The Mysterious Child: An Adventure Tale Beginning with Numerology

Lilith's fiancé?

Savey Akuninaru from the Magic Academy... that insufferable man said that as if to provoke me. (※It's just my imagination)

Certainly, Lilith is cute. Moreover, her every movement is beautiful, and she has grown into a refined child like a rose. Is she an angel or a goddess? Surely she must be the reincarnation of the goddess of beauty. (※It's just my imagination)

And he says he's Lilith's fiancé? What's with this guy, did his head explode because Lilith is too beautiful? There's a limit to delusions, to spout such arrogant nonsense in front of me, he's got some nerve. A tongue that doesn't know its place is unnecessary in this world, maybe I should chop it off with a mithril dagger--

> "Calm and Collected" has been activated.

...Well, you know?

Lilith is already 13 years old. As a daughter of a duke's family, it's not unusual for her to have a fiancé, right? I understand that.

But do you think I can accept it? Lilith is my beloved sister whom I've raised more preciously than anything else (※I didn't raise her). Although we've been apart for a long time, there hasn't been a night when I didn't think about Lilith. I won't allow her to marry anyone unless I approve. Specifically... well, someone who is as compassionate as a bodhisattva, modest, not arrogant, puts Lilith first, an extremely handsome man who's also strong in fights, full of a sense of justice, intelligent, and above all, can be considerate enough not to interfere with Lilith's and my relationship--

> "Calm and Collected" has been activated.

...W-well, certainly?

I can't decide who she marries. Father will decide everything, so my ideals won't come true.

But even if I take a step back, I think it's questionable to proudly declare it even if they are engaged. Certainly, Lilith is an angel and goddess that everyone would want to brag about, and even the magic mirror in fairy tales would be speechless at how she's the cutest in the world--

> "Calm and Collected" has been activated.

...Um, Senpai?

If I may ask, aren't you activating a bit more eagerly than usual--

> "Calm and Collected" has been activated.

...

Senpai, wait. Please, can I just talk for a moment--

> "Calm and Collected" has been activated.

...

> "Calm and Collected" has been activated.

I'm sorry! I'm really sorry!

It was my fault! I have a crappy brain circuit that overheats when it comes to Lilith! But really, from here on, I'll think calmly without relying on you, Senpai, so please watch over me.

> "Calm and Collected" was not activated.

Thank you for believing in me!

...Phew, I've managed to cool down for now. Senpai, you're really a senior.

Anyway, this male student Savey Akuninaru is Lilith's fiancé.

Well, seeing that Lilith doesn't deny it, it must be true. I've heard of the Akuninaru ducal family, so it's understandable in terms of status.

"Now then, everyone, let's start by handing out these cards."

Oops, while I was playing with Senpai in my head, the introductions of the other Magic Academy students had finished. I missed hearing them.

I'll remember their names and faces gradually. I can't memorize them all at once anyway.

"For those who are here for the first time, let me explain. These cards are record cards issued by the guild. They automatically record dungeon conquest information, so please keep them with you. The floors you've reached, the bosses you've defeated, and the monsters you've killed will be automatically recorded. You also can't use the transfer devices found every 10 floors without this card, so make sure not to lose it. We'll also record your entry and exit at the dungeon entrance on this, so please have it ready as we'll use it right away."

Tanya, speaking in a smooth tone, glanced at me and nodded.

"Ruruk-kun will explain the specific rules inside the dungeon later. There's almost no danger in the upper floors, so today's lecture will be while walking. Now then, please register here everyone."

Tanya, leading the students, walks to the reception. Lilith follows right behind, and then the Ladies' Academy students, Knight School students, and Magic Academy students follow in that order.

As I was absentmindedly watching them line up neatly, Mamared suddenly spoke.

"Ruruk-sama, it might be presumptuous of me, but there's one thing I'd like to mention. I have a skill called 'Body Temperature Perception' which is very useful for observing monsters."

"...Yes, and?"

"Although it's rude to interfere in others' love affairs... I think it might be quite difficult with Lilith-san."

"It's not like that!?"

Mamared was observant.

But indeed, because it was sudden, I lost my composure in panic, but I need to act properly as a teacher or I might slip up.

"It's understandable though. My sister also has extraordinary affection for Lilith-san."

"Eh? You mean Princess Margaria?"

"It's embarrassing to say, but she's quite devoted. On holidays, she's always going to Lilith-san's place, leaving the royal palace empty all day. ...Why does Father allow this... I want her to help more with my research..."

Mamared muttered her true feelings.

Even a princess is captivated, as expected of my sister.

Hehehe, I'm proud as her brother.

While conversing with Mamared like this, we teachers are at the back of the line, registering for the dungeon.

In front of the entrance stairs, we teachers now take the lead.

"Now for the final check before entering! Ruruk-sensei, Mamared-sensei, please."

"Yes. First, let me ask everyone a question. Who is entering a dungeon for the first time?"

When I asked, about half of the students raised their hands.

Those who aren't first-timers are the Ladies' Academy students and half of the Knight School students.

All the Magic Academy students are first-timers.

