None of the three could come up with an answer to my question.
It wasn’t that they lacked knowledge. For humans, the presence of mana was a fact of life. Even those who had nothing to do with magic knew that mana existed in the air. It was common sense. Hardly anyone would think to question something that existed so naturally.
"Now that you mention it, what happens to magic afterward? We use it as if it’s the most natural thing in the world, but..."
"It certainly is hard to explain... The more I think about it, the more mysterious it feels," Log added.
"Hmm, even you two don't know? When Big Sister Rain taught me magic, she never mentioned anything like that," Carol said, tilting her head.
All three of them seemed thoroughly confused.
"It’s only natural that you don’t know, so don’t take it to heart. This isn't the kind of thing people usually question. Even among Senior Explorers, I doubt you'd find anyone who knows the answer. I suspect Selma-san, Rain-san, and Lucre—the top magic users in the Silver Rabbit of the Night Sky—probably don’t know either."
"Even my sister...?"
"Probably. So, there’s no need to feel ashamed. You can become a top-class Explorer without knowing this. Conversely, knowing it won't suddenly make your magic skills skyrocket. In the end, what you actually do won't change. However, there's no doubt that if you understand this, you'll be able to handle magic well."
Why was I bringing this up during a lecture about Seirei? It was because Seirei and magic—and by extension, mana—were closely linked. I believed they would understand the concept better this way than if I simply explained what a Seirei was.
"I'm not blaming you, but you all felt like you understood magic, didn't you? In reality, your understanding is still shallow. But don’t let that get you down. If you don't know something, you just have to learn it from now on."
"""Yes!!!"""
The gloomy atmosphere that had settled over them began to lift, thanks to my follow-up.
"Well then, let’s get into the explanation. First, the answer to the question: what happens to magic once it has fulfilled its role? It—returns to mana."
"Returns to mana?" Log repeated.
"It’s easier to visualize if you think of mana as a 'versatile worker.' For example, when we activate a 【Fire Bullet】, from the mana’s perspective, it receives a command to 'move to the designated location while burning in a sphere,' and it executes that faithfully. Once it finishes that command, it enters a standby state until the next one comes. We call that standby state 'mana in the air.'"
Strictly speaking, there were specific conditions for returning to that state, but explaining them in detail would only cause confusion, so I skipped them.
"I always thought mana was consumed when magic was activated. So mana doesn't disappear, does it?" Sophie murmured, looking convinced.
They were all keeping up so far.
"This next part is a bit complicated, so just keep it in the back of your mind as I explain. Mana executes our spell formulas—our commands. If, hypothetically, the majority of the commands that mana usually received were Fire-type, what do you think would happen?"
As a side note, attack magic was divided into six systems: Fire, Water, Wind, Earth, Thunder, and Ice. Recovery and support magic also had systems, but those weren't relevant right now, so I left them out.
"Hmm, wouldn't it just be... nothing? I mean, it's just following orders, right?"
"Right. Nothing will happen after ten or twenty times. However, if that process is repeated a hundred or a thousand times, a certain change occurs in the mana."
"...Does it become unable to execute any other system's magic?" Log guessed.
"Close. The altered mana can still execute all systems. However, it becomes adept at executing that specific system. It's the same for us humans, right? If you do the same task repeatedly, you get used to it. Think of it like that. We call that altered mana a 'Seirei.'"
"Altered mana... Does that mean magic mediated through a Seirei would have faster activation speeds or higher power?" Sophie asked.
"Correct. Therefore, if there's a Seirei in the area, it's much more efficient to use magic of that specific system."
"I see. That’s a huge advantage if you know it... So, how do you check for the presence of these Seirei?"
"There is—no method to check."
"Eh...?"
"Seirei are fundamentally the same as mana. Since we humans can’t perceive mana, it’s only natural we can’t perceive Seirei, right?"
"Ehh, what kind of answer is that!" Carol complained, clearly feeling let down.
Well, it couldn't be helped.
"That's why I said it at the start. Even if you know this, your magic skills won't magically improve. But I also said that knowing this allows you to handle magic well. For Explorers who make their living in the Labyrinths, it’s definitely better to know."
"Ah, I see." Sophie seemed to have realized something.
"Sophie, what is it?" Log asked.
"Well, Seirei are mana that have executed the same system of magic thousands of times, right? And in a Labyrinth, the magic beasts on each floor are fixed. That means on a floor where most monsters are weak to Fire, wouldn't Fire-type Seirei be there? Because everyone would be using Fire-type magic."
"Hmm. They might be there, but does it really matter? If Fire is effective, everyone is going to use it anyway, whether they know about Seirei or not."
"What Carol is saying isn't wrong. But remember, Orun-san said you can use magic well. If there's a magic beast that requires ten units of power to defeat, you’d normally use ten units, right? But if there are Seirei present, even if you intend to use ten units, the actual output might be eleven or twelve. Looking at it the other way, it means you can defeat the beast even if you only use nine units of power. In other words, being able to achieve the same result with less power makes you that much more efficient!"
...Impressive. Sophie had explained almost exactly what I was about to say.
"Exactly. If you can suppress the power, the spell construction becomes easier, which reduces the strain on your brain. Knowing that makes a big difference!"
"Um, Orun-san, was my thinking correct?"
"Yeah, perfectly. I’m impressed you figured that out."
"Hmm? But then something is weird," Carol said, looking pensive.
"What's weird?"
"According to your explanation, Master, Seirei are basically just an extension of mana, right? Then what did that lady mean when she said, 'a Seirei taught me'?"
"Now that you mention it, that's true..."
"I hadn't explained that part yet."
"Hmm? What do you mean, Master?"
"As I said, Seirei cannot converse. But there are exceptions."
"Exceptions?"
"Right. Rare cases exist where a Seirei develops an ego. They are still classified as Seirei, but they are often referred to by a different name: 'Fairy.'"
"A Fairy? You mean like the ones from the fairy tales, who helped the Hero defeat the Evil God?"
"The very same. Though it seems only a tiny fraction of them have actually existed since the age of legends."
"Hmm? So that lady can talk to Fairies? But if Fairies are the same as Seirei, she shouldn't be able to perceive them either, right?"
"I’m sorry, but I can't speak on that. For now, that’s all for the explanation on Seirei. Just keep the concept in the back of your mind; it won't hurt to know it."
"""Thank you very much!"""
The day came to an end, filled with unexpected events like receiving presents from my disciples and giving a lecture on Seirei.
And then, the Martial Arts Tournament finally began.
Thank you for reading. The Martial Arts Tournament begins next chapter. I plan to keep the pace brisk and the rhythm steady, so the story might feel like it's moving faster than before. I hope you enjoy it!