The Demon King Overrun by Heroes Novel - Chapter 112

Chapter 112
## Chapter 112: What Are You Doing?

A full week had elapsed since Hillun Kagil first tracked down Martin.

Much to their relief, the rest of the royal family had not yet interfered.

“Hillun Kagil has kept a low profile. While we can’t hide forever, as long as we are careful to maintain this silence, the truth should remain buried for the time being.”

“It’s a relief Hillun Kagil showed such discretion. See to it that the perimeter around everyone involved is fortified.”

“As you command, Your Highness.”

“And regarding Hamstrine? Has anything surfaced that mirrors Hillun Kagil’s claims?”

“It is difficult to say for certain if the situation qualifies as ‘unusual’.”

“Explain ‘difficult’.”

“As you are aware, Hamstrine is classified as a restricted territory.”

While not as desolate as the frozen wastes or the Erjest Mountains, the Hamstrine Gorge remained a domain ruled by predatory beasts. It was a region that fundamentally rejected human presence. To counter this, the Empire had historically established strongholds nearby to contain monster outbreaks—a practice that continued to this day. They maintained a constant vigil over the creatures inhabiting the gorge.

“The reports indicate no spikes in demonic energy of the sort Hillun Kagil described. However, over the last decade, the monster population has been in a steady state of decline. This is particularly true for the specimens typically driven to madness by demonic influence.”

“The corrupted monsters are vanishing?”

In the depths of Hamstrine Gorge, monsters occasionally succumbed to demonic energy, losing their sanity and turning into feral engines of destruction. Every time this happened, the Empire sent scouts, fearing the arrival of a new Demon King, though no towers were ever discovered. They had confirmed that traces of demonic energy lingered in specific pockets without fading away. The cause remained a mystery; most assumed it was a lingering residue from the convergence of the five Demon Kings and their respective towers. If a monster happened to absorb this stagnant energy, it went berserk.

“Indeed. A specialized team was sent to investigate further.”

“And what were their findings?”

“They report that the concentrations of demonic energy have plummeted.”

“That is impossible.”

Demonic energy was a force native to the demon realm, an alien dimension. As an external impurity, it was fundamentally incompatible with the natural world. It was believed that it could not dissipate on its own, and even through man-made intervention, it could never be fully erased. This was the firm stance of the Empire, which was why they had opted for containment rather than eradication. They feared that tampering with the remnants of fallen Demon Kings might trigger a greater catastrophe. Despite decades of study, the energy had never once shown signs of receding.

Until this moment.

It had dwindled?

According to every law of magic known to them, such a thing was a physical impossibility. Unless, of course, a living being was intentionally draining it.

“Is it possible…”

“Count Travian exerted every effort to find the source, but there were no signs of a Demon King’s presence.”

Count Travian was the warden of the gorge and the supreme commander of the Hamstrine territory.

“And the assessment of the heroes?”

“Yes. Several heroes were contracted to find the cause, but they were equally baffled. The prevailing theory now is that over a vast period, the demonic energy may have naturally transmuted into something resembling mana.”

“A possibility, perhaps.”

Under normal circumstances, the Third Prince would have dismissed the matter. But Hillun Kagil was a variable he could not ignore. If the hero was spinning a web of lies, the situation was simple—but why would he? Why go to such lengths to make contact?

“I must speak with Hillun Kagil again.”

Martin stood up from his desk.

—

“It has only been a week, Your Highness.”

“I realized I have been a poor host to my guest.”

“Think nothing of it. I imagine your schedule has been quite demanding.”

“I acted on your information and sent scouts. The intelligence suggests that Hamstrine is indeed undergoing a subtle transformation.”

“I see.”

“No one can explain it. The group I sent included elite knights, sorcerers, and even heroes. They all reached the same conclusion: the ancient energy is simply fading with time.”

“I understand their perspective, but demonic energy does not simply evaporate.”

“That has been our understanding. But could there be a phenomenon beyond our current knowledge?”

“If you truly believed that, you wouldn’t have come to see me.”

A thin smile played on Hillun’s lips. A heavy silence filled the room.

“Are you certain there is something hidden there?”

“I am.”

“The other heroes detected nothing. Some of them were ‘stars’ who possessed reputations as formidable as your own.”

