The Double Agent of the Heavenly Demon Sect

Do you know what happens when you spend more than half a day striking a scarecrow with a sword?

Blisters form on your hands.

“… Pfft.”

I wrapped my hands in bandages. Any kind of movement hurt, but such pain was nothing. Every step felt like my body was breaking. The agony was relentless, but what harm could a few blisters do in comparison?

I moved forward. My stances were clumsy, and my strikes weren’t smooth. Even striking thin air made a pitiful sound, accompanied by excruciating pain. Yet, for some reason, I found myself laughing.

I am improving. The first swing had been unbearably painful, but the next was just a bit more bearable. 

The faint sound of cleaving air, once as soft as a mosquito’s buzz, had grown to something like a gentle breeze. 

Each night was filled with the groans of pain, but I could feel myself getting better.

Taking one painful step after another.

I stepped back from the scarecrow I’d been hacking at with my sword, caught my breath, and closed my eyes.

The Endless Tribulation.

It still burrowed into my body, refusing to allow even a single wisp of energy to flow, offering only pain instead of strength.

But that was fine. The pain hadn’t dulled, but I could endure it. In fact, I felt grateful for this new life I had gained through bearing the tribulation.

In the past, I wielded a sword without seeing any progress.

And now?

Even if just by a sliver, I could see improvement. I could lift a bit more than yesterday. A life once filled only with despair now had a glimmer of opportunity.

A proper teacher. A clear path. An oppressive darkness pierced by a faint, distant light.

“… Pfft.”

It was a daily life I couldn’t help but laugh about.

I was genuinely grateful to the Heavenly Demon, to my fate.

… So much.

When was the last time I felt this sense of liberation?

‘Just keep piling it on. Eventually, I’ll reach it.’

Even if that meant achieving it in my old age, it didn’t matter. This was my first true desire, the first genuine ambition I had held.

‘I will become a martial artist like the Heavenly Demon.’

Even if it was an unattainable dream…

My struggle would remain etched in my soul.

“Jeokwoon.”

I turned toward the voice. A figure dressed in black had appeared without a sound and stared at me.

I’d never seen the face beneath the hood, but the cold tone when she called my name always gave me chills. She must despise me. Still, I willingly lowered my head before her. I’d endure anything to gain strength.

After all, I was already the Heavenly Demon’s dog.

As long as I could become more like her, I was prepared to keep up this charade.

“Yes.”

“I told you to stop using that sword, didn’t I?”

“My apologies.”

“… Tsk.”

The black-clad figure, the First Demon, stood before me.

“You’re not ready to hold a sword. Your body must be trained first to earn that right. A heavy wooden staff would snap if you placed it on a weed. Right now, you’re a weed. A sword is no different than a heavy staff you can’t handle.”

She tapped the scarecrow, and a red energy pulsed upward.

“You can’t use internal energy right now. The only thing you can train is external strength. This state of your body will persist until the tribulation fully settles. Until then, focus on building your foundation. Don’t even dream of using a sword until your pathetic body is at least passable. Otherwise, it’ll only poison you.”

“I understand.”

“You’re not listening at all. Stop staring at my fingertips, you pervert. Even if your restraint broke after a lifetime of holding back, does it make sense that you’d turn into a crazed training maniac? It’s a matter of nature. You’ve always been a madman, only repressed by your own rationality. But regardless of your nature, focus on my words when I speak. Don’t look at my techniques; focus on the end of my sentence. I don’t like repeating myself. If you do it again, I’ll snap your neck.”

“My apologies, First Demon. I will focus on your words.”

“… Why do I find you so irritating?”

The scarecrow’s neck broke with a crack. It happened in the blink of an eye, the moment the First Demon moved her hand.

“You can’t even imitate this. So, do you think I’m showing you this just to mock you—.”

“… Weren’t you trying to mock me?”

She kicked my shin, and the First Demon growled.

“Don’t get cocky just because you understand a little. We’ve only been here for two months, you idiot. Do you think you’re my disciple or something? If it weren’t for the command of the Cult Master, I’d have ground you up and thrown you to the dogs.”

“Do dogs eat dog meat? If I were them, I wouldn’t eat it…”

“…”

I couldn’t see her face under the hanging straight-line talisman, but I could feel her glare as if she wanted to chew me up. Still, I had no intention of changing my tone. She couldn’t kill me and had to teach me.

