The Demon King Overrun by Heroes

Chapter 8: 100-Year Contract

Even if things had somewhat stabilised, Hortonwork was still the front line facing the prohibition zone. Monsters poured in almost daily, and battles broke out constantly.

Naturally, the slaves gathered in Hortonwork were rough and highly efficient in combat.

Maybe that was why. The elf was a bit muscular. No—extremely muscular.

“How may I help you?”

A merchant who had been scribbling on documents at a desk set to one side of the communal space noticed us and approached.

He exchanged a few words with the guide, then rubbed his palms together with a smile.

“Ha ha, I hear you’re looking for a good slave. You’ve come to the right place. Would you like to have a look around first?”

“No need.”

Berje walked straight over to the iron cage where the elf was imprisoned. Seeing him up close pleased him even more.

“Ah, an elf—so you’re interested in elves!”

The merchant let out a greedy laugh.

Elves were expensive. Ever since the war with the other races ended and non-human slaves were officially banned, their price had risen even more.

“Thorough, aren’t you.”

“Ah, elves are so capable that ordinary restraints are useless. They break them and run. This much is basic.”

“I like his eyes.”

My gaze stayed fixed on the elf.

His once-brilliant green hair was matted and filthy from long neglect. Even so, I liked the deep green pupils that glared like a furious beast. Even with his limbs bound by chains, he hadn’t lost his fighting spirit.

The simmering hatred toward humans made me like him even more.

Only the bit gag in his mouth was a flaw—I wanted him to speak.

“I want to talk to him.”

“He’s a rough one. If I remove the gag, something might happen…”

“And if I say it’s fine?”

“Well, but…”

“Even if the elf dies or causes trouble, I’ll take full responsibility and purchase him.”

“Well, if you insist…”

“How much?”

“As you know, elves are a little pricey. Four gold coins—no, five.”

I took out the gold and flicked it lightly with my fingers. The merchant’s face lit up as he accepted the glittering coins and opened the cage door.

“Enjoy your conversation!”

“You leave too.”

“I’ll wait outside.”

Bark and the merchant disappeared. Berje stepped inside the cage and stirred up demonic energy.

“U-ugh…!”

The elf’s pupils widened. Even if his mana was restricted by the restraints, elves were among the most sensitive to energy among the demi-races—of course he could sense demonic energy.

I removed the gag. The elf’s mouth hung open, unable to close.

“You can’t bite your tongue. You can’t move either. So give up and listen quietly.”

He had no choice.

“I just paid a proper price and purchased you. Therefore, you’re my slave.”

Bloodshot veins surfaced in his eyes. His trembling mouth looked ready to spew a torrent of curses—

—but he couldn’t.

“I imagine your hatred is immense, having become a slave at the hands of humans and suffering through countless humiliations.”

“I’ll give you a chance.”

“Will you die here in this cold iron cage as a slave?”

“Or will you take my hand and seek revenge? I’ll help you tear apart the bastards who made you like this and bring humans to ruin.”

“Well?”

There was no answer. But his trembling pupils betrayed his turmoil.

“If you won’t bite your tongue, I’ll release the spell. If you agree, nod.”

The elf nodded. When I withdrew the demonic energy, he gasped for breath.

“Demon race—why would the demon race come to me?”

“You only need to answer.”

“Deals with demons always come with a terrible price.”

“I’m different. All you have to do is work for me. Fifty years. Be my loyal subordinate for just fifty years, and after that, I’ll give you your freedom. How about it?”

For an elf, fifty years wasn’t that long—so it wasn’t a bad offer, in my opinion.

“You expect me to believe the words of demons, who lie as easily as eating?”

“You don’t seem to object to the proposal itself.”

“It’s been five years since humans captured me and made me a slave. There were more than a few times when I wished I could just die from the humiliation.”

The malice he had stewed over for years had piled up and hardened into something irreversible.

“If I can tear apart with my own hands the ones who made me like this, why wouldn’t I sell my soul even to a demon.”

