodge or retreat.

    Tanker and healer.Tanker and tanker.Tanker and mage.Mage and healer.Mage and mage.Even healer and healer.

    “I wonder what form it will take when it evolves?”

    Su-ho looked around as he pressed forward.

    “Still, this Mega Worm is holding out longer than I expected.”

    The Swamp of the Mountain was a sealed gate but not entirely unexplored.

    While it had no entry-level restrictions, it was eventually cleared in the distant future by two heavily armored tankers who managed to overcome its challenges.

    Thus, Su-ho already knew the general method for clearing this gate.

    “The key is to push the Mega Worm to its limits until it forcibly ejects me from its body.”

    No creature could tolerate having its internal organs repeatedly stabbed.

    The strategy was simple yet effective: continually provoke the Mega Worm by attacking its insides until it had no choice but to expel the player.

    To achieve this, Su-ho had sharpened his shoes and kept stabbing relentlessly.

    In the past, those tankers who cleared this gate reported that moving around and spreading out the attacks caused more irritation than targeting a single spot repeatedly.

    Once again, the Mega Worm roared.

    – KUUOOOOOOHH!!

    CRASHHHHH!!

    Another wave of stomach acid surged forward.

    Su-ho, accustomed to this by now, reversed his grip on his sword and drove it into the wall, anchoring himself securely.

    The next wave of acid engulfed him entirely.

    THUD!!

    A heavy impact.

    Something collided with Su-ho.

    He couldn’t see it.

    The waves of acid were murky and opaque, making it impossible to see anything during the surge.

    Even with the Original Vampire Effect, which negated the disadvantages of darkness, Su-ho couldn’t overcome this visibility issue.

    “What was that?”

    Was it a Parasite?

    It wasn’t uncommon for Parasites to be swept up by the acid waves and collide with him.

    Judging by its size, it seemed plausible.

    Gripping the embedded blood sword with his left hand, Su-ho summoned another blood sword into his right hand.

    [ Steel Slash Activated. ]

    SLASH!

    The blade connected with a heavy, solid resistance.

    Su-ho was certain he had cut something.

    Yet no system notification appeared, meaning he hadn’t defeated an enemy.

    The system’s alerts worked regardless of visibility, so the absence of a notification was unusual.

    When the acid wave finally subsided, Su-ho saw it.

    “Hmm?”

    As the acid drained away, something remained on the ground ahead of him.

    A shriveled, desiccated form.

    It was large.

    Half of it had been cleanly severed, with the other half presumably carried away by the acid tide.

    “What is this?”

    Curiosity piqued, Su-ho halted his movement to examine it closely.

    Ordinarily, he would have ignored it and continued forward, but he had been exploring this place for quite some time and had never seen anything like it before.

    His eyes widened in recognition.

    “This...!”

    The object before him was shriveled and hardened, making it difficult to identify at first glance.

    But Su-ho knew exactly what it was.

    It was a Body Worm (Chechung)—a creature that lived inside the Mega Worm’s body.

    “A Body Worm? There are Body Worms here? But why does it look like this?”

    Body Worms were not pests but symbiotic organisms that lived harmoniously with massive creatures like the Mega Worm.

    They served as internal caretakers, much like the relationship between crocodiles and plover birds.

    Su-ho had encountered Body Worms before.

    In the mid-to-late stages of the Great Cataclysm, gates featuring massive creatures with interior-themed environments often appeared.

    In such cases, the guardians were usually Body Worms rather than external Parasites.

    Surveying the shriveled Body Worm and the countless Parasites around him, Su-ho finally realized the true nature of this gate.

    “The main objective isn’t the Mega Worm itself.”

    The true focus of this gate and its ultimate challenge lay in eradicating the Parasites that had overrun the Mega Worm’s body.

    The Swamp of the Mountain’s real conquest lay not in defeating the host but in purging its invaders.