The underground cave before me was filled with a strong smell of sulfur.
The area around Baekrin's Horn was a volcanic region, and hot springs were common.
However, the heat radiating from this place was incomparable to the main mountain where Baekrin's Horn was located.
It was scorching hot.
Jin Cheon-hee took out a towel he had prepared in advance and soaked it in medicine.
It was something to block the rotten egg-like smell of sulfur.
Wrapping the towel around his face like a mask, he took a step forward.
Hwanggu, his dog, barked and stood in front of him.
"Hwanggu, no. It's too hot for you."
Woof!
Jin Cheon-hee patted Hwanggu's head and then squeezed his body into the narrow underground cave.
"Keep watch around here until I come back."
Woof, woof!
Hwanggu licked Jin Cheon-hee's hand and then sat down on the ground.
Jin Cheon-hee chuckled at the sight of Hwanggu.
How far did he push his body down? His feet didn't touch anything.
Jin Cheon-hee gathered his courage and jumped down.
Thud—his feet hit the ground.
Looking up, he could barely see the light from the surface through the ceiling.
It seemed like it would be difficult to find the exit once night fell.
Woof!
"Yes, Hwanggu. When I give the signal, bark."
Woof, woof!
Fortunately, Hwanggu was outside, so Jin Cheon-hee could follow the sound of his barking to find his way back.
Heat rose from the ground.
"Is it hard to breathe?"
Jin Cheon-hee immediately circulated his Five Elements Divine Technique to resist the heat.
As he began to circulate the ice energy from his dantian, his body quickly cooled down, and his dizziness subsided.
"I should try circulating fire and water energy here when I have time. It seems like I could gain something from it."
Most martial artists would never even think of doing such a thing.
If the energy circulation were to be interrupted, it would be extremely difficult to maintain consciousness in the heat.
But Jin Cheon-hee thought that such extreme situations were the perfect opportunity to advance his internal energy.
"That's right. I'm young. It's only natural to push this young body to its limits."
Young.
Full of potential for growth.
So, he couldn't afford to waste this time.
Since he could prevent illness with his medical skills, it was better to keep pushing himself and training without rest.
It was a thought only possible because this was his second life.
"Alright. I'll keep circulating the ice energy until I find the underground pond."
The ice energy of the Five Elements Divine Technique was a combination of water, metal, and earth.
It was a rather tricky attribute.
But perhaps because he had undergone a body transformation, the energy of the five elements moved and combined on its own, flowing through his meridians without him having to consciously control it.
"I didn't expect this."
It was as if the five elements had a will of their own, moving to protect his body.
Jin Cheon-hee was inwardly surprised by this unexpected ability.
Moreover, the energy of the five elements, which was already pure, had become even purer.
He could fight the heat with less internal energy.
How much further did he go? He saw a pond made of hot spring water.
It was boiling so fiercely that an ordinary person would suffer full-body burns in less than a moment.
"Just like in the novels."
Periodically, this hot spring water would erupt through the underground cave to the outside.
That's how hot it was inside—comparable to hell.
Jin Cheon-hee took a deep breath.
"It's okay. I can do this. I even took the Xianyuan Five Elements Divine Pill to get through this."
If his master had seen this, he would have called it madness and dragged Jin Cheon-hee out by the scruff of his neck.
Jin Cheon-hee closed his eyes and focused on his internal energy.
He continued to circulate the ice energy through his dantian.
Normally, the cold energy would slow his heart, but here, it was just enough to block the heat.
"It needs to get colder. And it needs to push deeper."
He focused on sending his internal energy through all his meridians.
His body gradually grew colder and slower, as if he were descending into hypothermia.
A headache began to press in.
With great effort, Jin Cheon-hee dipped his hand into the underground hot spring.
The boiling water warmed his frozen body.
But it was only for a moment—soon, the heat of the hot spring and the ice energy of the Five Elements Divine Technique began to clash.
Jin Cheon-hee adjusted the Five Elements Divine Technique to maintain balance.
Finally, he submerged his entire body.
Splash!
"Phew!"
As soon as he felt it was manageable, he unleashed a grappling technique he had learned from the Zhuge Library.
Ten Thousand Jin Hammer.
His body became as heavy as a thousand jin, sinking deeper and deeper into the water.
The further down he went, the hotter the temperature became, and the stronger the current grew.
Jin Cheon-hee maintained the Ten Thousand Jin Hammer.
Boom—
Finally, his feet touched the bottom of the water.
Jin Cheon-hee took out a Night Pearl.
It was larger and brighter than a normal Night Pearl.
He had obtained it from the ceiling when he helped Hwanggu in the past, never imagining he would use it like this.
The Night Pearl illuminated the surroundings, allowing him to secure his vision.
Jin Cheon-hee moved forward.
How far did he go? He discovered a creature that resembled a crayfish.
Even in this intense heat, life existed.
He had read about it in books, but seeing it in person was astonishing.
Jin Cheon-hee caught it and tied it with a strand of hair.
Minor Summoning Technique.
A simple command technique for small animals.
The command Jin Cheon-hee gave was:
"Take me to where the most fearsome creature lives."
The crayfish-like creature shivered once and then began to crawl in a certain direction.
Jin Cheon-hee followed it.
How long did he walk? The crayfish stopped.
It meant they had arrived.
As soon as he released the Ten Thousand Jin Hammer, his body shot upward like a diver releasing a weight.
"Phew!"
When he surfaced, a massive underground lake came into view.
Jin Cheon-hee felt his body cooling rapidly and withdrew the ice energy.
Cold water brushed past his fingers.
"Just like in the novel. Only here is the water cold."
It matched the description of the pond where the Ten-Thousand-Year Fire Carp lived.
