Chapter 37: The Demon King

The Demon King was neither a fanged beast nor a horned fiend,

nothing like the monsters humans had imagined for generations.

He was simply a man with calm features—

smooth black hair falling lightly over his shoulders,

and deep-set eyes like unreadable books.

There was nothing about his appearance that suggested power.

His clothing was plain, his posture upright, his voice low—

more like casual conversation than command,

its weight only felt after it was already too late.

Yet anyone who dared to linger too long in his gaze

felt as though they were coming apart from the inside.

His strength did not lie in his body,

but in a cold logic that acknowledged no emotion,

and in that faint smile that concealed more than it revealed—

a hidden promise… or a postponed threat.

He trusted no one.

Even his ministers and generals were nothing more than pieces

on an enormous chessboard,

moved at will and sacrificed without hesitation.

He possessed a rare talent:

the art of contracts and seals.

With a single word from him, an entire life could be bound by a condition,

or end beneath an eternal shackle—

etched, irreversible, and unforgiving.

His enemies said of him:

“He is a mind that stands ten steps ahead of the battle.”

His followers said:

“He does not care whether we live or die…

as long as the contract is carved into our souls

before it ever reaches our bodies.”

And though he had not raised a sword in decades,

no kingdom dared invade his realm.

For his mere presence

was enough to remind the world that power does not reside in muscle,

nor in magic—

but in a man who makes his enemies wonder:

Are they the ones attacking him…

or are they moving—precisely—

as he planned from the very beginning?

In the heart of the Demon Kingdom,

the man stood in absolute calm.

“I am Lucarion… the Demon King.”

A heavy silence settled over the place before he continued, his voice steady—

carrying no direct threat, yet needing none:

“I have three questions for you.”

He lifted his gaze slightly, his eyes never leaving Y.

“First… why did you enter my kingdom?

Second… why are a human and a vampire fighting as one team?

And third… why are you rescuing a demoness?”

Suddenly, a whisper echoed inside Y’s mind:

Don’t answer… this is a trap.

Y’s eyes shifted slowly toward the woman he was carrying.

He understood immediately—

it was her voice.

He looked back at Lucarion

and stared at him in silence, not uttering a single word.

Lucarion took one step forward.

“I want a logical answer… one that satisfies me.”

Then he said, in perfect composure:

“Domain… the Eternal Court.”

In the very next moment, the surroundings began to change.

The ground stretched unnaturally,

the air grew heavy,

and even the void itself seemed to submit to an unseen judgment.

At that instant, L stepped forward.

Without hesitation,

she activated her own domain.

“The Throne of Lunar Blood.”

The space split into two opposing halves—

an invisible boundary dividing two authorities.

Tension surged instantly.

The clash of energies alone was enough

to make breaths choke in the chest.

Lucarion observed the scene,

a faint smile forming on his lips.

“A domain… equal in scale to my own.”

Then he spoke calmly, without mockery:

“You are not bad, vampire.”

He paused briefly before continuing:

“But know this—

two domains existing at the same time

are nothing more than decoration…

until one of them collapses.”

At last, Y spoke.

“Thank you for the explanation.”

Then he added honestly,

as if thinking out loud:

“I was genuinely wondering…

what would happen if two domains were activated at the same time.”

He turned his head slightly toward L.

“Your domain is truly impressive… L.”

L gave a short, precisely measured royal bow and replied calmly:

“Thank you for the compliment.”

Y raised his gaze once suggesting toward the Demon King.

“If your name is Lucarion… remind me—

what were your questions again?”

An enraged voice erupted from the ranks of demons:

“You stand in the presence of the Demon King! Watch your words!”

Several demons stepped forward,

but before the tension could fully ignite—

Lucarion calmly glanced at the shouting demon.

“I believe I told you to be silent… Jalan.”

Jalan froze in place.

His body trembled,

then he immediately stepped back,

as if fear itself had drained the air from his lungs.

Lucarion turned his gaze back to Y and L,

observing them from above, thinking silently:

A vampire… with power rivaling my own.

And a human from whom I sense no magic at all… is he hiding it?

