Low-Fantasy Occultist Isekai

Summoning a gust of wind, Nick vaulted over the stream, landing next to the stone he'd placed the potions on. He scanned each vial, making note of the subtle change in their hues and the gentle bubbling that signified proper cooling. Every detail mattered—if the potions were not stabilized, they could do more harm than good.

Satisfied that they had settled ideally and that the rituals hadn't affected them, Nick allowed himself a brief moment of relief. He carefully adjusted the cauldrons back into place so they could be separated into their containers for distribution among the soldiers.

Now, let's see what I got before Marthas gets here.

SPELL/SKILL

Vitality Drain (Intermediate): The original ability of a Moss Oni, this inherited skill allows the user to target either an area or an individual to drain them of their life force.

It was interesting that the System referred to it as an inherited skill. This meant that it interpreted extraction rituals used on monster cores as some kind of passing down, which opened the way for very interesting possibilities…

Before Nick could lose himself in speculation, soft steps reached his ears from behind a cluster of moss-laden pines. Rising slowly, he turned to face his latest observer.

"Everything in order?" Marthas asked, dipping his head towards the cauldrons.

"Yeah," Nick hummed in reply. "The potions are cooled and ready. They can be divided and sent out to the soldiers in a few more minutes."

Marthas nodded with approval. "Good. Now that we're together, my brothers and I will be able to heal any injury, but that doesn't mean we should be careless."

Before Nick could continue the meaningless conversation, Marthas' tone shifted abruptly. "Tell me, Nicholas, do you know what a dungeon core is?"

Nick blinked, momentarily disoriented by the sudden turn. He had his theories, and he would have loved nothing more than to finally get some clear answers, but he knew better than to expect Marthas to give up such valuable information without a reason. Gathering his thoughts, Nick answered with reluctant honesty.

"I read that a core is the crystallization that happens when a place reaches saturation of leyline mana. It's as if the ambient magic, once concentrated enough, creates a distinct, tangible entity." His eyes searched Marthas' face for any reaction.

The Prelate's lips curled into a wry, knowing smile. "Not entirely wrong, but that explanation is incomplete," he replied. "Dungeon cores are not mere byproducts of concentrated mana—they are the lynchpins of the System. They function as pivotal anchors, allowing whoever holds them to manipulate resources and energy in ways that defy the natural order."

The concept wasn't far from what Nick had suspected, but hearing it outright from a high-ranking priest, especially when it contradicted the temple doctrine, was quite surprising. In his lessons, the System was always presented as a divine gift, an abstract blessing bestowed upon the faithful from the heavens, never to be confused with the natural chaos of the world. However, Marthas' explanation painted a picture of dungeons as fundamental to the System's workings.

Considering how destructive they could be to humans… Well, the implications were many.

"Are you saying," Nick ventured, "that dungeon cores are like hosting points for the System? Its way of remaining anchored to the world?"

Marthas chuckled, a sound that was both amused and slightly dangerous. "Precisely. Just as the System recognizes a person upon receiving their class, a place is acknowledged when its mana reaches a critical threshold, crystallizing into a dungeon core. It is the System's way of marking an area of exceptional magical potential, which also binds it tighter to the world through the leylines."

"Any country," Nick said slowly, "would do just about anything to control dungeons then. They would gain access to resources and power in a way that nothing else can provide." He was a living example of this, having earned more levels during the expedition than in months before.

"That is exactly what the earthly powers desire," Marthas replied, "but heed this: a core that has been tainted—corrupted by the Feral Gods—is a dangerous liability. It might seem advantageous, but the cost of harnessing such power could be catastrophic." His voice dropped to a rumble, laced with an intensity that made Nick's hair stand on end. "I know what ambition can lead to. Do not be tempted to think of a core that is marred by corruption as a resource."

This book's true home is on another platform. Check it out there for the real experience.

At that moment, as Marthas' gaze flickered with barely restrained fire, Nick felt a chill of realization. The man before him harbored a burning determination to prevent corruption. He had dedicated his life to it. And he's capable of doing anything to prevent it from taking hold.

On one hand, the prospect of controlling a dungeon core was tantalizing. It was a gateway to unimaginable resources and arcane power, and he could only imagine what wondrous powers he could grant himself with it as a sacrifice. I could even become a living dungeon myself. I would have to be careful not to bind myself in place, but the things I could do with that much mana…

On the other hand, Marthas' warning resonated deeply with his own hard-earned experience. Sometimes, shortcuts to power existed, but if something felt too good to be true, it probably was. It doesn't help that he seems convinced the core is corrupted. I have no idea how to purify something so powerful. If it's really beyond saving, then even just using it as a source of mana would be foolish.

"Thank you for the warning," Nick said quietly, "but I have to ask, why come all this way to tell me this?"

