Chapter 0: Seperation and Reunion

A good story needs a twist, after all. 

However, whether the characters in the story can enjoy that twist is entirely different. 

In most cases, a plot twist brings shock more than wonder. 

This time was no exception.

“Lies… Why are you here…?”

Lier, the Hero of the Sacred Sword, looked up at the throne of the Demon King’s castle with a face full of astonishment. 

The others were no different. 

The mighty northern dwarf warrior, Gareum, 

The ever-smiling saintess, Esther, 

And the stoic elf mage, Mana, 

All of them, without exception, wore expressions of disbelief as they widened their eyes.

There was only one reason. 

The face of the person standing on the throne, clad in armor, was so ‘unexpected.’

“It’s been a while, Lier Riosoul. Four months since we parted at the Aizenberg Gorge, right?”

“Cut the crap!!! Why are you here, Sien!?”

Lier roared in anger, his face contorted with fury. 

The flames on the Sacred Sword flared even higher, in sync with his turbulent emotions.

“Wait, don’t get worked up, Lier. This could be another of the enemy’s tricks.”

“Indeed. They might try to unsettle us with an illusion to gain a tactical advantage.”

Gareum and Mana tried to calm Lier with low voices. Yet, they too couldn’t completely hide the disturbance in their eyes. 

It was only natural. They, too, felt it. 

This was no illusion, no disguise, no trick of any kind. 

The man standing on the throne of the Demon King’s castle was undoubtedly their comrade, Sien Renos, with whom they had fought side by side for the past three years.

“This is impossible… You sacrificed yourself at the gorge to block the monster horde…”

“I didn’t sacrifice myself. I am the Demon King. Who could harm whom?”

Sien stated quietly. His familiar, calm, and resonant voice was the same as the one they had heard from their comrade, the magic swordsman, over the past three years. 

Except for one thing—the pronoun ‘I’ had changed to ‘She.’

“Was everything just a game to you…?

Did you laugh behind our backs while we struggled desperately to move forward…?!”

“……”

“Answer me!!!! Sien Lenos!!!!”

– Thud!!!

Unable to contain his rage, Lier slammed his Sacred Sword into the ground. 

Even with just that, the entire Demon King’s castle shook violently as if struck by an earthquake. 

But amidst the tremors, the man called Sien stood silently with his eyes closed.

Only after the storm had passed and the shaking had subsided did he speak.

“There was a prophecy.”

As if recalling a distant past.

“‘When the demons rise and the world is in peril, a hero chosen by the Sacred Sword will rise and stand against them.

Only he can fight the mighty Demon King on equal terms.’”

“What… does that mean?”

Saintess Esther cautiously asked. It was a prophecy directly given to their order by their god.

The Demon King Sien, still with his eyes closed, replied.

“It wasn’t difficult for that prophecy to reach me as well.

And it wasn’t long before I learned that a hero chosen by the Sacred Sword had indeed appeared, and even who it was.”

“……”

“And what do you think I felt when I heard that?”

He opened his eyes and looked at the party.

“The first thing I thought of was to kill you all. It’s best to nip potential problems in the bud before they can grow. 

In fact, at the start of your journey, you were so weak that you could barely handle a group of goblins.”

“…So you planned to do that?”

“But I soon realized that wouldn’t be the wise course of action,” Sien said, slowly shaking his head.

“There is a concept called a ‘self-fulfilling prophecy.’ It means that actions taken to avoid a prophecy can bring about the fulfillment of that very prophecy. 

I don’t take the existence of the god you believe in lightly. She is undoubtedly the greatest obstacle and adversary to me. 

Although she cannot directly intervene in this world due to unknown constraints, it is clear that her power is not to be underestimated. 

Could she have failed to consider the possibility that I might obtain the information and attempt to kill the hero early? 

Rather, wouldn’t she have woven a trick into the causal order, designed to activate in such a scenario? 

I couldn’t ignore that possibility.”

As he spoke, Sien opened his hand, a gesture he often used when explaining something to his party members.

“So, I decided to take a different approach.”

“A different approach…?”

By now, Lier’s voice had returned to its calm tone. He, too, was curious about why this intelligent man had approached them in the first place.

Sien nodded in response to his gaze.

“Yes. If you look closely, the prophecy only says ‘fight on equal terms,’ but it doesn’t say the hero will defeat the Demon King. 