Suppressing magic to this degree is nearly impossible.

At the same time, Y was analyzing the scene in silence:

Some of these demons bear marks…

And this woman… she’s a warning in herself.

Why would Lucarion come personally for an imprisoned demoness?

Is the contract inactive? And does it involve her?

Y’s gaze met Lucarion’s.

In that exact instant,

the same conclusion formed in both their minds:

This person… is dangerous.

Lucarion broke the silence.

“I will not repeat myself.”

“Why are you here?”

(Let’s see what he says.)

Y smiled faintly.

(He’s testing us.)

Then he spoke calmly:

“I heard there’s a way to kill you… without defeating you.”

“Is that true?”

(How about this answer?)

Lucarion’s smile widened slightly.

“Interesting.”

“And what would that method be?”

(This human is clever… but he has no proof.)

Y replied without hesitation:

(He didn’t even flinch.)

“There’s no need to tell you.”

“You already know it.”

Lucarion narrowed his eyes.

“If you know it… then why not show us?”

(I never imagined humans could be this perceptive.)

Y slowly lowered the woman to the ground.

“If you insist—”

Suddenly—

Y vanished.

In the same instant, he appeared directly in front of Lucarion

and struck with his bare fist—

But an invisible wall manifested at once,

blocking the blow without even trembling.

Y disappeared again

and returned to his original position,

as if nothing had happened.

Lucarion stared coldly.

(This human… is truly irritating.)

(Out of all options, he chose to attack barehanded.)

L formed a sideways smile.

(I’d bet the Demon King is deeply annoyed.)

(He expected to be cornered… honestly, Y.)

(Who would have thought I’d end up feeling pity for the Demon King himself?)

Y looked at Lucarion.

“Does that answer your question?”

Lucarion fell silent for a moment.

(I didn’t sense his movement…)

(And the wound on his body looks fresh.)

(Was this caused by the demon in the prison?)

(But that speed… impossible for an ordinary demon.)

Then he spoke:

“It seems you enjoy hiding secrets.”

“It is impossible for someone to conceal their magic to this extent.”

“Even the most disciplined beings…

their magic fluctuates, if only slightly.”

He paused, then added decisively:

“And that means…

you have no magic at all.”

Inside Y’s mind:

(The fastest one to reach that conclusion.)

He answered simply:

“That’s right.”

“I don’t have magic.”

Suddenly—

the air split sharply.

An invisible attack surged from behind toward Lucarion,

but his magical barrier blocked it instantly,

releasing a heavy echo that reverberated through the two colliding domains.

Lucarion’s expression shifted for a brief moment.

“Wind magic…?”

He said it quietly,

but the shock was unmistakable.

(Who did this?)

(It can’t be the vampire… which means—)

He slowly raised his gaze toward Y,

who was smiling faintly—far calmer than he should be.

(How did he do that?)

(I was certain he had no magic.)

Inside Y’s thoughts:

(I gained a fragment of wind magic…

when I fought Yamamoto.)

Lucarion finally spoke again:

“And it seems you specialize in concealing your abilities.”

(I’m certain he has no magic… but I have no proof.)

Then he added, staring directly at him:

“You humans… are truly troublesome.”

“But that is also your greatest strength.”

Y gave a brief smile.

“Thank you for the compliment.”

Lucarion returned to his question:

“So then…

why would a human and a vampire work together

to save a demon woman?”

Y and L exchanged a brief glance.

Then Y spoke calmly:

“Do we need a reason?”

Lucarion narrowed his eyes.

“Then you are an illogical person.”

Y replied simply:

“I’ve heard that a lot.”

Lucarion took a deep breath.

“In any case…

do you truly think I will allow this woman to leave?”

Y turned slightly away from him.

“That’s fine.”

“We didn’t ask for your permission to begin with.”

Then he said, as if concluding a trivial matter:

“Let’s go home.”

Suddenly—

a black mark appeared on Y’s hand.

He froze for a split second.

(So this is what she meant when she said the question was a trap.)

Lucarion spoke coldly:

“This is not a request… it is an order.”

“You are no different from demons here.”

“Anyone who bears my mark becomes my obedient servant.”

