[Side Story] The Day of the Final Battle

"Catherine. You actually believe that?"

Ariel stared at her with an expression of pure disbelief.

Catherine just beamed back at her with a wide, sunny grin.

"Of course not! It's just a song the bards have been wandering around singing lately. Sounded interesting, so I listened in."

"You juniors have some serious guts. Managing to act this relaxed in a situation like this."

The moment Charlotte scolded them, the two of them whistled in perfect unison and looked pointedly elsewhere, as if they'd rehearsed it.

"Charlotte is right. Everyone's letting their guard down far too much."

The pure-white Saintess spoke with quiet composure, and only then did a flicker of seriousness settle onto the two women's faces.

"The final battle is right in front of us. We should be a little more careful… r-right, Lily?"

Flushing pink across both cheeks, the Saintess edged closer to the silver-haired woman as she spoke.

Lily regarded the Saintess in silence for a moment, then looked away and began checking over her daggers.

"Nnh…"

Despite Lily's icy indifference, the Saintess's cheeks only burned a deeper red.

But before the Saintess could say another word, Haley raised her bow and dropped into a ready stance.

"The spirits are terrified. She's definitely somewhere in here."

Then she carefully drew up beside me and spoke.

"You're ready, right, Robin?"

At Haley's words, I steadied my heart and gave a quiet nod.

"It's time we ended this."

The moment I gripped the Holy Sword, radiant light began to seep out around me.

Holding that warm power close against my chest, I stepped toward the enormous doors looming ahead.

"Robin."

Catherine and Ariel latched onto either of my arms, both wearing the brightest smiles.

"Once we take down the Demon King safe and sound… you'll marry me. Got it?"

"Haha… what are you talking about, Catherine? Obviously I'm first. Right, Robin?"

Even in a moment this tense, the two of them bantered on without a care in the world for anyone else.

Smack—

""Hyaah!""

I gave each of them a light chop on the head. Both let out soft yelps and squeezed their eyes shut.

"Both of you, focus."

"Hiiing."

"Tch."

As I quietly approached the entrance, the rest of my companions fell in behind me.

"We're going in."

There was no time left to hesitate.

We had been fighting toward this day for years already.

Today—at last—we would defeat the Demon King and bring peace to this world.

.

.

.

How long had we been walking?

Countless powerful demons and monsters barred our path, but we were a hero's party tempered by battle after battle, experience stacked upon experience.

We cut through them with almost insulting ease and made it this far.

Myself, the Hero of the Holy Sword.

Ariel, the archmage who had reached 8-Circle magic.

Catherine, the beastkin known as the Fist King.

Haley, a high elf of noble birth.

Lily, called the greatest assassin in the Empire.

Charlotte, the imperial princess and genius strategist.

And the Saintess, blessed by the Goddess and gifted with a unique ability of her own.

Even if we wanted to lose, we couldn't. We were as close to an invincible party as it got.

We had clashed with the Demon King once before.

We'd been forced back then—but this time, the odds were clearly on our side.

I swore I would not let a single one of them be hurt. I would defeat the Demon King. And with that vow, I pressed forward.

"She's behind this door."

The Saintess spoke with a taut expression.

Only now did it seem to hit them for real. One by one, my companions swallowed dryly at her words.

I could feel it clearly.

The enormous presence waiting beyond this door.

The ruler of the demonkin. A cataclysmic existence called immortal.

The Demon King.

She was waiting ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠for us on the other side.

"…Hoo."

A cold bead of sweat slid down my back.

No matter how composed I usually was, right now my heart couldn't help but pound violently in my chest.

The time had come to bring years of journeying with my precious companions to an end.

The Holy Sword resonated, and a lovely voice flowed into my mind.

"Ruin."

Bolstered by her encouragement, I gripped the Holy Sword tight. The blade trembled as if delighted.

Right. Don't be afraid.

Believe. In myself, and in my companions.

In all the countless memories we've shared together.

I steeled myself and looked back at the others.

"Everyone ready?"

Tension marked their faces—but woven through it was a resolve born of ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠the unshakable trust they held in one another.

Confirming that all of them were prepared, I stepped forward and pushed open the enormous doors before us.

Creeeak—

What appeared as the doors swung wide was a vast interior steeped in darkness—and yet, for all its size, a space that felt hollow and empty.

Following the red carpet laid out from below, we found her.

Long crimson hair that seemed ready to spill all the way to her feet.

Vivid scarlet eyes that suited it perfectly.

And a pair of enormous wings and two mighty horns that mirrored the sheer weight of her presence.

Demon King Arbes.

She sat proudly upon her throne, looking down on us.

But…

"Who is that woman?"

Ariel had somehow drawn up beside me, staring toward the Demon King with a startled expression.

I felt the same confusion.

I was certain we had dealt with every last demon aside from the Demon King herself.

I shifted my gaze from the Demon King to the figure below.

Seated on the floor at the foot of the throne, resting her head against the ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠Demon King's knee and wearing a look of pure contentment as she received her caresses—an unidentified demonkin.

Her hair was a black deeper and sharper than the night sky itself.

The woman who had been purring against the Demon King's lap slowly turned her eyes toward us.