“Your Highness, I cannot speak to why they failed where I succeeded, or what makes me different. I only know that after taking the lives of two Demon Kings, my senses have become… refined.”

“So, you are boasting after all.”

“You flatter me.”

Though it galled him, Martin had to accept the logic. Slaying even one Demon King resulted in a monumental surge in a hero’s power. That was the weight of a Demon King’s essence—so what of a man who had ended two? If Hillun alone perceived a threat that others missed, his word carried weight. In this era, Hillun Kagil stood alone as the only hero to have hunted multiple Demon Kings.

“What exactly did you sense?”

“A staggering amount of demonic energy.”

“Be more specific.”

“A person.”

“A human?”

“One who serves as a vessel for an immense volume of demonic power.”

Hillun’s gaze grew sharp.

“A human. A black mage.”

—

Black mages were historically defined as those who traded their souls to Demon Kings for forbidden power. In many worlds, they were the harbingers of doom, but in Aren, they were an afterthought. Since the Demon Kings here were relatively weak, there was little incentive to serve them. Over time, the practice of black magic had rotted away and vanished from the continent.

Normally, such a claim would be laughed off. But Martin did not ignore it. If Hillun phrased it this way, there had to be a significant threat behind it.

“Are you convinced this individual poses a genuine risk to the Empire?”

“Without a doubt.”

“I am a prince of the realm, and my decrees have consequences. To mobilize, I require tangible proof of your claims.”

“If it is evidence you require, I shall provide it.”

“What are your terms?”

“Promise me that once I bring you proof, you will provide the necessary backing for the campaign against the Flame Demon King.”

“If the situation permits, you shall have it.”

“My thanks.”

Just as they had arrived under a veil of secrecy, Berge and Hillun slipped out of the capital unnoticed.

“……”

On a secluded stretch of the imperial road, far from prying eyes, Hillun finally let out a long, weary breath.

“What are you doing?”

“Is this for real?”

“……?”

“Is there truly a black mage lurking in Hamstrine Gorge?”

“Watch your tongue. You think I would resort to petty fabrications?”

“I’ve staked my entire life on you, Demon King. I stood before the prince and made grand claims. I have no safety net left.”

“If I hadn’t stepped in, your skull would currently be a decoration on the Tower of Frost.”

“……”

Hillun had no rebuttal for that truth.

“Then tell me this much. It’s dangerous, isn’t it? Even if this person exists, how can one man truly threaten the entire Empire…”

“Not all who walk the path of black magic are equal, just as not all demonic energy is of the same caliber.”

“I realize this mage must be talented, but—”

“Talented is an understatement. Demonic energy is a sovereign power intended only for demons. To grasp that power through sheer individual merit and become a self-taught black mage…”

“It’s impressive, I suppose, but—”

“No, you are still missing the point. That energy isn’t some common byproduct from a minor demon or beast. It is the raw essence extracted from the towers—the very remains of the Demon Kings. Do you think it’s natural for a mere human to decipher and dominate that power on their own?”

“……!”

“He managed it. And he has been gestating in that gorge for a significant amount of time. Can you fathom the strength of the forces he has amassed?”

“No way, that’s…”

“It isn’t.”

Berge shook his head slowly.

“As tempting as that power is, I have no desire to claim it for myself. It’s a beautiful but lethal poison.”

If a tower were nearby, he might reconsider, but they were in the heart of the Empire. Thousands of soldiers guarded the gorge, and the distance to Erjest was far too great to bridge easily.

“Furthermore, delivering him to the Empire serves our current interests better.”

Providing the Third Prince with a catalyst to escalate the civil war and destabilize the imperial foundation was far more strategic.

“What is your plan?”

“What do you think? He is a black mage.”

“Yes.”

“And I am a Demon King.”

“…Wait, what?”

“When a Demon King encounters a black mage, there is a natural order of things.”

He intended to teach this arrogant scavenger a lesson and force him into submission.

“That is the fundamental hierarchy between a Demon King and a black mage.”

“You certainly embrace the role, don’t you?”

“I’ll take that as a compliment. By the way, what became of the others?”

“Which others?”