Then, in a decisive tone:

“Kneel.”

Y looked at the mark… then raised his eyes calmly.

“I’m not interested.”

In the next instant—

the mark vanished.

Lucarion unconsciously took a step back.

(It disappeared…?)

(Who is this man?)

Y spoke with a deadly calm:

“You specialize in contracts and seals… don’t you?”

Inside L’s thoughts:

(The contract activated the moment Y responded to him.)

Y continued:

“In any case…”

“The one who can bind my freedom

has not been born yet.”

Then he added, without raising his voice:

“And if you stand in my way…”

“I’ll free all the demons as well.”

Lucarion stared at him.

(He knows about my magic.)

(That woman must have told him… but how?)

(A professional deceiver.)

(No proof to confirm his words… and none to deny them.)

Suddenly—

Lucarion laughed.

A clear, genuine laugh.

“At last…”

“A foe worthy of being defeated.”

Then his tone changed.

“But it seems you’ve underestimated me… just a little.”

Suddenly, he shouted:

“Do you know… who I am?!”

At that very moment—

five demons collapsed dead before Y and L.

No movement.

No visible wounds.

The remaining demons recoiled in terror,

their formation shattering instantly.

L whispered anxiously:

“The Demon King… what is he—”

She stopped.

Her eyes widened.

A mark appeared on her hand.

At the same instant—

Y moved with blinding speed.

In a single motion, he drew his weapon

and severed the contract’s trace before it could complete.

He grabbed L and pulled her away—

saving her.

Lucarion smiled coldly.

“So… the weapon is the secret.”

L lowered her head slightly.

“I’m sorry… that was my mistake.”

Y shrugged calmly.

“No need to apologize.”

“Things just got more interesting.”

Suddenly—

dark strands of magic rose from the bodies of the five fallen demons

and surged toward Lucarion, sinking into him.

The Demon King’s domain began to expand,

as if space itself were bending to his will.

L spoke in a low voice:

“He’s absorbing the magic of the demons who died.”

Y narrowed his eyes.

“You really are devious.”

“And seal magic… that isn’t your true power, is it?”

Lucarion let out a light laugh.

“Look who’s talking.”

Y replied coldly:

“Seems we’re even, then.”

He leaned slightly toward L and whispered:

“Don’t speak.”

“Don’t say anything.”

“It looks like his magic is tied to words.”

L looked at him, then said with quiet resolve:

“Can you leave them to me?”

Y smiled.

“Of course.”

“But first…”

He paused.

“What do you prefer?”

“Do we fight together… or do I leave them to you alone?”

L smiled faintly.

“Is that even a question?”

“In any case… I’m no different from Ash.”

“Fighting beside you is all we ever want.”

Y answered sincerely:

“Hearing that always makes me happy.”

“I’ll do my best to make this journey enjoyable.”

Y and L stood side by side.

Y stepped forward.

“You have a strange kind of resolve.”

“Enough that you’re willing to start a fight right now.”

“And that makes me wonder…”

“Why are you doing this?”

Lucarion looked at him deeply.

“You are a strange human.”

“So strange that even the domain itself

fails to explain you.”

Y raised an eyebrow.

“Does that mean I’m special?”

Lucarion smiled, tinged with astonishment.

“Madly so.”

Then he continued:

“You know my magic.”

“And yet you speak to me as if I were your friend.”

“Even demons avoid talking to me.”

“And the mark on your hand appears… and disappears.”

Y replied with absolute calm:

“I don’t change the way I act because of magic.”

“No matter what kind it is.”

Lucarion took a step closer.

“Do you truly believe that a human without magic…”

“Can defeat a demon?”

Y met his gaze without hesitation.

“Let me ask you the same question.”

He paused for a single second.

“It’s always assumed that the Demon King is the strongest.”

“But what about you?”

“If you face a strong opponent in a one-of-a-kind battle…”

“…and they refuse to speak with you…”

“What would you do?”

Lucarion exhaled slowly, then answered in a tone devoid of emotion:

“Truly… the world has begun to change these past four months.”

He lifted his gaze slightly, as if tracing invisible threads in the air.