"Let me explain briefly. 'Dungeon' is a colloquial term, formally it's called a 'Labyrinthine Geo-zone Lifeform'."

Actually, I only learned this official name recently when the Guild Master taught me.

Apparently, it was named by the sages who founded the Adventurers' Guild. It was properly written in the documents too.

"In scientific classification, it's a unique species. You can think of it as a living place. Of course, as an ecosystem, it's independent... or rather, it doesn't reproduce. You can consider it just an academic name."

Some faces look uneasy upon hearing it's a living being.

But well, it rarely moves. Only during the awakening period.

"Dungeons around the world have various characteristics, but there are three main things common to their ecology. First, they attract living beings using minerals and magic essence. Second, they can produce monsters, and monsters that die inside the dungeon are instantly absorbed. Third, as you progress through the floors, the monsters that inhabit them become stronger, and the treasures generated become more valuable. By the way, the reason why all dungeons have these three features is said to be the same. Does anyone know why?"

"Yes."

When I asked, Lilith was the first to raise her hand.

"Then Lilith-san, please."

"Yes. I've heard that since dungeons can't change their body range as living beings, it's to efficiently increase the total amount of energy collected within the same range."

"Correct. The resources that dungeons initially possess are magic essence, spirit essence, soil, and minerals. To attract humans and monsters, which are energy sources or food for the dungeon, they must generate bait that has value for each species. At the same time, they need a means to prevent the bait from being taken easily. This becomes what we call the dungeon's 'rewards' and 'traps'. That's why good rewards are deep underground, and at the same time, effort is required to reach them."

"Teacher, may I ask a question?"

Margaria raised her hand swiftly.

"Go ahead, Princess Margaria."

"I've always wondered, how do dungeons know what's valuable to us humans? Do they have that level of intelligence?"

"That's a good question. Does anyone know the answer to this?"

When I asked, everyone shook their heads similarly.

Only Lilith might know. After all, Lilith is also a mystic arts user.

"You all know the dungeon's resources - that is, the conditions for their appearance, right? Magic essence deposits, large mineral veins, and spirit veins. Minerals and magic essence function as internal structure, traps, and bait. So what's the reason for needing the remaining spirit veins?"

"...Ah! I understand! It's the World Tree!"

"That's right. More precisely, it's the 'World Memory' in the World Tree. It contains and preserves all kinds of information, including the past. By the way, materializing that power through spirit veins is what we call thought manipulation in mystic arts. As a mystic arts user myself, I use that power."

"So the dungeons do too, don't they!"

"Yes. Dungeons obtain information about humans and monsters from the World Tree. That's why they can accurately produce rewards that we like."

This is something only mystic arts users can notice. Only mystic arts users can see and understand what kind of information the spirit veins spread throughout the dungeon are carrying.

"Thanks to this, we adventurers know that we can always find valuable things if we delve deep underground. That's why we risk our lives to conquer dungeons. Dreaming of striking it rich, driven by greed."

"Monsters are just as faithful to their desires," Mamared continues my words.

"Monsters are always seeking high-quality food. Recent research has shown that monsters can absorb magic essence without eating living beings. Therefore, the shallow floors of dungeons have less magic essence as food, while the deeper you go, the higher the magic essence, making it easier for them to grow and become stronger."

"You're all about to enter the dungeon, but please never let your guard down. Even in shallow floors, there are traps, and even weak monsters can be poisonous. Please never act on your own, okay?"

"Yes!"

"Now then everyone, we'll be lending out weapons from the guild. Those who don't have their own weapons, please make sure to equip either a sword, spear, shield, and definitely a short dagger."

Tanya, who had rolled out a large box from behind the reception, began distributing weapons to the Magic Academy and Ladies' Academy students.

"Mamared-sama, we have magic, so do we really need weapons at this point?"

"You must carry them in case you run out of magic power. And Savey-san, please call me 'teacher'."

"Yes~"

Savey reluctantly picked up a sword with a bored expression.

Indeed, for Magic Academy students, it's stronger and more convenient to fight with magic than weapons. Our little sheep didn't intend to carry a weapon from the start either, so I understand that feeling.

"Ruruk-kun, don't just nod, this is exactly when you should give proper instruction!"

"Sorry. One of our companions said the same thing, so I couldn't help it."

"Oh? So there's a pure magician in your party too?"

Savey asked, seeming somewhat pleased.

"Well, yes. We have one excellent one."

"Heh. Is that person in the 'Central Magic Association'?"

"No, no, they're just an adventurer."

"Hmm..."

Well, it seems they've been invited many times.

But Elenora is basically a muscle-head who dislikes hassle, so it doesn't seem like she'll join in the future.

Once everyone had chosen their weapons, I raised my voice to get their attention.

"Now everyone, we're about to enter the dungeon. Are you all prepared?"

"Yes!"

Some Magic Academy students look a bit anxious.

Well, people die frequently in dungeons after all. Although it's mostly mid-level adventurers, it's understandable to be nervous.

"However, today you're just observing, so please follow along and relax. Magic and weapons are forbidden except in emergencies."

