The Demon King is unfathomable

Chapter 377 Functions!

“…I never expected to meet you here again, Miss Castellion,” Luo Yan said with a sigh as he looked into those bright, snow-white eyes. He knew he couldn’t hide from her any longer. “How is your father doing these days?”

Ophia smiled slightly and said politely.

"Just as when you left, he is still in good health. Also, he asked me to give you my regards when I see you, and to say that he misses the time we spent talking... By the way, I feel the same way; during the time you were away, I missed your voice and smile every single day."

Uh.

Is this how "音容笑貌" (yīn róng xiào mào) is used?

Luo Yan had no idea which book she had learned that from, but Professor Hector next to her looked like he was trying so hard not to laugh.

"I'm truly flattered. I don't recall ever making such a deep impression on Miss Castellón—"

"May I call you Ophia?"

"...It's not that it's impossible, it's just—"

"Thank you."

A satisfied smile appeared on Ophia's face, her long eyelashes curving like soft crescent moons, and her dignified and elegant demeanor rarely revealed a hint of relaxed playfulness.

Luo Yan didn't know how to respond to that, so he could only shrug his shoulders and use drinking tea to cover up his embarrassment.

At this moment, Professor Hector, who was sitting behind his desk watching the show, finally couldn't help but let out a gloating chuckle.

"Haha... It's so good to be young."

Seizing the opportune moment, he picked up his teacup, gestured with his chin toward the unopened letter on the table, and jokingly urged it on.

"Your Highness, the Duke of Castellón's personal letter is still on the table. Won't you take a look first? Don't neglect the Duke's good intentions."

Luo Yan glanced at him.

This old guy usually acts very serious, but he's actually quite sly inside.

He didn't say much, but reached out and picked up the letter of recommendation on the table, which was stamped with a bronze seahorse emblem in sealing wax. Throughout the journey from the Holy City to the northern wasteland, Ophia had kept the letter close to her body; the envelope seemed to still retain a trace of the girl's warmth.

Luo Yan removed the sealing wax and unfolded the letter.

The handwriting on the letter was strong and powerful, and it was written by the Duke André Castellion, who held sway over the holy city.

His Highness Prince Roxie Collin:
It's been a long time since we last met. I wonder how you've been?
More than a month has passed since you left, and the people of the holy city are all grateful for your generosity and benevolence, hoping that you can return to this land bathed in holy light as soon as possible.

I often hear the servants in the manor say that when Prince Colin was in the Holy City, it felt like something new was happening every day, making people unconsciously look forward to the next day.

Please allow me, on behalf of His Majesty the Emperor, to pay my sincerest respects for your contributions to the Holy City and the Empire!
Currently, the Templar Order's plans are progressing steadily and systematically. We have successively established over a dozen ports along the coast of the continent of Gana, and our expansion into the new world is in full swing. The only drawback is that Hell seems to have its eye on that fertile land, and a demon lord named Ig is rising on the northern coast. However, I believe that before the iron hooves of the Empire, that threat is utterly insignificant… not worth your worry.

In addition, the White Dew project, spearheaded by your distant relative Sir Dantes, is now on track.

The knight used debt as the main axis, leveraging the power of large landowners to eliminate bankrupt tenant farmers and small landowners. Once the large landowners were heavily indebted, he then used public opinion, the law, and the trap of debt to eliminate the large landowners who had lost the protection of feudal law, and incidentally taught a lesson to the greedy citizens... This land consolidation operation was so smooth and perfect that it truly broadened my horizons!
Currently, the syrup processing base managed by the Tantes Group has successfully commenced construction, and a new industrial park with high-quality rum as its core industry is rising from the ground on the outskirts of the holy city. The local residents are also grateful for your generosity; once the New World syrup is continuously supplied to the holy city, they will surely soon be able to live a prosperous life.

Another thing that delights me is that the project in the Báilau district, just as you promised, has visibly boosted trade volume in the port of Castellón! This strategy of using a core industry to drive the surrounding areas and engage in intensive production is truly a brilliant idea! On behalf of the people of the port of Castellón, I once again express my sincere admiration for your vision!
Furthermore, I heard that Your Highness was recently invited to become a tutor at the Academy, embarking on an exploration of magic and truth. When I heard this news, I was so surprised that I could hardly believe my ears—I never imagined that you had such profound attainments in the field of magic.

Saint Sis, is there anything in this world that you cannot do? Please share some of this favor with the Castellón family!

Haha! That was just a joke, Your Highness. I hope you won't take it to heart. The Castellion family has already benefited greatly from the Holy Light, and I sincerely wish you success in restoring the glory of the Colin family. I also believe what you said to me—that you will not keep this glory to yourself!
By the way, my youngest daughter, Ophia, has long been fascinated by the mysterious magic since she was a child. It would be wonderful if she could receive your personal guidance! I might not trust others, but I would trust you completely!

I'm entrusting my daughter to you!
Your most loyal friend,
Duke André Castellion

Luo Yan slowly folded the letter, his mind completely at ease.

On the surface, the letter was a letter of thanks and a request, but in reality, it was a carefully crafted and irresistible scheme by the Duke of Castellón.