“First… the fox’s escape.”

“Then the failure of the assault on the Fairy Forest.”

“And now—”

He stopped, looking straight at Y.

“You.”

L glanced at Y for a moment.

He calmly rubbed his chin, a faint smile barely forming on his face.

(I wonder what he’d do… if he knew all of this was because of him.)

Y broke the silence:

“But why all of this?”

Lucarion met his gaze without hesitation.

“To defeat the Black Knight.”

Y’s expression shifted slightly.

“The Black Knight…?”

Lucarion replied calmly:

“You don’t know him? I don’t blame you.”

Then his voice grew heavier.

“Five hundred years ago…”

“The Demon King of that era gathered his entire army.”

“And marched to war.”

He paused.

“But halfway there—”

His tone slowed, deepened.

“A Black Knight appeared.”

The atmosphere itself seemed to change.

“A massive body… with only one arm.”

“And the battle began.”

Another pause.

“The demon army lost that war.”

“And the Demon King fell.”

Y raised his eyes calmly.

“He must have been powerful.”

Lucarion shook his head.

“Power was not the reason he won.”

“It was because he was… immortal.”

“He cannot die.”

Y’s gaze tightened slightly.

“And the Demon King who died was—”

“Yes.”

Lucarion said it without hesitation.

“He was my father.”

A brief silence followed.

Then he continued:

“For the past five hundred years…”

“I accumulated knowledge and experience.”

“And became the Demon King…”

“Through intellect before strength.”

His eyes narrowed.

“And I will be the one to break immortality…”

“And kill that man.”

Y nodded.

“I understand.”

Then he looked toward the woman and the girl.

“But what about the woman… and the child?”

Lucarion answered:

“Their story… is different.”

Y spoke clearly:

“We’re taking the woman and her daughter with us.”

Lucarion’s gaze changed.

“If you leave me no other choice…”

Then, in a single, unmistakable word:

“Blades.”

In the same instant—

Dozens of swords materialized from nothing

and shot toward Y and L.

They evaded smoothly.

Y spoke while moving:

“Word magic… becomes far more dangerous in your hands.”

Lucarion laughed.

“You say that as if it troubles me.”

“Five hundred years spent studying contracts.”

“Until I mastered them.”

Y narrowed his eyes.

“That explains a lot.”

“You fused contracts with word magic.”

Y charged toward Lucarion.

“Shield.”

A shield appeared from nothing,

blocking the attack head-on.

Y stepped back.

“This… is really annoying.”

Lucarion said coldly:

“I believed it was sufficient to defeat anyone.”

“But there are always exceptions.”

Y replied:

“Don’t say that.”

“Look around you.”

“No one wants to speak…”

“Because of your magic.”

Suddenly—

L appeared behind Lucarion.

“Shield!”

Lucarion shouted.

At the very same moment,

Y appeared behind him.

Y struck Lucarion’s back with a direct, powerful blow.

Y and L retreated together.

Y asked:

“What will you do now?”

Suddenly—

One of the observing demons collapsed dead,

a clear slash mark across his back.

Lucarion said calmly:

“This was inevitable.”

The dead demon’s energy surged toward Lucarion.

Y’s eyes widened slightly.

“I see.”

Then he said in a darker tone:

“Because of the contract…”

“You redirect damage to the other demons.”

“And with every demon that dies…”

“You take their magical energy.”

Inside L’s mind:

(So the demons here aren’t an army…)

(They’re prisoners sentenced to death.)

Lucarion looked at Y, his voice tinged with astonishment:

“I can barely sense your presence… and you call me annoying?”

Inside Y:

(This is a battle we can’t win.)

(We have to deceive him… but how?)

He paused.

(If only I had Lunaria’s magic…)

Suddenly—

He smiled.

Lucarion noticed immediately.

“He’s smiling.”

Y raised his head and said:

“Let’s start a new round.”

Y charged toward Lucarion.

“Blades!”

The swords appeared and launched forward,

but Y slipped past them with ease.

(The problem is that these swords aren’t magic… they can’t be copied.)

L emerged and released a direct burst of fire.