The elf growled in fury. The murderous intent oozing from him was so sharp it made my skin prickle.

“But you can’t trust me because I’m demon race?”

“There’s a saying among elves. Better to befriend a dwarf than trust a demon.”

“We also have a saying. Among the races of the Middle Realm, humans are the hardest to trust, but the most pigheaded are the elves.”

Elves were known to hate the demon race more than any other species. To some extent that was true—but it wasn’t out of some sacred duty to protect the world.

It was because the World Tree they worshipped upheld the world. And the demon race sought to destroy the world that the World Tree supported.

“As long as you work under me, I won’t touch the World Tree.”

“I must have said I can’t trust a word you say. Why would a demon even reach out to an elf in the first place?”

A painful point.

“I swear upon The Demon King’s Standard and the great First Demon Emperor. I will never break what I’ve said.”

“……!”

The Demon King’s Standard and the Demon Emperor were like life itself to all demons. It was simple faith, but because demons were ignorant, they guarded it as though it were their very life.

It ran so deep that even Arein’s creations knew of the demons’ devotion to the Standard and the Demon Emperor.

“In return, you will serve me faithfully. Swear upon the World Tree.”

This was why Berje intended to make an elf—not a human—the crucial core component.

Unlike humans, for whom there was no reliable means of compulsion or trust, elves had a clear one.

Their parent tree—the oath of the World Tree.

It wasn’t merely an act of faith. It was a direct binding tied to mana.

One who broke the oath would have the forest’s blessing stripped away by the World Tree.

And for an elf, losing the forest’s blessing was a pain worse than death.

That was why it could be trusted.

“Well?”

“…As expected of the demon race.”

The elf muttered.

“You make an offer I cannot refuse.”

Berje held out his hand. The elf clasped it.

“Your name.”

“I am Granada of the Maple Tree Tribe. I will make my oath before the Demon King who sent you, face-to-face.”

“In that case, you can do it right now. Because I am that Demon King.”

“……?”

* * *

The merchant cheerfully pocketed the gold coins. Beside him, the guide and Bark swallowed dryly.

‘Khuhuhu, what a perfect sucker.’

Since elf slaves were officially banned, their rarity skyrocketed. Naturally, elves were expensive.

But the price varied wildly. Females were more expensive than males, and younger elves more than older ones.

But that elf’s issue wasn’t any of that.

A stubborn beast. Even after five years, he hadn’t lost his fighting spirit and continued to curse humans. No one wanted an elf like that. He even tried to bite his tongue and kill himself so often they had to keep a gag on him.

If only he had been a pretty woman, someone might have bought him for other purposes even with those issues. But that was impossible. He had absolutely no value as a product; they simply hadn’t killed him because it would have been a waste of money.

And yet someone actually bought that for five gold coins. He never imagined the angry price he threw out would be accepted as-is.

“Bark, you said he’s the one you brought?”

“Yes.”

“Is he some successful merchant? Or part of a major mercenary company?”

As far as the merchant could imagine, there were only two reasons someone would come all the way to Hortonwork to buy an elf.

Either they were searching for an elf that matched the taste of some rich patron, or they planned to use him as combat personnel.

"I also received a request. I can’t tell you the client’s identity."

"Hey, it’s not like we’ve only known each other for a day or two. No need to be so stiff, is there?"

"...."

"Tsk, well, fine. Anyway, I sold off that troublesome thing. But unfortunately, he probably won’t get that elf. The moment the gag is removed, he’ll likely bite his tongue."

"You did it even though you knew that?"

"The one over there said it didn’t matter. I took the down payment."

The merchant casually shrugged. He felt refreshed. The elf who had tormented him was dead, and he had made money.

"If he ever needs another slave later, be sure to contact me. Then I’ll make sure he’s well taken care o...."

Just then, the closed door opened. The sucker slowly walked out. The merchant rubbed his palms together and approached.

"You’re out? Did the conversation go we...ll...?"