Her scarlet gaze locked straight onto ours.

"…Saint Wall!"

An indescribable emotion slammed into my heart.

A bone-chilling sensation wrapped around my body, and I instinctively raised the Holy Sword, erecting a sacred barrier around myself and my companions.

"…"

The woman frowned with one eyebrow, as if thoroughly displeased, and looked down at us.

Then she climbed up onto Arbes's lap and whispered softly into the Demon King's ear.

"My Demon King. May I handle them?"

The Demon King looked at her, a faint flush coloring her face for a moment—then let out a quiet laugh and stroked the woman's hair.

"Very well. Do whatever you wish."

Receiving the Demon King's permission, the woman slowly rose to her feet and began walking toward us, one step at a time.

The moment I saw her face, my mind went blank.

A beauty so sensual I had never once encountered anything like it.

My companions were all renowned beauties in their own right—women who could topple nations—but the aura radiating from the woman before me existed on an entirely different plane.

Some strange, unnameable feeling stirred as I looked at her, and fear came flooding into my body.

…Just what the hell is she?

I had never once heard of a demonkin who carried an atmosphere like this.

"Un…nie…?"

I followed the violently trembling voice from behind me.

Lily came into view—tears welling in her eyes, her body shaking in small, continuous tremors.

"Lily…?"

Until now, she had worn nothing but darkened eyes, never once expressing any emotion beyond her obsession with me.

Seeing her this shaken was nothing short of bewildering.

The woman regarded Lily in quiet stillness for a moment.

Then a bewitching smile touched her lips, and she extended a hand toward her.

"Lily. Come to your unnie."

"U…Unnie…"

Breath hitching, tears brimming, Lily began walking slowly toward the woman as if entranced.

"Lily!"

I reached out to stop her—but she slipped past my hand in an instant and moved to stand before the woman.

I tried to rush after her—

"Don't."

Sensing that something was deeply wrong, Charlotte stepped in front of me and blocked my path.

"Char! Lily's in dang—"

"Don't charge in recklessly. Remember that you're the core of this party, Robin. Leave this side to the Saintess."

"…Fine. I understand."

Faced with the absolute gravity in her expression, I squeezed my eyes shut and took a step back.

She was right.

The only one who could bring down the Demon King was me—the one who had inherited the Goddess's power.

If I lost my judgment and fell here, the world itself would be in danger that very day.

Judging by that woman's captivating aura and Lily's reaction…

Whatever had taken hold of Lily was almost certainly some kind of mental-type sorcery.

Leaving it to the Saintess was the correct call.

I looked toward the Saintess—

But the Saintess, too, ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠was simply staring at the two women, both cheeks flushed, breathing hard.

Anyone could see she was not in her right mind.

…Impossible. Even the Saintess, who bears the Goddess's Blessing, can't resist it?

I turned my head, dread rising, and looked back at the woman.

She was gently stroking Lily's hair in silence.

Lily could do nothing but weep endlessly beneath her touch.

"U…Unnie… I heard you were dead…"

"…That's right. I did die once. That's true."

The woman's eyes seethed for a brief instant—then went ice-cold just as quickly.

"That bitch destroyed everything I had. But it's all right, Lily. My Demon King saved me."

"The… Demon King…?"

As Lily tried to shift her trembling gaze toward the Demon King, the woman quickly caught her cheek and pressed a kiss to her forehead—

Chup—

Lily's eyes flew wide. The woman continued without missing a beat.

"Lily. Unnie hates humans. But not you."

With a strangely tender smile, she caressed both of Lily's cheeks.

"So, Lily. Will you stay by my side from now on?"

"I…"

Lily stared blankly at her for a moment.

Then, before long, with eyes that said anything was fine, she melted into the woman's arms.

"Yes. I'm always on Unnie's side."

"Good girl. My little sister."

The woman stroked Lily's hair once more, then started walking toward us again.

With every step she took closer, I felt some invisible snare tightening around me.

"…Ah."

Ruin's call finally dragged my reason back.

I bit down on my tongue to clear my head and checked on my companions.

Charlotte and Catherine. Haley and Ariel, and lastly the Saintess.

They hadn't fallen under the same spell as Lily—but they were drenched in sweat, as if fighting something off with everything they had.

"Everyone, get a grip!"

At my shout, their eyes finally snapped back to normal.

I ground my teeth once and fixed the woman with a hard stare.

"Who the hell are you?"

The woman looked at me and smiled—slow, seductive.

"Mm. As expected, the protagonist really is different."

"…What are you talking about?"

"Hmm… There's a reason for that."

Right. Whatever her identity, the fact that she was an enemy didn't change.

There was no need to hesitate any longer.

If I dragged this out any further, I had no idea what might become of me as well.

Even my unique ability, Indomitable Will, wasn't helping me at all right now.

In a voice quiet yet boiling underneath, I leveled the Holy Sword at her.

"I am Robin, Hero of the Holy Sword. For the peace of this world—I will defeat you."

At my words, the woman giggled—then gave me a neat little bow before answering.

"Fourth Legion Commander. Hesilaya."

Then she extended a hand toward me.

"I look forward to this, Hero."

Crimson mana surged forth in a vortex and came screaming toward me.