A Demon Lord’s Tale: Dungeons, Monster Girls, and Heartwarming Bliss

The Hero’s Assault

“What… is that?”

Nell continued advancing through the wicked forest until she arrived at a massive, gaping cave. Though the cave stood in the shadows of a steep cliff, it still somehow stood out to her. It appeared much darker than everything else around it, as if it was swallowing all the light in its vicinity and funneling it into some sort of deep abyss.

"Wait!" The hero's eyes shot open as she came to understand the cave's identity. "That's a dungeon!" She immediately drew Durandal, her holy sword, from the expensive-looking leather sheath on her waist. A single glance was enough to tell that the item was made by a highly skilled craftsman—it was both a beautiful work of art and as functional a scabbard as could be.

Durandal's faint, familiar glow was comforting. It mitigated her anxiety; seeing it allowed her to calm herself down.

Nell was already aware that her target was likely a demon lord, a dungeon master. One of the church's knights had filled her in on the details while handing down her orders. She was told that the demon she'd been tasked with killing was formidable. He lived in the Wicked Forest; his continued survival indicated that he was at least capable of fending off the powerful monsters that made it their home. The knight had mentioned that he probably lived near, but not in the Supreme Dragon's territory, and that she should if she encounter any foe that proved too powerful for her to defeat. She had even been provided a magic-imbued tool for that exact purpose.

Unfortunately for her, Nell's grasp on the status quo was lacking. It was both skewed and just flat out wrong. Raylow, Alfyro's lord, had seen demon first hand and confirmed that he was a demon lord, but since he was opposed to the expedition, he had failed to fill all the expedition forces in on all the details. All the reports he sent were half assed and lacked any real information.

Nell's only reliable source of information was the man that'd been removed from his position, the former commander of the Allysian Knight Order. He testified that the rest of the expedition force had likely been annihilated by a single male demon. The former knight captain's report was detailed, but as he retreated, he never witnessed the slaughter firsthand. There was no confirmation that the demon was as powerful as he seemed. Moreover, unlike Raylow, the former knight didn't know that the demon was linked to the Supreme Dragon.

Unlike the prince, who sat the top of the chain of command, the majority of those that served under him knew that the Supreme Dragon was no myth. Most of those in charge of military affairs knew that it acted exactly as described in the legends. It attacked everything that invaded its territory. The combination of that bit of knowledge and the fact that the demon was still alive was more than enough for Allysia's officers to infer that he likely lived outside the innermost sanctum. They were convinced that there was no way for him to survive an encounter with the dragon of which the legends were sung, regardless of how powerful he was.

"A-Alright, I guess this is it!" Nell nervously gulped.

A wave of cold air enveloped her as she stepped into the cave. Each and every single step she took echoed back to her and assaulted her ears with an unpleasant ring.

The cave was silent, too silent. Dungeons were supposed to contain monsters, but Nell had yet to meet even a single one. Her surroundings were so devoid of life that she found them eerie and sinister; a heavy sense of anxiety assaulted her being.

Though she felt uneasy, Nell pushed on until she arrived at the end of a cave and found a sort of door. The only word she could use to describe it was unnatural. It stood out from its surroundings, it was almost like it was artificial.

Nell immediately raised her guard. She inspected the door because she was concerned that it was laced with some sort of trap, but she couldn't find anything no matter how hard she looked, so she ended up up timidly placing her hand on the door's knob and giving it a twist. She then timidly pushed it open and looked beyond.

"Woah…"

An inadvertent sigh of admiration leaked from her mouth as her eyes fell upon the grassy plain that lay behind the out of place entranceway. Both it and the sky above it extended as far as the eye could see.

It was almost like the door she'd entered was a gate into another world. What lay beyond was so far outside her expectations that caused her to feel a sense of malaise. The part that stood out most, the single thing that left the biggest impression on her, was the massive black castle that stood at its centre.

The moment she looked upon it was the moment it burned itself into her memory. Its sheer size was overwhelming; the bulky, jet black structure looked to be at least twice the size of Allysia's royal castle. She didn't understand how, but gazing at it caused her to feel both disgust and appreciation. She was put off by the blackness of its material, but entranced by its beauty. The longer she stared, the hotter her chest burned.

“Amazing…”

She continued to observe the castle for a while, only suddenly snapped back to reality. She shook her head back and forth a few times to rid herself any unnecessary thoughts and forced herself to focus on the task at hand.

Nell finally began to understand that her hypothesis was correct. The cave really had been the dungeon's entrance. The reason she'd yet to be attacked was because it was just the prelude. Only now that she'd stepped through the door was the dungeon's master finally going to get serious.

She tightened her grip on her holy blade all the more as she narrowed her eyes, surveyed her surroundings, and advanced towards the castle's giant black gates.

***

I couldn't help but grin as I watched the hero stare down my castle.

"What manner of slovenly expression is that supposed to be?"

"Iunno know what you're talking about. "

Lefi's sharp glared caused me to return to my senses, so I quickly cleared my throat to cover it up. The dragon girl had recently christened the castle Luan Fionell Castle. According to her, the words meant "One that Reigns Supreme" in dragon tongue.

It was a good name; it made the castle seem impressive and majestic than it already was.

“Yuki…" Though I'd denied Lefi's claim, her gaze remained sharp. "It appears as you've no intention of ending the girl's life. ”

“Uh… what makes you think that?”

"One look at you is all I require to see that you lack the drive. I've witnessed what it is like for you to lust for blood, and the difference is immediately apparent. "

"I mean, you said yourself, so…"

"What? I fail to follow. "

"She's a girl. "

Though I declared that I would slay all my enemies, I didn't feel like killing the hero. Killing a woman was something that I knew would weigh on my conscience. I was more than capable of killing men in cold blood, but I couldn't bring myself to do the same to a young girl. That was simply how I'd started feeling about humans ever since coming to this world. To be exact, the rule applied to more than just humans. I felt the same way about everyone else that I didn't have a sort of pre-existing emotional investment in as well.

I long decided that I would kill those I wanted to kill and avoid killing those I didn't. And that the young girl that'd entered my dungeon fell into the latter of the two categories. I wasn't going to end her life because I knew that it would leave a bad taste in my mouth.

To that end, I was going to avoid activating my more deadly traps. I instead decided to focus on the non-lethal ones that would slowly but surely deprive her of her will to fight.

“Damned pervert…" said Lefi, as she pinched my arm.

“Ouch! T-That's not what I mean! L-Like, she only looks just little bit older than you, you know? Isn't it natural to hesitate about killing a girl that young?”

I spat out excuses in a hurry.

“Hmph…" Lefi twisted her expression into a pout. "Very well, do as you wish. But do know that I will not forgive you if you find yourself in peril as a result of this decision. "

“I-It’ll be fine. I'm pretty confident in the traps I have set up. Just kick back, relax, and watch. You'll see what I mean. "

I tried to cheer Lefi up and point her towards the video feed, but my efforts were to no avail. She just ended up glaring at me all the more.