Perhaps the goddess’s power wasn’t sufficient to ensure that outcome within the causal order. 

So, I thought: if I can’t prevent you from gaining power equal to mine, I should prepare for what comes after. 

I would create a momentary lapse in your concentration, a gap in your resolve, that could determine the outcome in a split second.”

“Ah…!”

Gareum let out a gasp. As an experienced warrior, he was the first to grasp the Demon King’s true intent. 

When two swordsmen of equal skill face each other, the outcome is often determined by factors beyond just skill alone.

Things like daily condition, differences in willpower, and small strokes of luck or misfortune can determine the winner and the loser. 

So, if one side fights with hesitation, thinking, ‘I must strike down a comrade with whom I’ve shared life and death…?’

“So that’s why you pretended to be one of our comrades. To shake our resolve at a critical moment like today with a cunning reveal.”

“Correct.”

At Sien’s straightforward admission, Gareum let out an uncomfortable cough. Beside him, Esther wore a look of shock. 

Mana, however, tilted her head in confusion and asked, “That’s strange. Then why are you telling us this so openly?”

“……”

“If what you’re saying is true, you shouldn’t be confessing this so boldly in front of us. Instead of creating hesitation, it would only provoke our anger. 

So why are you telling us everything so openly?”

It was a natural question, and Sien remained silent in response. 

Receiving the four’s suspicious gazes, he slowly began to speak.

“…We demons, fundamentally, have a weak concept of what you humans call ‘relationships.’ 

It’s not that we lack emotions. We feel anger, confusion, and joy just as you do. 

If it’s about basic emotions like happiness, anger, sorrow, and pleasure, those are very vividly present within us. 

However, they are limited to oneself and do not extend to others. 

Therefore, concepts like camaraderie, maternal love, friendship, and romance are foreign to us. 

Even if it’s one’s own child, we eliminate them if they cause harm. 

Even after knowing someone for over ten years, we can calmly stab them in the back if necessary. 

That’s who we are, and that’s what demons are.”

“That’s right,” Mana nodded. 

There was nothing particularly surprising about it. It was well-known information about demons, and it explained why strict hierarchical order was maintained in their society. 

But the next thing Sien said was unexpected.

“That’s why, in this ‘pretend comrade’ act, the only ones bearing the risk should have been you… 

Or so I initially thought.”

“…?”

Or so he thought… but maybe not? 

Mana, puzzled by this, noticed an emotion in Sien’s eyes in the next moment. 

An unmistakable sense of loneliness and regret.

“In short, the transformation magic was too perfect. 

Of course, it was necessary. If done halfway, there was a risk of being exposed, which would only provoke hostility instead of achieving the desired effect. 

So, I used all my power in the transformation magic to turn my body into a human. 

But that was the poison. 

Because I mimicked a human so perfectly, I began to feel human emotions as well. 

And so… I ended up feeling an emotion I’d never experienced before: ‘camaraderie.’”

“……”

“Let me confess honestly. I no longer want to kill you.”

At those words, a wave of unease spread through the group of heroes. 

Gareum closed his eyes softly, Esther clasped her hands to her chest, Mana tightened her grip on her staff, and Lier slightly lowered his raised sword. 

They all knew—there was no way they couldn’t know. 

The man before them was speaking with complete sincerity.

Because, in truth, they all felt the same way.

“In that case…” 

Lier, speaking on behalf of everyone, slowly began.

“Is there any way you could withdraw your army? If you still think of us as comrades…”

His tone carried a bit of appeal, and a hint of hope. 

But Sien, dashing those hopes, shook his head.

“No. You know as well as I do that we demons didn’t invade out of mere greed. 

It was a necessary decision to secure our right to survive as a species.”

“But still, if we take the time, maybe there’s a way…!”

“And do you think the other subordinates would accept that? 

To stop suddenly when we’re on the brink of world conquest?”

Sien let out a bitter laugh.

“Of course they wouldn’t. They’d attack me, claiming I’ve lost my edge under the hero’s sweet talk. 

Every single one of them, without exception.”

“That’s just the nature of demons,” Sien added.

And it was an undeniable truth. 

The demon society operates on strict hierarchy, but only as long as the ruler maintains the belief that they are benefiting the community. 