Marthas' expression softened, though the dangerous glint in his eyes remained. "Because, Nick, you are not merely a soldier in our ranks," he said slowly. "You have been bestowed with incredible potential. My brothers have informed me of your heroic actions, and I do not want you to fall because of such a foolish mistake. As Floria's spiritual guide, it is my duty to ensure that you are well defended, not only from the external threats of fae and corrupted magic but from the inner temptations that such power brings."

In the quiet that followed, Nick looked down at his hands, still warm from the residual energy he had absorbed. He couldn't shake the feeling that Marthas had other motives. But if he suspected what I just did, he would have mentioned it. No, this must be disconnected.

Drawing a slow breath, Nick met his eyes and answered, "I understand. I will heed your counsel. If I happen to be the first to get to the core, I'll wait before doing anything with it." There, that should do it. Now leave me alone, scary old man.

Marthas' lips twitched into a semblance of a smile. "Good," he murmured. "It is good when the young heed the counsel of their elders. Too often do we have to resort to more drastic means."

Nick's stomach rumbled at the sight of the campfires, quickening his pace in anticipation of a hot meal. The savory aroma of spiced stew and reheated bread wafted toward him, inviting him into its warmth. He had cleaned up as best as he could and was pretty sure he had gotten rid of the worst alchemical smells.

I haven't eaten since this morning. High physical stats make food a much rarer necessity, but it's a fool who goes into battle on an empty stomach.

Nick would have gone directly to join his father, but he seemed to be in deep conversation with several soldiers, and he didn't want to intrude. However, he was intercepted by a surprisingly friendly face before he could sit down at an empty fire. "There you are," said Jack. With a genuine smile, he clapped Nick on the back and led him toward a log piled with food. "I've heard you saved more than just my ass today," he added, nodding toward the other men.

Nick's eyebrows rose in surprise at the sudden change of tone. Overcoming his initial hesitation, he managed a smile. "I'm glad I could help," he replied softly, accepting a steaming bowl of stew.

The other men appeared genuinely happy to have him join, so he didn't resist much, though it certainly wasn't what he had expected.

Taking his seat, Nick soon found himself engaged in conversation with a wiry scout with slitted eyes and a frankly unbelievable cheer, who introduced himself as Jasper. Between hearty spoonfuls of stew, Jasper leaned in conspiratorially. "You know," he began, "we managed to push much deeper than your group did before we had to retreat. Our unit encountered an entire army of Fae warriors. They just wouldn't stay down, but the Prelate unleashed this incredible firestorm that lit them up like a bonfire."

Nick's interest was piqued. "An entire army?" he echoed in surprise. Jasper nodded vigorously. "Yes, our job was to handle the weaker Fae on the outskirts and clear the path. But once we neared the heart of their formation, things got wild. I didn't think we would make it for the longest time, but he turned the tide with that massive spell. It was something out of a legend."

Leaning back, he continued, "But, you know, as cool as it was, we had to turn back after that, which was lame because I'm sure we would have made it to the core. Apparently, all the priests sensed something big going on on your end. The old man communed with what he called a Servant of Sashara. I didn't quite hear what he said, and the other priests kept mum about it. But if you saw what he did against those Fae knights with his fire, you'd trust him without a doubt."

"Ah, so that's what the column of fire was. I was wondering," Nick nodded, satisfied. He had no doubt that Marthas was capable of much more destruction than that, but to hear he'd single-handedly destroyed an army of fae knights was still something.

I wonder what the difference is between the members of the Wild Hunt and those other knights. The fact that our opponents were able to resurrect makes me think there's some sort of necromantic ritual at play, but I didn't sense any foul power...

"You haven't seen what old Arthur did to the giant Moss Oni!" An adventurer from a nearby fire interjected, earning jeers of approval from his companions.

"Those two don't count! Everyone knows Prestige classes are powerful. Winning when your enemy is stronger than you is much more impressive!" A soldier butted in.

A rather foolish contest over whose leader achieved the most impressive victory began then and was only resolved when the first rotation of the sentries returned and the second shift had to depart.

Throughout the night, Nick did his best to smooth over any lingering doubts the scouts might harbor about him, letting his CHA work its magic. To his surprise, Jack stepped in to introduce him to several other scouts. "This is Nick," he declared proudly, "the guy who saved my life. He's the best sensor I know." The introduction was met with nods and murmurs of approval; the irony was not lost on Nick. His very act of endangering Jack's life had, in a twist of fate, begun to reshape their opinion of him positively.

Amid the outlandish strategies and chuckling men, Nick felt a rare sense of belonging.

I'm not ready to make a decision yet. There is still a lot I need to do in Floria—the matter with the beastmen, first of all. But one day… Yeah, once I've done all I need, I'll leave.

As the camp grew quiet and the soft murmur of sleep began to take over, Nick curled up in the corner of a modest tent. His thoughts slowly surrendered to exhaustion, and he fell asleep.