Chapter 110

Chapter 110: The Demon King's Castle (5)

GOOOOO—

Inside the Demon King's Castle—a place where the air was already murderous by default—the tension had reached new heights.

Not just the Heroes who'd followed me in, but even the Dullahans who'd served the Demon King for ages were trembling in their armor.

The reason was simple: the castle's master was displeased. Very.

The Demon King was furious.

"You dare... you would take my daughter?"

He must have mentally torn me apart a thousand times over. A demon king with a brutal temperament and overwhelming power acting on it wouldn't have been strange.

But in reality, he only seethed in silence.

Because Persia was standing right beside me.

A slave to his daughter's wishes, the Demon King couldn't bring himself to kill someone Persia had approved.

The Demon King began his desperate appeal.

"The Demon King's Castle houses warriors beyond comparison with these frail humans. Persia, shall I assign the captain of the guard to your training? Or this father himself could teach you."

"Being strong doesn't make someone a good teacher."

The Demon King's glare could have killed, but it didn't matter.

Killing intent was a cheap trick that fed on the fear of death. As long as I was certain I wouldn't die, no amount of pressure—even from the strongest being—could faze me.

What would actually kill me was Persia changing her mind.

So I kept talking.

"I understand a parent's desire to keep their child close. However, if your judgment costs your daughter her future, will you accept that? Will you ruin her future with your mistake, Your Majesty?"

"......!"

KRRRUMBLE—

The castle shook.

The Demon King's fury had intensified to the point where even the Dullahans were quaking like aspen leaves.

The Heroes' eyes screamed 'please stop' at me.

But this was the Demon King's limit.

He didn't touch me further. Not with Persia watching.

Persia drove the final nail with a firm voice.

"Father, please give your permission."

"Persia......"

"Ever since I was small, my entire world has been that tiny room at the top of the castle. My body is so frail it can't endure the demon realm's air without the Moonlight of Manifestation. How long can I survive like this? And what subject would ever wish to serve such a person as their ruler?"

"Persia......"

"I will follow this man. It's not just about my body. I want to broaden my world. To see much, hear much, meet many people, and build my horizons."

"Is that... is that truly how you feel?"

"Yes."

"My daughter... you've grown so much."

The Demon King pressed one hand to his forehead and bowed his head.

A voice on the verge of tears carried genuine emotion.

The killing intent that had saturated the castle vanished completely—dissolved by Persia.

The Demon King declared with the gravity of an epoch-making decree.

"So be it! Go! All this time, I have been raising a dragon's hatchling in a lizard's cage!"

We'd done it.

Persia and I discreetly clenched our fists.

In front of her father, Persia played the introverted girl—but her true nature was textbook demon tribe. Extroverted, mischievous, a typical demon through and through.

She'd never said it aloud, but deep down, Persia had grown sick of life in the Demon King's Castle.

The acting, the bedridden existence due to her frail body—all of it had been insufferably dull.

A chance to leave.

Perhaps more than healing, Persia simply wanted out.

"I look forward to working with you."

The impish grin she flashed me was practically a little devil's smile.

***

People commonly assumed that everything inside a Gate was part of the dungeon.

Strictly speaking, that was a misconception.

A dungeon was merely a monster's habitat.

Did monsters spend their entire lives inside those narrow dimensions called dungeons, with zero contact with the outside?

No.

The area beyond the dungeon existed.

However, when a Gate opened, the Evil Gods' influence severed the dungeon interior from the external space, making passage impossible.

But there was a way to reach the outside.

Hidden secret passages.

Paths that circumvented the barrier encasing the dungeon, allowing exit.

"Ugh, my body feels heavy."

"Probably not your imagination. The gravity seems stronger than Earth's."

"Good lord. Being in another world just became real."

My Hero party used the secret passage to emerge from the Demon King's Castle into the Demon Realm.

Our destination: the peaks surrounding the castle.

We needed to gather rare materials available only in the Demon Realm.

Before I could help Persia grow stronger, there was a preparatory step.

Mana sealing.

In Persia's current state—unable to walk properly—proper training was out of the question.

So the plan was to temporarily seal her mana, buying time for training.

Sealing mana deep within the body was far more difficult than simply removing it.

That was why we'd ventured into the Demon Realm—to collect materials for the sealing formula.

The Demon King's help would have been convenient, but dungeon-native entities couldn't use the passage, so that was off the table.

This was why I'd brought the S-rank Heroes.

"You see the four peaks around the Demon King's Castle? Collect materials from those peaks and bring them back."

"Yes sir!"

Sending S-rank Heroes on an errand like this seemed absurd, but considering the Demon Realm's dangers, it was necessary.

Compared to the castle's interior this was a cakewalk, but the Demon Realm itself was as hostile as an SS-rank dungeon.

A-rank Heroes couldn't handle even passing fodder here.

After dispatching the Heroes to each peak, I headed to the last one.

Beyond the sealing materials, there was another task now that I was in the Demon Realm.

"Jeivult."

【Heh heh, finally my turn? Master, should I be gentle?】

The black Magic Sword that had always hung at my waist.

By now, its nonsense had become so routine I'd developed immunity—in one ear, out the other.

I took Jeivult and sought out a cave hidden on the last peak.

This was the Demon Realm—Jeivult's birthplace.