Besides…

I felt free. When was the last time I felt such liberation? In these moments, I could truly be myself.

The nature I had hidden to protect my family.

The rebelliousness from the days when I had to keep working without changing my expression.

Even as I made these jokes, I was enjoying myself. Just learning martial arts filled me with joy; how could anything seem like misfortune?

She was sharp but meticulous. She looked after me carefully despite her grumblings.

A good person.

Of course, that didn’t change the fact that she was dangerous.

“Jeokwoon. Focus on my words. If you lose focus again, I’ll break your bones. In a month, you’ll join the Blood Demon Squad. There are plenty of people there who can do things like this.”

“What exactly does the Blood Demon Squad do?”

“It’s the perfect place to toughen you up. Normally, they train, but when there’s work, they go out of the ‘Devil’s Valley’ to handle it. It’s no easy place. There’s barely enough food to eat, and you’ll have to struggle to survive.”

“And the spy work…?”

“We’ve found a replacement. They’ll take over your role. Or what? Are you still clinging to the Martial Alliance?”

Her sharp gaze cut through me. 

I shook my head.

I had no reason to lie. While I was part of the orthodox sect, I had no good memories to take with me. None at all.

This side was better.

This place, where they taught me things that nourished and strengthened me.

“I am the Cult Master’s dog.”

“At least you know your place, so I’ll let you live for now. Jeokwoon, focus on your training. When you join the Blood Demon Squad, you’ll operate in pairs. Any time a member is lost, a replacement joins immediately. The Blood Demon Squad always maintains a roster of thirty. And every month, more than ten die.”

“What do they die from?”

“They usually die on missions. The second most common cause…”

the First Demon kicked the fallen scarecrow’s neck.

“… Is being killed by their comrades, who despise incompetent allies. Right now, you’re not even third-rate. At the very least, reach the second tier so you can carry your weight. That’s the only way you’ll survive.”

———

The Nine Heavens Blood Demon Art was a martial art composed of nine forms.

Nine heavens. A demon art that pierces through them.

There was a reason why the First Demon called it a beastly martial art. This technique primarily focused on whittling down the opponent.

Rather than evading a blow, you’d throw yourself at your enemy if it meant you could take them down first.

To get the meat sliced in order to break a bone—it required a willingness to sacrifice flesh and bone, making it a highly dangerous technique for the user.

Just the first form alone required movements that ignored any regard for one’s back. A robust body was essential.

Even if you absorbed an attack, you had to withstand it with minimal injury.

Even if half your flesh was sliced away, the bones beneath could not afford to be shattered.

Pain. To master this martial art, one had to endure a bone-deep level of pain.

But ironically, even the sum of all this pain was weaker than the agony inflicted by the Endless Tribulation.

“… Haha!”

I could laugh freely as I walked through this hell. Pushing my body to the edge and consuming the food the First Demon brought, I focused on strengthening my body.

Every day felt like hell. But I could endure it.

Becoming accustomed to pain didn’t mean I started to enjoy it, but I could condition myself to like it. 

My skills improved continuously. The days when the First Demon would click her tongue at me became fewer.

I mastered the first form of the Nine Heavens Blood Demon Art: ‘Demon’s Ghost Hand’. It required painstaking effort to apply the techniques.

Apart from mealtimes, I was always training, kicking and striking through the air. 

I would wake up standing on my hands, sometimes sitting under a waterfall for hours to ease the blood rushing to my head. 

Every night, I meditated, observing the Endless Tribulation that had taken root in me. 

However, it remained dormant, making gathering or directing energy still impossible.

One month passed. 

Counting all the days here, it had been three months—a long time but, for me, far too short. 

When the First Demon would say my bones needed conditioning, she’d show up with a club, and then time seemed to stretch endlessly.

“This is the fastest way. Don’t worry; no scars will remain. You’re a tough one, so you should be able to handle it, right?”

I reconsidered my initial judgment that the First Demon was a ‘good person.’ She was insane.

My ruined body cycled between regeneration and destruction. In that process, I felt the Endless Tribulation gradually taking root. 

What would happen once it was fully entrenched?

Each morning, I started to feel slightly refreshed when I awoke. 

The severe pain had become so routine that I could now bear it without biting my tongue or tearing at my thigh. 