If a decision doesn’t make sense to them, they would rebel without hesitation, casting aside their previous loyalty.

“However, there is a way to establish a truce.”

“What!? Really?!”

“Of course.”

Sien extended his index finger, as he often did when explaining something.

“After much deliberation, I’ve found the solution. 

If all of humanity undergoes the transformation procedure to become demons.”

“?!”

Esther gasped, unable to believe what she had just heard. 

And it was understandable. 

A “Demonized Human” was a being created by injecting demonic or monstrous genes into a human body, turning them into a puppet. 

The hero’s party had struggled more than once against the special forces of the demonized soldiers. 

But to apply that procedure to all of humanity? 

Was he in his right mind?

“Of course, it’s not the same demonization that you have witnessed,” 

Sien quickly added, gauging their reactions. 

“The demonization up until now was designed for use as a weapon, with additional control spells embedded. 

But the demonization I am proposing would naturally exclude that part. 

It would preserve your free will entirely, altering only your physical form.”

“…But even so, what would that achieve?” 

“It’s simple logic. The reason demons and humans cannot coexist is that their living environments are radically different, 

like how terrestrial and aquatic creatures cannot inhabit the same space. 

Therefore, the solution is to transform the physical forms of all humanity to be like demons, so there would be no more conflicts. 

So that we can coexist and live together in the same demonic environment.”

Sien spoke slowly but with conviction. 

“This proposal isn’t entirely unfavorable to your species either. 

It’s well known that demons have superior physical abilities compared to humans. 

If all of humanity could gain the same benefits, wouldn’t that be a significant advancement for your species?”

“……….”

“Of course, there’s still the issue of how you can trust me. 

I cannot definitively prove that. I could be secretly planning to betray you while saying this. 

But I hope you can trust me, even without evidence. 

I’ll stake the three years we’ve spent together on it. 

Please, understand the sincerity of… no, of Sien Lenos.”

Sien’s voice was filled with deep desperation as he spoke. 

There was no falsehood in his words. 

And in reality, Sien’s proposal might indeed be the only solution for humans and demons to coexist. 

Even the most intelligent of the group, Mana, couldn’t come up with a better answer on the spot.

But.

“I’m sorry, but it’s impossible,” 

Esther was the first to shake her head. 

“Our bodies were crafted directly by God… 

so to defile them in such a way would be an unspeakable blasphemy. 

Therefore, I regret to say that I cannot agree.”

“Even if it means opposing me, you prioritize the word of your God?” 

“I’m sorry. But… I am a priestess.”

With that, Esther bowed her head, clearly expressing her sorrow. 

As unfortunate as it was, this was an issue of fundamental religious principles for her. She couldn’t be blamed for it. 

Following her, Gareum stepped forward.

“I oppose it as well. How could I possibly accept the idea of altering the body I’ve honed all these years into something else? Not only me, but my fellow tribesmen would also consider your proposal an insult.” 

With a dismissive snort, Gareum’s stance was clear—there was no room for discussion.

Sien, who had been quietly watching the two, turned his gaze to Mana, who stood beside them. 

“And what about you? I thought you, of all people, would understand that my proposal is rational.”

“…It’s true. I don’t particularly have any aversion to the idea of transforming my body. 

And I acknowledge that your proposed solution might be the only way for everyone to survive.”

“In that case…!”

“But no, it’s impossible.” 

Mana shook her head. 

“You know as well as I do that the best solution isn’t always the most ideal. 

Even if you and I agree, this plan can’t be implemented unless all of humanity consents to it equally. 

I can’t imagine that happening, and to suppress the inevitable resistance, there would be bloodshed. 

At that point, it wouldn’t be a ‘peaceful’ solution anymore. 

So, no. It won’t work.”

“….” 

Sien lowered his head in response to Mana’s calm rebuttal, understanding that she was right. 

He had come to realize this himself during his three years of living among humans.

Finally, after silently observing everything, the hero, Lier, spoke up. 

“Sien, can I ask you something?”

“What is it?”

“When a human is demonized, they become like demons in every way, right? 

Not just their biology… but their emotions as well.” 

Ah. Esther, who was standing behind him, let out a quiet gasp. 

But Lier continued, undeterred.

“I understand that you’ve thought deeply about us and have been searching for a solution. 