His gaze moved behind the sucker. There he was. The elf who should have bitten his tongue and collapsed on the cold iron-barred floor was calmly following him.

"Lower your eyes. You pig-like bastard. Before I tear you to death right now."

Judging from the growling, his temper wasn’t dead at all.

"Well, you’ve finished nicely. I’ll stamp the seal for you."

The merchant continued the conversation as normally as possible using superhuman mental control.

"No need."

"Huh? But without the slave seal...."

There would be trouble.

The slave seal wasn’t just a mark of enslavement but a magic circle that prevented the bearer from harming the caster. It was designed so that chanting the spell would inflict pain.

"If there’s a problem, I’ll handle it."

"Yes, understood."

"Let’s go."

"Yes!"

Bark hurried after him. When they came up to the surface, everyone’s attention focused on them. They were shocked that the elf had been sold to someone.

‘How did he tame that elf?’

Bark knew about the elf as well, since when the elf previously tried to escape and rampaged, he had been hired and had subdued him together with other mercenaries.

A creature so ferocious it couldn’t be tamed—nothing more than an impossible dream. He was extremely famous among the slave merchants.

They said he would never be sold and that the only way he’d leave the cage was by dying....

"Your mission ends here."

"Ah, yes."

Berje lightly snapped his fingers. A silver coin landed naturally on Bark’s hand.

"I liked you more than I expected, so here’s a tip."

"Thank you!"

"How long are you planning to stay in this city?"

"I plan to stay unless something big happens."

"Good. I’ll come find you later."

"Yes, anytime, please look for me—Bark—or the Red Falcon Mercenary Corps at the Mercenary Guild!"

Bark sincerely hoped that generous client would return to him again.

* * *

The first thing the Demon King did was buy him a meal.

The elf, who had been barely surviving on the minimum amount of food, finally ate his fill and contentedly patted his stomach.

"Is the Tower really at the top of the Ergest Mountains?"

"You’re very suspicious."

"Consider it fortunate that my fist didn’t fly when you called yourself the Demon King."

To the elf, the Demon King personally coming to a slave market to purchase a slave was impossible.

And yet he accepted it and came along because the other seemed confident he could prove it by showing the Tower.

By putting The Demon King’s Standard on the line, no less.

"You keep your promise too. If I’m truly the Demon King, you’re mortgaging not fifty years but twice that."

"An elf never goes back on his word. Unlike demons."

‘This is getting irritating.’

He kept snapping back—clearly he had guts. Should he just beat him a few times to start?

The Demon King considered it for a moment but then shook his head. Once they arrived at the Tower, the elf would grow a thousand tails. Holding back until then was its own kind of pleasure.

Meanwhile, the elf found the demon before him rather strange.

‘A demon thinking of using another race...?’

Demons usually trusted no one but their own kind. Naturally so. They were invaders, and every race in Arein was being invaded. Enemies who couldn’t coexist—trust was impossible.

"But this isn’t the direction of the mountain...."

The Demon King, who introduced himself as Berje, the one who would be his master for the next fifty years, wasn’t heading toward the Ergest Mountains.

"The market. The Tower doesn’t have any food."

"...?"

‘...Did he just say the market?’

It was instinct. A strange chill ran down his spine.

He called himself the Demon King. Even if that was a lie, he was undeniably a demon.

And Granada, who had lived over a hundred years as an elf, had never heard of a demon going grocery shopping. Demons who locked themselves in their Towers had no reason to visit a human market.

"...Are you really the Demon King?"

"You’re far too suspicious."

"Of course I am!"

Despite his suspicious gaze, the Demon King bought more than ten bundles of ingredients.

Only after stuffing all of them into his subspace did he smile in satisfaction.

"Now, let’s go.’”

They secretly leapt over the castle wall, avoiding the eyes of the guards.

"Ergest Mountain is overflowing with monsters. How are we supposed to climb that?’”

He voiced the question he had been holding in.