“The ones I freed alongside you, the ones I converted into black mages and knights. Aside from Aman, I haven’t tracked them.”

“I have no clue. Getting close to them would be a death sentence; if they made one mistake, the demonic energy in my own body would be exposed.”

“A wise choice. They are largely incompetent anyway. But are they even still breathing?”

“Shouldn’t you be the one to tell me, Demon King?”

The seals of obedience were etched into the souls of those black mages and knights. They were crafted so that the Demon King would feel the severance when a subordinate perished.

“The bond isn’t exactly unbreakable, is it? Perhaps it’s faded?”

“I can practically hear you plotting from here.”

“It was just a question.”

“Don’t get your hopes up. You aren’t leaving my service.”

“That wasn’t my implication.”

“I’m sure it wasn’t.”

He looked like a scavenger waiting for the perfect moment to strike. Berge snorted and pivoted back to the task at hand.

“Regardless, assume they are all still alive.”

No stray souls had returned to him yet.

“See? You knew the answer all along.”

“Is that yeti oil?”

“What?”

“You’ve spent a few months in the warmth of the north and grown soft. You’re using too much lip balm.”

“The cold was so bitter my tongue practically turned to ice.”

Hillun fell silent.

The pair turned south immediately. Following the Third Prince’s command to remain undetected, they bypassed the major teleportation hubs and instead carved a path through the desolate mountain trails.

“To think a human dares to give orders to a Demon King. I will settle this debt later.”

“Isn’t this ‘debt’ actually helping you lay siege to your own tower?”

“……”

“…Demon King?”

“…The more I think about it, the more it irritates me.”

Collaborating with a hero who intended to destroy him, being asked to facilitate that very destruction, and then fulfilling the enemy’s prerequisites? It was absurd.

‘Why am I doing this?’

Because it was the fastest way to bring the Empire to its knees. Ultimately, it was the path to dominating Aren and securing a life far better than the one he had lost before his regression. He had to tolerate this frustrating irony.

Though they traveled on foot, their status as a hero and a Demon King allowed them to cover vast distances in mere days.

“…The security here feels remarkably lax.”

Hamstrine Gorge. It was far more than a simple canyon; it was a sprawling territory the size of a minor kingdom, a veritable bastion for monsters. The Empire had ringed it with four massive fortresses. Normally, these walls should be buzzing with the tension of an impending siege…

But as Berge looked upon Alkan Fortress, that tension was nowhere to be found. There were sentries, hired blades, and a handful of heroes, but nothing more. There was none of the grit or desperation he had witnessed in the frozen north.

“I think we found our answer in the conversation with the Prince.”

“I have a theory as well.”

It was likely the work of the black mage nestled within the gorge. By siphoning off the demonic energy, the number of rampaging monsters decreased. By reanimating fallen beasts as undead, the threat level dropped even further. Over time, the defenders had simply grown complacent.

This worked in their favor. The lack of vigilance allowed Berge and Hillun to slip past the fortress and enter the gorge with ease.

Once they were deep within the territory, far from the eyes of any hunters or knights, Berge suppressed his mana and unleashed his demonic energy. His red hair and eyes shifted to a deep, abyssal black. He took a long, satisfied breath.

“Much better.”

The air was saturated with demonic energy. Power surged through him, mirroring the sensation of being inside a tower. While he wasn’t technically stronger due to the world’s interference, the abundance of ambient energy made his powers far easier to manifest.

He walked with measured steps, letting his presence ripple outward. The ancient, stagnant demonic energy of the gorge began to vibrate in response to the Demon King’s authority.

“I’ve found it.”

“So soon?”

“I am a Demon King, after all.”

The black mage had managed to hide from heroes for several reasons. His human nature allowed him to mask his energy perfectly until he chose to strike. Furthermore, heroes—who often relied on an instinctive revulsion to demons—found the entire gorge so repulsive that a single person was hard to pinpoint.

But Berge was different. He was of the race that commanded this energy. He was a lord of the towers. Finding the point of highest concentration was as simple as breathing.

“Are you truly going through with this?”

“Of course.”

“Do you think he will actually submit?”

“His opinion is irrelevant.”

Berge was the King; the other was merely a practitioner of his craft. Berge surged forward, and Hillun followed in his wake.

