Betrayed by a hero in the dungeon, the Sword Saint encounters an elf girl deep underground—while being lavished with love by an elf who’s turned yandere, he exacts his revenge on the hero in a big, flashy “serves you right” fashion - Vol 1 Chapter 12
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- Betrayed by a hero in the dungeon, the Sword Saint encounters an elf girl deep underground—while being lavished with love by an elf who’s turned yandere, he exacts his revenge on the hero in a big, flashy “serves you right” fashion
- Vol 1 Chapter 12 - The Power of the Ancient Elf (Great Labyrinth Arc)
Vol 1 Chapter 12: The Power of the Ancient Elf (Great Labyrinth Arc)
As my consciousness sharpened and I sat up, I felt a faint discomfort in my right arm.
Looking down, I saw that my arm—on the verge of being torn off—was now reattached. No, it wasn’t just reattached…
“Who the hell did this…?”
From the shoulder down, my arm had been hanging by a thread, far beyond natural recovery. Even a healing mage specialized in mending fatal wounds wouldn’t have been able to fix this.
While I was pondering this, Yuu blushed and giggled, reassuring me without a hint of worry.
“The discomfort will fade soon.”
“Fade soon? Wait, don’t tell me… Yuu, did you do this? If so, that’s an incredible feat…”
“N-No, um… I used a method that only an Ancient Elf can perform. Rather than say I healed it… I guess you could say I ‘attached’ it?”
“‘Attached’ it?” I repeated in confusion.
Then Yuu dangled an arm in front of me.
It was the armored bastard’s arm—the very one I had severed earlier.
But somehow, there were… two of them. I was certain I had only cut off one of his arms.
Unable to understand the situation, I kept replaying Yuu’s words in my head.
“You attached it… using the power of the Ancient Elves…”
That power—the ability to transfer the “elements” contained within all matter.
Focusing on the idea of transfer, my mind began piecing together what Yuu had done.
And if my assumption was correct… this was nothing short of extraordinary. Shocked, I leaned in closer.
“Don’t tell me… you used that armored bastard’s arm to reattach mine!?”
“I-I’m sorry! B-But… it was the only way to save you…!”
“Ah, no! I’m not mad! I’m just… really shocked. I mean, it’s already attached, so it’s a weird question, but… is this really possible? And why isn’t there even a scar?”
My right arm showed no sign of a wound—nothing to indicate it had ever been severed. It was as if my original arm had never been cut.
Noticing my confusion, Yuu began explaining in order.
“As I mentioned, the magic of the Ancient Elves allows for the transfer of elements. So, I transferred the ‘attached’ element from that armored man’s intact left arm to your severed right arm, effectively swapping their properties. Since his left arm must have been at its limit… it ended up tearing off.”
Yuu spoke hesitantly, but what she had done was beyond comprehension.
In simple terms, she had taken the ‘state of being attached’ from the armored bastard’s left arm and applied it to my severed right arm.
Did Yuu even realize the godlike nature of what she had just done?
If the Ancient Elves had survived and continued researching this power, the possibilities—both for good and for absolute devastation—would be limitless.
There was a lot to think about, but right now, I should be grateful that she saved my life—and restored my arm.
As I struggled to find the right words, Yuu seemed about to say something, but before she could, I noticed the armored bastard lying nearby.
Was he still breathing?
I raised my hand to summon Asterion, but the armored man didn’t even twitch.
Had I finished him off with that last strike from my iron-mass blade? Or did Yuu drag him over here?
Noticing my gaze, Yuu simply said, “Ah,” and opened her mouth indifferently.
“If it’s that one, I delivered the finishing blow. Of course, since Kaim had already dealt a fatal wound, it was a simple matter.”
“Delivered the finishing blow? That couldn’t have been that easy…”
To think that even after having his arm severed and blasted away with an iron-mass sword, he still moved—he must have been an incredibly tough bastard. With my tactical insight, I never imagined that a staggering Yuu, who had just broken her seal and wasn’t fully recovered, could take him down on her own.
How did you defeat him? I asked, and she replied with a lack of interest.
“I defeated him with ordinary magic. Though, I’m not sure what level my magic is considered in this era.”