So, I’ll ask you this, considering all that. Could you abandon the emotions you’re feeling for us now— 

the ones that have been driving you, causing you to struggle?”

“Impossible,” 

Sien replied without hesitation.

“Right? I thought so,” 

Lier said with a bitter smile. 

“I don’t want to give them up either.”

“The adventures we’ve shared over the past three years have been experiences that I believe are irreplaceable. If I can no longer cherish them… I’d rather choose death.”

“I see.” 

Sien nodded, fully understanding, a bitter smile of resignation on his face. 

Then, he slowly drew the sword strapped to his back. 

“In that case… we have no choice but to fight.”

“…”

Lier gazed at the familiar purple blade they had seen countless times over the past three years. 

With a sorrowful expression, he asked, “I’ll ask one last time—do you have any intention of surrendering?”

“None.” 

Sien responded immediately, his smile returning—the same ‘rotten smile’ full of arrogant confidence he had shown throughout their journey. 

“After all, I still have my pride as a king.”

A week passed from that moment. 

For those seven days, they fought relentlessly, literally forgetting to eat, without a single moment of rest, pouring everything they had into the battle. 

The sky split open, the ground shattered. Two or three mountains were obliterated, and rivers evaporated entirely. The Demon King’s Castle, once thought to be the sturdiest in the demon realm, was completely destroyed without a trace. 

Mana, Esther, Gareum—Lier’s companions, who had supported him as the hero, fell one by one. 

Finally, only Sien and Lier remained.

“Cough…” 

“Huff, huff…!!” 

In the final moment, it was the hero who pierced the opponent’s vital spot.

“Heh, heh…! So this is the power of the hero directly chosen by the goddess…! To think that even I would fall…”

“Ha, ha… don’t make me laugh…!”

Lier, who had plunged the holy sword into Sien’s abdomen, staggered and collapsed.

“You could have fought more ruthlessly… like focusing on the weaker backline, or using soul magic to control one of our minds and turn us into puppets. But you didn’t do any of that, so… what are you…!”

“Ha, ha ha…” 

Sien chuckled upon hearing those words.

Despite having his stomach pierced, Sien let out a refreshing laugh, completely free of regret.

“That… that’s it. I fell victim to the very ‘gap in my heart’ that I mentioned last time. I guess this is what they mean when they say you get caught in your own trap.”

“Tch, don’t spout… such nonsense…!”

With those words, Lier, too, finally collapsed on the spot. 

He had exhausted all his strength and couldn’t even muster the energy to sit up.

Then came the silence.

Staring up at the dull, purple sky of the demon realm, Lier whispered softly. 

“…Sien.”

“What is it?”

“I’m sorry.”

Sien chuckled softly in response. 

“Sorry for what? You fulfilled your duty as a hero, and I fulfilled mine as the Demon King. It was an inevitable outcome. There’s no need to apologize for it.”

Sien continued, “I’ve always said that if you devise a plan rationally and do your absolute best with everything you can, then—”

“Was it really ‘no need to leave regrets behind’ that you meant?” Lier responded with a smile, echoing Sien’s familiar words from the past three years.

“Ah, so it was,” he thought. Indeed, the time they had spent together had not been in vain. Even if the beginning and the end were less than perfect, the journey in between had surely shone brightly.

Tears were now welling up in Lier’s eyes, tears he couldn’t even explain to himself.

“Lier.”

Sien’s voice echoed in his ear. Lier wiped his tears, rose, and looked at Sien.

The form of his dear friend was now slowly disintegrating into ash from the tips of his toes.

“Though I may never reach the ‘paradise’ you speak of, since I have severed ties with your goddess… still…”

In his fading consciousness, Sien squeezed out a final smile.

“If possible, we will surely meet again someday, my friend.”

This was undoubtedly the last words of the Demon King, or rather, Sien Lenos. With this final exchange, Lier wiped his tears and offered the best smile he could muster.

“Yes, we will definitely meet again someday!”

And with that reply, the consciousness of the Demon King faded away…

***

500 years later.

In the central temple of the holy city Ashtaria.

The girl looked quietly at the enormous statue of Lier, gleaming in the sunlight, and murmured, “I didn’t quite mean it in this form.”

Turning her back on the crowd cheering, “The next hero has descended!” she sighed.

“How did it come to this?”