My senses weren’t dulled; instead, they had sharpened. 

Day by day, as the Endless Tribulation grew within me, I felt myself becoming stronger.

A second-tier martial artist.

On the last day, when I performed the Nine Heavens Blood Demon Art, I confirmed that I had surpassed the level I couldn’t reach even after years of effort.

“Just barely hit the mark.”

For the first time, the First Demon’s voice held a note of kindness.

“The effect of the Endless Tribulation, I presume. Good. Your body stabilized faster than expected. But don’t get complacent. If you plan to walk a long path, the Nine Heavens Blood Demon Art will become a hindrance. The early stages are fast, but progress slows as you advance. Demonic arts are characterized by an easy entry but extreme difficulty at their peak. If you don’t reach the proper level in time, the demonic nature of the art will consume you.”

“Are you concerned about me?”

“Shut your mouth. Instead of running your mouth, you should be struggling for your life. I don’t want to bury the dog I’ve worked hard to train.”

the First Demon took me to a place called Devil’s Valley. Looking down at the abyss below the cliff, I turned to look at her one last time.

“Am I a member of the Blood Demon Squad now?”

“If you survive.”

“Is this the kind of work the Cult Master’s dog does?”

“The Blood Demon Squad, the Cult Master’s dog? Tsk. If you insist on a comparison, it’s more like an ant. Placing you here is to train you before you become a dog. The Blood Demon Squad is one of the lowest divisions within the cult and can be replaced anytime. I trained them myself, but they’re ultimately a disposable unit.”

The First Demon nodded toward the cliff.

“From now on, you’re Number Thirty. Forget the name Jeokwoon for now. Remember, you’ll leave this place as the Cult Master’s dog when she summons you, but if she never calls, you’ll remain with the Blood Demon Squad for life.”

“… Understood.”

I gazed down into the abyss, its depths invisible. I took a steady breath and turned back to the First Demon.

“First Demon.”

“What?”

“May I know your name?”

“What’s your intent?”

“Since coming here, you’re the first person I’ve truly formed a connection with.”

The Eight Demons of the Heavenly Demon Cult. Despite their fame, not all of their names were known. They were usually referred to by numbers, and only a select few within the sect knew their true names. That’s why I wanted to hear it.

“I wish to know as Jeokwoon, not as Thirty.”

The First Demon scoffed and lightly placed her foot on my back.

“The First Demon is the First Demon. There’s no other name. I am the Heavenly Demon’s sword. I am not your teacher, nor your acquaintance, and certainly not your lover in any special relationship.”

Her tone was as sharp as ever, yet there was a slight softness at the end.

“But when the day comes that you truly become the Cult Master’s dog, as the overseer, I won’t refuse to tell you.”

“I will do my best.”

“Now get lost. Whatever you do down there, don’t expect any help from me. Drop any useless expectations and just disappear already.”

With a push, the First Demon’s foot left my back. I staggered forward, stepping into Devil’s Valley.

An endless stone staircase stretched before me. As I descended, I pulled down the black hood that the First Demon had given me over my head. 

It was like hers, with a talisman hanging in front. It appeared to obscure my vision but, strangely, allowed me to see ahead clearly.

So, this is the famed ‘sorcery’ of the Heavenly Demon Sect?

The hood felt a bit stifling at first, but I quickly grew accustomed to it. My eyes adjusted to the slightly darkened view.

Finally, my feet touched solid ground. 

After more than an hour of descending, a lone torch flickered at the end.

“Number Thirty.”

The voice was quiet, and the figure was not particularly large. It was a woman’s voice, but I couldn’t discern anything beyond that.

Beneath the torch, she wore the same black hood as I did. 

At a glance, she looked small and delicate, yet…

“Follow me.”

… All I could sense was an overwhelming, eerie strength.

With the First Demon, I couldn’t even gauge her strength, and the same was true of this woman. 

She exuded a tranquility that was imperceptible without reaching a certain level. To me, she was both a blade and yet something beyond a blade.

A guy with a second-rate level of skill couldn’t even begin to measure her presence.

I quietly followed behind her.

Beyond the torchlight, the landscape of Devil’s Valley stretched out. It was a stifling space filled with cliffs and rock crevices, and covered in an eerie, almost odd nature. 

Each plant and creature was unfamiliar, something I had never seen before.