At the mention of magic, I glanced at the fallen armored bastard. On closer inspection, his entire body was charred black, and the parts that had been covered by armor had been blasted away.
His face was exposed, and upon closer look, it wasn’t that of a demon.
“Human…?”
Perhaps time had taken its toll, as some parts were corroded, but his face was unmistakably human.
Looking at him, Yuu said in a cold tone, “I have also accomplished one act of revenge.”
“The one lying there is one of the main culprits who sealed me away in the depths of darkness—one of the heroes of that time.”
“Though, he was an Undead,” she added, her tone tinged with regret.
I understood why from her next words, and at that moment I caught a glimpse of the profound darkness that this one girl, Yuu, carried within her.
“If a human were sealed away from dying like I was, I could have made them suffer before killing them… But with an Undead, who can no longer feel pain, I simply disposed of him quickly.”
“…I see.”
“Well, if it meant something for Kaim—the one who saved me and became my hope—I don’t mind at all!”
Her icy expression suddenly shifted, reflecting me in her dull green eyes as a slight blush colored her cheeks.
“If it meant something for Kaim—the one who saved me and became my hope—I couldn’t care less about someone I was starting to forget. Besides, because he tried to protect my seal while still in human form, Kaim managed to survive.”
“Hey, I…”
I began, then fell silent.
Yuu tilted her head, and from the hints in her eyes and every word, I sensed her dependence on me.
Having lived hundreds of years in the depths of darkness, longing for death, Yuu had finally found hope. I was prepared to accept such feelings.
Yet, what I felt from Yuu now was not something bright. Rather, it was imbued with darkness—so utterly opposed to light.
And as for the gaze and words directed at that armored bastard—no, rather, the former hero—they seemed to lack any real interest, yet carried unmistakable anger and a desire for revenge. There was darkness even there.
The vengeance I harbor for Sieg and the Demon King is fundamentally different. Whereas I only plan to get back at them and expose the truth to the world, what Yuu spoke of was “how to make them suffer.”
It was nothing short of vengeful malice—a darkness that sought to inflict such pain that the very act of living would become a source of regret.
If her thirst for revenge runs that deep, perhaps it would be better if it never existed. Clinging to the past like that would only imprison her rather than allowing her to move on with her life.
Frankly, it would only be a hindrance.
Perhaps, recalling my meeting with Nio, I felt tempted to counsel her to let go of that darkness. But the darkness Yuu harbors is the product of hundreds of years of loneliness and despair.
Even if I could persuade her to forgo death and embrace a purpose—escaping this place together—it wouldn’t be enough to dispel a darkness that could be called a bottomless abyss. We simply haven’t known each other long enough.
In the end, we brushed it off as if it were nothing, and Yuu finally seemed to find some relief.
“Well, as for me, I no longer have any pressing business. Weren’t you about to say something just now?”
At that, Yuu’s eyes suddenly sharpened. In her dull green eyes, I sensed an unfamiliar darkness that sent a chill down my spine, and I tensed up. Yet, without a hint of concern, Yuu slowly began to speak again.
“Earlier, when Kaim was falling, you mentioned someone named Nio. Do you know her?”
I had an overwhelming urge to ask why she had that look, but the mere mention of Nio’s name swept away all my doubts.
“…I know her.”
Still, from the chill I felt emanating from Yuu, I decided to regard her simply as an acquaintance.
For some reason, Nio-san has been carrying Asterion, pursued by demons, and it’s been two years since she vanished.
Honestly, I have no idea what she’s hiding, what she’s done, or rather, what kind of mess she’s gotten herself into.
Even so, after searching for two years without even hearing her name, I suppressed my eagerness and coolly asked, “So, what of it?”
“That little girl, right? The one with fair skin and wheat-colored hair?”
“…Yeah.”
Indeed, that is Nio-san. For some reason, Yuu knew her.
Resisting the urge to ask why, I listened intently to Yuu’s words.
There was no point in rushing—after two years of fruitless searching, I needed reliable information, so I kept my composure.
But Yuu’s mask was easily peeled away by her next words.
“I know where she is.”
Her unexpected answer left me utterly speechless, standing there dumbfounded.





