"I would never have found this if I hadn't read the novel. No, I wouldn't have found it without Hwanggu either."
Jin Cheon-hee took out a metal rod from his pocket.
Assembling it according to the seams, it became a spear.
"I'll catch it with this!"
Ten-Step Divine Spear!
When dealing with small fry, it was fine to fight bare-handed.
But the Ten-Thousand-Year Fire Carp was the real deal.
To face this creature, he had to risk his life.
Jin Cheon-hee secured the Night Pearl more firmly to his waist.
"I am the bait."
In this underground lake, in the pitch-black darkness, the only thing glowing was the Night Pearl.
It was obvious that the Ten-Thousand-Year Fire Carp would attack the light.
The problem was that this was an underwater battle.
Jin Cheon-hee unwound the Black Heaven Blood Thread from the bracelet on his wrist and tightly wrapped it around the spear shaft.
The pre-twisted Black Heaven Blood Thread resembled a rope.
"Thank you, Heavenly Demon Brother!"
He never imagined he would use Yeha Ryun's gift like this.
Then, he closed his eyes and floated in the water, focusing on his feet.
How long had it been? Something slippery brushed past his toes.
It felt hot and hard.
It was the fin of the Ten-Thousand-Year Fire Carp.
The creature brushed past him.
It seemed to be judging whether Jin Cheon-hee was food or not.
And then, after a moment, the water surged.
Looking down, he saw the creature's gaping mouth rushing toward him.
Jin Cheon-hee quickly swung the spear to stab it.
At that moment, he couldn't even see how it moved.
The creature's tail struck him.
Thud!
Jin Cheon-hee's body floated up to the surface.
Just one hit, and his insides felt like they were being torn apart.
He felt like he might lose consciousness.
"I've seen orcas play with seals like this!"
They would hit the seals with their tails, sending them flying out of the water, and when the seals were stunned, they would eat them.
The creature was quite intelligent, as expected of a spiritual beast.
Jin Cheon-hee's body, floating in the air, crashed back into the water.
And there, the mouth of the Ten-Thousand-Year Fire Carp was waiting.
Even a skilled martial artist would be finished the moment they entered that mouth.
Jin Cheon-hee recalled the mantra of the Ten-Step Divine Spear, the Illusory Thunder Spear, and thrust the spear downward.
Illusory Thunder Spear.
Thunderbolt Strike!
Blue lightning surged from Jin Cheon-hee's dantian and gathered at the tip of the spear.
Fortunately, the creature was careless at this moment! If it knew Jin Cheon-hee's true strength, the fight would be over.
No matter how skilled Jin Cheon-hee was, he wasn't a protagonist like Yeha Ryun.
He couldn't maintain a crazy underwater martial arts battle with a fish for long.
So, he had to end it in one strike.
The blue lightning at the tip of the spear began to grow thicker.
But suddenly, the Ten-Thousand-Year Fire Carp tried to close its mouth.
"Damn it! It's quick to notice."
Jin Cheon-hee shot the spear into the creature's mouth before the lightning could fully gather.
Sssshhh—!
The spear pierced the roof of its mouth.
The creature began to resist in pain.
The entire lake shook.
Jin Cheon-hee swam toward the edge of the lake, unwinding the Black Heaven Blood Thread.
As the Ten-Thousand-Year Fire Carp moved, the thread began to unravel quickly.
As soon as Jin Cheon-hee's feet touched the ground, he grabbed the Black Heaven Blood Thread.
Crack!
But the creature's strength caused Jin Cheon-hee's body to be dragged forward.
"Ten Thousand Jin Hammer again!"
His body became heavy, and his feet planted firmly on the ground.
The next technique Jin Cheon-hee would use was only one.
Mountain-Splitting Strength!
That's right.
It was a secret technique from a colored book he had borrowed from the library.
It was a martial art left behind by a madman who had trained his external energy to the extreme.
For some reason, it had been placed in a colored book.
To learn it, he had to tear the book apart and reassemble the pages.
Jin Cheon-hee recalled the mantra of Mountain-Splitting Strength.
Following the mantra, he moved his muscles.
Using the Ten Thousand Jin Hammer to stabilize his weight, he pulled with the strength of Mountain-Splitting Strength.
The iron spear, embedded in the creature's throat, wouldn't come out.
The Ten-Thousand-Year Fire Carp resisted.
Sssshhh—!
Jin Cheon-hee didn't falter.
The divine artifact Yeha Ryun had gifted him, the Black Heaven Blood Thread, was pulled with tremendous force but didn't break.
As long as it didn't break, there was hope.
Jin Cheon-hee wrapped the Black Heaven Blood Thread around his shoulders and pulled, exhaling with each effort.
"Heave, ho!"
From here on, it was a battle of endurance.
If he could pull the creature even one centimeter onto land, Jin Cheon-hee would win.
He pulled and pulled, repeating the motion.
He continuously maintained the internal energy for the Ten Thousand Jin Hammer and circulated the external energy of Mountain-Splitting Strength.
How much time passed?
Jin Cheon-hee felt his entire body aching.
Purple bruises spread on his arms where the rope was wrapped.
He couldn't feel anything.
But the creature was also struggling.
Jin Cheon-hee circulated the Five Elements Divine Technique.
It wasn't a major circulation, just a single flow through his meridians, but it sent vitality through his body.
Relieving his fatigue, he pulled again.
"Heave, ho!"
This wasn't the magnificent battle between man and spiritual beast that Yeha Ryun had shown.
It was just a stubborn repetition.
Finally, the creature's snout began to appear above the water.
Splash—it began its final resistance.
At that moment, Jin Cheon-hee summoned the last of his strength.
"Pull!"