"Today's plan is to go up to the 10th floor. Along the way, Ruruk-sama will fight, and I will explain the ecology and weaknesses of the monsters, so please remember carefully. Also, if you find any rare monsters, let me know immediately. Is that clear?"

Mamared is a bit intense. This is monster harassment.

And so, we led the students into the dungeon.

"--As you can see, Goblins have physical characteristics similar to humans. They have hearts, so when delivering a fatal blow, it's best to aim just below the chest. Ruruk-sama, please demonstrate."

"Here we go."

I quickly pierce the heart.

The Goblin instantly turned into materials.

"Horns and skin... no change in drop rate due to external wounds depending on location... but we need a few more samples based on weapon type... should I have Margaria carry a spear after all...?"

"Well, the basic materials Goblins drop are skin, bones, and horns. There are no rare drops."

As Mamared was muttering to herself, I explained while sheathing my short dagger.

We're already on the 9th floor of the dungeon. However, the monsters appearing are still only E-rank level, so defeating them as instructed is no trouble at all.

"By the way, since they're humanoid monsters, they use weapons normally. They're intelligent, so they understand the concept of blades, so be careful when confronting them. Mamared-sama, please explain the evolution information."

"Ahem, I apologize. The evolution condition is leveling up, progressing to Gray Goblin, Black Goblin, and King Goblin in order. Mutant individuals such as Red Goblin, Mad Goblin, and Zombie Goblin have been confirmed. While their strength and characteristics differ, their weaknesses remain the same."

"Mamared-sensei, I have a question. We've learned that Goblins often form groups. In group battles, what kind of magic is effective?"

"As there's no difference in elemental resistance except for mutant individuals, you can use whichever element you're most proficient in. Ruruk-sama, what examples do you have?"

"For those aspiring to be knights, you're assuming outdoor combat or defensive battles, right? Since you'll often fight in forests or villages, considering secondary damage, I recommend water, earth, or wind. Tactically, it's solid to use magic to hinder their movements and then use weapons to surely finish them off."

In reality, everyone uses similar strategies for exterminating Goblins and Orcs. Both knights and adventurers.

As the serious Knight School students were taking notes, Savey said with a bored expression:

"In group battles, can't we just use magic to wipe them out at once?"

"Intelligent monsters will even play dead. Even if you think you've annihilated them with area attacks, you might get stabbed by surprise by a Goblin hiding among its comrades' corpses and die."

"Ugh."

Savey grimaced.

Once you level up to a certain extent, Goblins might be easy to defeat as they're inferior.

But in actual battlefields, these things can certainly happen. This might be something that can't be understood just through classroom study or image training.

"Ruruk-sama, the next one is here."

"Indeed. Oh, this is rare. It's a Poison Slime."

What appeared was a purple slime.

Of course, it's an evolved form of Slime. It's not exactly a mutant individual, but it's a rare one in dungeons.

While Mamared was explaining about Slimes, I continued to avoid the Slime's attacks.

No matter how evolved, a Slime is still a Slime. It can only do slow body slams and spit poison, so I play around to buy time so the students don't lose interest. It reminds me of Punisuke from the old days.

"Now I'll explain elemental weaknesses. Ruruk-sama, the provided holy water please."

"Yes, here it is."

"Poison Slime is a dark and water elemental being. Its weaknesses are ice or holy attributes. For elemental monsters like Slimes, attacks of their weak element are very effective. Seeing is believing, please go ahead."

"Here goes!"

I sprinkled the holy water on the Poison Slime.

It seemed to melt with a splat, then immediately died and turned into materials.

Naturally, only poisonous mucus dropped.

"As you can see, even opponents that are hard to approach due to poison or appearance can sometimes be defeated with a single item. Knowledge about monsters is never wasted, so make sure to remember it well."

"Other easy conquest methods include using holy water on undead types, or tranquilizers on berserk monsters. Or rather, in the latter half of the dungeon, there are places you can't conquer without knowing these."

The students listened intently to our explanations.

Cardel had warned us to be careful because there are problem students every year, but these students are unexpectedly obedient. Even though some look older than me, there are no complaints or attempts to look down on us.

I thought maybe we could conduct classes for a year without any trouble -- and that's when it happened.

"Whoa! The floor boss is running backwards! You guys in the back, watch out!"

Just as we heard an adventurer's voice from the front, a one-eyed magical bull, a Catoblepas, appeared around the corner of the labyrinth.

If I remember correctly, the rare boss on the 10th floor was supposed to be a Catoblepas, right?

The Catoblepas, seemingly excited, was charging straight at us with heavy breathing.

I stepped a few paces forward, changing my position to prevent any impact on the students.

"Buoooooo!"

"Sorry, petrification doesn't work on me."

Well, it wouldn't work anyway due to the level difference.

I raised my hand to stop the charging Catoblepas with one hand--

"'Thunder Lance'!"

Magic was released from behind, hitting the Catoblepas directly.

The Catoblepas died in one hit and turned into materials.

When I turned around, Savey was grinning with a smug look on his face.