Inside the cave, traces of collapse from the ancient Demon Realm War were visible. This had been the forge where Jeivult was created.

Meaning it was the ideal place to reforge it.

My blacksmith skill's proficiency was low, so this was the only place I could work on Jeivult.

The entrance had caved in, but fortunately the interior was largely intact.

The tools inside had been long abandoned but still looked usable.

"Let's see. Repair, upgrade, and for a bonus option—silence. That should do it."

How Jeivult had ended up on Earth was anyone's guess, but as a weapon forged for the Demon Realm War, it had considerable history.

No matter how well-crafted a weapon was, prolonged neglect degraded its durability and diminished its true power.

Repair alone would yield a meaningful boost.

Next, the upgrade.

Ego Swords possessed a special property.

An Ego Sword accumulated experience from every battle it fought.

For a Magic Sword, the amount of blood that had flowed through the blade determined its growth.

However, the accumulated experience didn't passively strengthen the weapon—it required a blacksmith's hand to properly absorb through reforging.

My previous owners, including Jo Seongung, were no pushovers—they'd have amassed considerable experience.

Absorbing all of that would significantly boost the weapon's power.

【Hm? W-wait, Master. That last one looks suspicious?】

"Just your imagination."

【H-huh? No... hold on!】

And finally, the most important addition: silence.

Exactly what it sounded like—a function that let me shut the Ego Sword up whenever I wanted.

Jeivult begged and wept, pleading me not to do it, but that was never going to work.

For the sake of my mental well-being, I commenced the enchantment immediately.

【N-NOOOOOO!】

Jeivult. Cut!

From this day forward, Jeivult was no longer a chatty Ego Sword—but a strong, stoic Ego Sword that only spoke when necessary.

Wasn't this so much cooler?

After completing all the reforging, I activated the silence function. A beautifully quiet Ego Sword was born.

I descended the mountain in the most satisfying mood imaginable.

***

Back at the Demon King's Castle.

An amber brimming with demonic energy, tears of a mermaid slumbering at the bottom of a deep lake, a vampire's jewel shimmering blood-red, and more.

The catalysts collected from across the Demon Realm were excellent for supporting magic.

"Once the sealing is done, your body might feel strange for a while. The loss of strength will be severe, so brace yourself."

"Okaaay!"

Persia answered with a vibrato-laced sing-song, practically bouncing with energy. Her excitement was obvious from her voice alone.

As I placed the materials one by one onto the freshly drawn Magic Circle, lights of various colors were absorbed into the formation. The key was carefully adjusting the ratio of each mana type.

One. Two.

Mana fell in droplets, like dew forming.

A single miscalculation could trigger a rampage of Persia's powerful mana.

That would endanger not just Persia but me too. And even if we survived, the Demon King wouldn't let it slide.

I completed the Magic Circle with utmost precision, and a vivid pink glow rose from the formation.

Success.

After some fine-tuning, I miniaturized the circle and placed it on Persia's abdomen.

The Magic Circle began sinking into her body.

"Ngh......!"

Persia's small groan immediately twisted the Demon King's expression.

Fortunately, there was nothing further to upset him. The sealing magic concluded successfully.

A moment later, Persia spoke in a languid voice.

"It feels... strange. Like this body isn't mine... empty."

"That's expected. We just sealed that enormous mana."

The seal was complete, but it was only a stopgap.

It would hold while Persia built her body—but if she strongly willed it broken or enough time passed, it would shatter instantly.

The Demon King checked Persia's condition multiple times before finally deciding to let us go and reseal the Gate.

"Human, if anything happens to Persia, your world will not escape ruin."

"I'll remember that."

"My beloved daughter, come here."

The Demon King spread his arms wide and called Persia, who walked into his embrace.

The Demon King then proceeded to deliver roughly fifteen minutes of assorted nagging before finally releasing her.

"You must come back safely. You must."

"Don't worry, Father. I'll return as a splendid demon."

"I'll hold you to that."

Watching Persia bow graciously and offer individual farewells to the lined-up vassals, the Heroes were moved.

"What a kind-hearted princess."

"Heh, if our country had a princess like her, I'd pledge my loyalty for life."

The Heroes spouted things they'd never say if they'd paid any attention to the vassals.

Look at those Dullahans. They couldn't even make eye contact with Persia and were radiating discomfort.

And then Persia—from an angle invisible to the Demon King—stamped hard on one's foot. Where'd the kind-hearted princess go?

Eventually, Persia even pretended to cry, saying she couldn't bear to part with everyone.

The Demon King wept too, and the Heroes' eyes reddened at the touching father-daughter farewell.

Farewells complete, Persia walked out with us.

Only then did she shed the mask of the grieving daughter and break into a radiant grin.

"This feels amazing. I love it! I'm finally outside that miserable castle—this isn't a dream, is it?"

"It's not."

"Good, good. Humans, introduce yourselves. I am the next Demon King you shall henceforth serve."

Her attitude flipped so fast that the Heroes stared at Persia with blank faces.

Undeterred, Persia kept monologuing.

"Lowly humans, teach me well and I shall grant you the whole world. Do your best."

Excitement aside, I had to throw some cold water on Persia.

"These people are done here. They're all going back where they belong."

"Huh? Then where am I going?"

The answer was obvious.

If getting stronger was the goal, you went to a place of learning.

"The Academy."