—

The heart of the gorge.

A jagged fissure in the rock face revealed a hidden tunnel. The path spiraled deep into the earth, growing dark and slick with moisture. At the very bottom, it opened into a cavernous void.

The sight was a vision of the underworld. Mountains of corpses were piled high, most reduced to yellowed, crumbling bone. Byrif sat atop one of these macabre thrones, his legs crossed casually. Water dripped rhythmically from the ceiling above.

Then, a sound.

*Clack-clack—*

A withered skeleton sprinted toward him from the tunnel entrance.

“What is it?”

*Clack-clack—*

“Intruders? Have the Empire’s hounds finally found this place?”

*Clack-clack—*

“A hero and a source of demonic energy?”

The skeleton nodded frantically.

Byrif frowned. Such a combination was unheard of. But his undead servants were incapable of deception.

‘Has the Empire employed a black mage to hunt me down?’

No, that made no sense. The Empire wasn’t even aware of his existence.

‘I’ll get my answers soon enough.’

Byrif stood up.

“How many are there?”

*Clack-clack—*

“Only two?”

Paltry numbers. And yet, they had the nerve to enter his sanctum. They must be exceptionally confident.

‘A Star-rank hero?’

It didn’t matter. In this place, he was invincible.

*Thud, thud—*

Heavy footfalls echoed from the darkness. Byrif descended from his throne of bone. Two figures emerged. One was a hero whose very presence made his skin crawl. The other was a man radiating a dense, overwhelming demonic energy—a fellow black mage.

‘Where did a black mage of this caliber come from?’

What fool had made a pact with a Demon King to gain such power? And why was he walking side-by-side with a hero?

“Identify yourselves,” Byrif commanded, his voice a low growl.

The footsteps stopped. Though the cavern was dark, Byrif’s eyes, long adjusted to the gloom, analyzed his visitors.

‘Dangerous.’

The hero was more repulsive than any he had ever encountered. The demonic energy in the air was churning. But it was the other man who truly unsettled him. He was clearly a practitioner of the dark arts, yet his depths were unreadable. Even with Byrif’s years of refining his senses, he could not see the bottom of the man’s power. A cold shiver ran down his spine.

“Speak.”

No response.

“Very well.”

Byrif channeled his power.

*Rumble—*

The mountains of bone and flesh began to shift and groan. They knitted together, forming hundreds—then thousands—of skeletal warriors. Every corner of the cavern was filled with his silent legion. Within moments, the two intruders were surrounded.

“If you won’t speak, I’ll tear the answers from you. Who sent you? How did you—”

“Quiet, whelp.”

The black-haired man spoke, cutting him off effortlessly. Their eyes met.

A primal terror seized Byrif. Every instinct in his body screamed at him to flee. Cold sweat drenched his back.

“You want to know who I am?”

The man moved with a lazy grace. He flicked his wrist.

An invisible weight of demonic energy slammed into Byrif, crushing the air from his lungs.

“Gah…!”

The energy inside Byrif’s own body began to rebel. It thrashed against his veins, trying to tear its way out.

“H-how is this…?”

He had lost all control. The sheer impossibility of it left him breathless.

“Who… what are you?”

The erupting energy shattered his domain, collapsing his bone towers like houses of cards. Byrif spat a mouthful of dark blood.

“Take a guess.”

The man tapped his fingers together, looking bored. He began to walk forward slowly.

“In the demon realm, I was known as Berge Dayas.”

One step forward. Byrif stumbled back. Black embers began to dance around the man’s feet.

“After I descended to this world, I became the Demon King of Erjest.”

Another step.

“And now, I am the Flame Demon King.”

One more step.

*Thud—*

Byrif’s back hit the cold stone wall. He was deathly pale, his entire body shaking uncontrollably.

“And as for now…”

The man’s lips curled into a faint, icy smile. His gaze pierced through Byrif’s soul.

“I am your new master.”

They were now standing face-to-face. The man looked down at him with eyes full of absolute authority. He reached out and placed a pale hand on top of Byrif’s head.

“What are you doing?” the man whispered.

“Kneel.”

*Thud—*

Byrif’s knees slammed into the stone floor, cracking the earth beneath him.