"In a Demon King–like way.’”

The answer was concise. And the meaning became clear soon enough.

‘The monsters aren’t attacking.’

Even when they saw them, the monsters didn’t charge—if anything, they avoided them. What could that possibly mean?

‘Could the entire mountain already be the Demon King’s territory?’

He swallowed dryly. Maybe he really was the Demon King. No—this went beyond that. The number of monsters in Ergest Mountain was unimaginable. If all of that was in the Demon King’s hands…

‘A catastrophic disaster.’

He might be the strongest Demon King ever to descend upon Arein.

"Well, we’ve arrived. This is my Tower.’”

Even when they reached the tower hidden deep in a difficult-to-find basin, and even when the tower was only five stories tall, the elf still thought so. The shock that the entire mountain was his territory had not faded.

But when he opened the door to the first floor,

passed the second,

and climbed to the third—

"…My god.’”

He was horrified in an entirely different way. He now understood why the Demon King had personally gone to the human slave market to buy him, and why he had bought ingredients.

"There’s nothing here?’”

The famed Demon King’s Tower truly had nothing.

"I prefer simplicity. They call it the beauty of emptiness.’”

"If you stay 'simple' twice, the tower itself might disappear.’”

"Still, isn’t it enough that I now have a slave who’ll serve me faithfully for a hundred years?’”

The elf shuddered at the lecherous smile. The Demon King had already proven himself. The fact that the empty tower had accepted its master was proof.

Now it was his turn to keep his promise.

But—

"Fraud! This is fraud!’”

He couldn’t accept it.

A Demon King’s Tower had a generally expected structure.

On the first floor, weak monsters and traps. Go up a bit—strong monsters. A bit more—demons welcome you. And at the top, the Demon King sits solemnly on a golden throne and greets the hero.

And in the end, you rescue a prince or princess imprisoned in the tower.

Depending on the tower and the Demon King, details might vary, but the overall structure didn’t change.

That was what Granada wanted. Even though now reduced to being a slave, he had been quite successful among elves. He never thought he would become an officer of the Demon King’s army and take revenge on humans.

Not a shattered future with no one and nothing.

At that moment—

Kwaang!

A thick hand clamped around Granada’s neck.

"Kuh...!’”

His face reddened under the overwhelming strength. His breath choked off as he struggled.

He drew up his mana.

"I’ve reached the end of my patience.’”

But the sharp demonic energy piercing through him snapped his mana in an instant.

A chilling killing intent. The elf felt with his entire body that the being before him was the Demon King.

"Keep your promise, elf.’”

"Th-that’s fraud! I’ve never heard of a Tower like this!’”

"I never said it wasn’t.’”

"I knew I shouldn’t have trusted a demon’s words!’”

"Regret is always too late, no matter how early it comes.’”

Yes, it was too late. Granada had already stepped completely into the Demon King’s territory and couldn’t escape alone. Between death and a hundred-year slave contract, the better choice was obvious. And maybe he really would succeed in his revenge.

The shock of the tower was intense, but the awe he felt climbing the snowy mountain was equally vivid.

"…I will serve you.’”

He swore by the name of the great World Tree. The mana of his heart formed a binding. If he broke his vow, the binding would shatter, and all blessings granted to him would disappear.

"Good.’”

The Demon King smiled, satisfied. Then he tossed one of the ingredient bundles he had bought in the village.

"Now then, go make some food first.’”

"...?’”

The elf failed to grasp the situation for a moment. And then he grew furious.

"I am a noble elf! I was quite accomplished even among the Elven...!’”

"But right now, you’re just an insolent slave.’”

"Don’t tell me you bought me just to make me cook?’”

"Not exactly.’”

The Demon King rested his chin on his hand.

"For now, I’d like you to shut up and just do it.’”

It wasn’t because the elf had annoyed him with constant snide comments while climbing the mountain.

It was simply that no creature in the tower could prepare anything resembling real food.

Or so the Demon King thought.