“Wall.”

A stone barrier rose instantly.

A massive explosion—

thick smoke filled the area.

From within the smoke—

Y burst forward, attempting an attack.

“Mountain.”

The ground surged beneath Lucarion.

“Gravity.”

The motion warped.

Y retreated instantly and pulled L close, shielding her.

(I have to force him to use light magic.)

Y raised his voice:

“You’re being lenient with us.”

Lucarion replied:

“No. You’re stalling.”

“If you abandon the woman and the child—”

Y cut him off immediately:

“No need to finish.”

“I refuse.”

Lucarion’s tone changed.

“Demons… attack.”

Y looked at L.

“Let’s move.”

⸻

A grand scene unfolded.

Y and L, united, stood against Lucarion’s army.

They advanced together,

cutting down demons one after another,

each protecting the other with near-perfect precision.

“Fireball.”

Dozens of blazing spheres appeared,

striking everything—

Y, L, and the demons alike.

Y and L retreated.

Lucarion spoke:

“Your resolve is strong.”

“But what about this…”

“Light Beam.”

Multiple rays shot forth.

Three struck Y directly.

He fell.

L continued fighting alone—

dodging, striking, resisting the army by herself.

Behind her,

Lucarion continued killing demons,

his magic growing stronger with every death.

He unleashed a massive attack toward L—

But suddenly—

Y appeared behind her,

grabbed her—

and vanished.

Lucarion froze.

“What happened?”

In the next instant—

Y and L reappeared beside the woman and her daughter.

Lucarion’s eyes widened.

“Instant teleportation?!”

“How did you do that?!”

Y didn’t answer.

He simply smiled,

then hurled a rock, blasting open a path toward the gate they had entered through.

Lucarion prepared a final light-based attack.

“State your name.”

Y said calmly:

“My name is Y.”

“Just a traveler.”

“Y…”

Lucarion repeated.

“If we meet again… prepare for defeat.”

Y smiled.

“Defeat?”

“No—prepare yourself.”

“Because I’ll turn your kingdom into my private garden.”

Just before the attack could reach them—

Y locked eyes with Lucarion and said:

“I have a message from Leo.”

“He says… thank you.”

And they vanished.

Lucarion stared at the gate in silence.

“Leo…”

Then he began to laugh.

With that laughter—

twisted black horns sprouted from his head,

and behind him unfurled pitch-dark wings, as though forged from shadow itself.

“So… it was you.”

“You’re the one who ruined my plans.”

“All this time, I believed I was the one controlling everything.”

A sharp smile cut across his face.

“Y…”

“A human without magic…”

“Yet with the cunning of a demon.”

He closed his eyes for a brief moment.

“If my father were still alive…”

“He would have truly enjoyed fighting you.”

They emerged outside the Demon Kingdom.

Ash was standing there,

demonic corpses scattered around her.

“Welcome back.”

L exhaled in relief.

“Finally… I can talk.”

“Was that a Lunaria technique?”

Y replied calmly:

“Yes.

I learned it—I just needed the right kind of magic.”

L looked at him.

“That’s why you let the light magic hit you.”

Ash asked:

“Who did you fight in there?”

L answered:

“The Demon King.”

Y turned to Ash.

“It seems he was the one who imprisoned you before.”

Ash nodded.

“No wonder that spell was so complex.”

L added:

“He’s intelligent.”

“He figured out that Y has no magic…”

“But he had no proof.”

Y smiled faintly.

“And that gives me room to move.”

Ash asked:

“And who are they?”

Y answered:

“A woman and her daughter.”

“They’ve been imprisoned for a long time.”

“And they seem to be important to Lucarion.”

Ash froze.

“Lucarion?”

L said:

“The Demon King’s name.”

Ash clenched her fist.

“Then… we need to move quickly.”

Y nodded calmly.

“That’s right.”

“We need to leave this place.”

He turned away without hesitation,

as if everything behind him had been nothing more than another step on a far longer journey.

Behind them, the Demon Kingdom still churned with magic and shadow—

but they were no longer part of it.

The group moved swiftly,

while a single name echoed in the distant silence…Y.