It first affirmed its own contributions to the Holy City and Sir Dantès's merits by citing the enormous success of the White Dew District project. Then, it subtly hinted at the crucial role the Castellón family played behind the scenes.

Finally, it got straight to the point with the fewest words, promising Ophia with a favor, and sent her to him.

To be honest, what Luo Yan cared about wasn't Duke Castellion's harmless "scheming," but rather the "trouble" brought about by Ophia herself.

Her sudden appearance will undoubtedly bring uncontrollable variables to his carefully crafted "Prince Colin" story.

The biggest mistake in trying to have multiple partners is having them all in the same port. It may seem convenient, but it can lead to endless troubles.

It's difficult...

Seeing Prince Colin's troubled expression, Professor Hector felt an unprecedented sense of satisfaction.

Your boy also has today!
Clearly not intending to let Prince Colin get away with it so easily, he cleared his throat and interjected at just the right moment, giving Duke Castellón's daughter a helping hand.

“Your Highness, letters of recommendation are a tradition of our empire. You are a prince of the empire, and Duke Castellón is a pillar of the Holy City Senate. I think that since His Highness the Duke thinks so highly of you, you should grant his wish!”

Using the princess of the empire to "counterbalance" the prince of the empire is like using the spear of the empire to pierce the shield of the empire. Hector stroked his beard, feeling that his idea was extremely ingenious.

Ever since this prince entered the mage tower, he has either been exploiting him or leading him by the nose, and his imposing manner has completely suppressed him.

This time he finally got his revenge!
Seemingly noticing the fleeting trouble on Prince Colin's face, Ophia, who had been quietly observing him, spoke up considerately and softly.

“Your Highness, please don’t misunderstand. I’m just here to study magic and have no intention of causing you any trouble. I would be content if I could just sit in on your classes… If you really don’t want to see me, I… can just pretend I don’t exist.”

Being a Castellion girl after all, she vaguely sensed that the relationship between Prince Colin and Professor Hector was not as harmonious as it seemed on the surface.

Although she was pleased that Professor Hector spoke up for her, she did not want to become a spear in his hands.

In contrast, she would rather be His Highness's shield, making up for his shortcomings... just as her mother silently supported the Duke from behind.

Alright, alright, so you're using a strategic retreat to advance?

Luo Yan recognized the trick, of course, since he had used it many times and it always worked. He just didn't expect that Ophia had also learned it and used it on him.

I don't know who taught her that.

Seeing Professor Hector's barely suppressed grin, Luo Yan didn't want the old man to continue watching the spectacle, so he sighed and said...

“How could that be? Miss Ophia, even if I can ignore Professor Hector’s presence, I can’t ignore your beauty and charm.”

Completely unprepared for Prince Colin's sudden remark, Ophia's face instantly flushed red, like steam rising from a hot teapot.

Ignoring Professor Hector's glaring and blustering expression, Luo Yan glanced at the time on the wall and stood up from the sofa.

"Come with me, I'll take you to the lab."

Since Miss Castellón is prepared to "persist relentlessly," and even seems to have the support of her father, Duke Castellón, if I continue to treat her coldly as I did in the Holy City, I'm afraid I'll just be stepping into her comfort zone.

As a demon king who doesn't play by the rules, since Miss Ophia has played the retreat-to-advance card, he might as well "push his luck" a little.

Regardless of what Duke Castellón is planning, on the Demon King's territory, things must be done according to the Demon King's rhythm!
anyway--

He had to come up with a foolproof plan, either to settle Ophia in the academy or to find a way to make her give up.

In short, he absolutely could not let her stay by his side, and even less could he let her accompany him to the future "Duchy of Campbell," otherwise he really didn't know how to continue making up the story of the "lost prince who returned from overseas."

At this moment, Ophia had no idea how Prince Colin viewed her; she thought he was moved by her sincerity and persistence.

Happiness came so suddenly that she was caught off guard. She subconsciously hummed in agreement and hurriedly got up from the sofa.

Unexpectedly, this "unexpected reunion" ended so abruptly, leaving Hector greatly disappointed as he didn't get to enjoy the show.

He had assumed that after the whole "chase and chase" scenario involving stomach aches, Prince Colin would turn to him for help.

Then, after repeatedly declining, he could say, "I really can't do anything with you," and reluctantly accept Ophia, a disciple with exceptional talent, thus using his status as an elder to do a favor for the princes and dukes of the empire.

In the end, it had nothing to do with him anymore.

Are you kidding me?!

Luo Yan nodded to Professor Hector, said a brief "Goodbye," and then walked towards the office door.

Ophelia also bowed slightly to Professor Hector, then hurriedly followed him into the corridor.

Luo Yan, who was standing in the corridor, paused for two seconds, then suddenly thought of something and looked at Ophia and said.

"By the way, from now on, you are my apprentice. At least while we're in the Mage Tower, I'd like you to call me mentor, just like the other apprentices... Is that alright?"

"Ah."

Ophia blushed and nodded hastily, completely unaware that this was the second "um" she had said in a minute.

……

After leaving Professor Hector's office, Luo Yan took Ophia and went straight to the elevator, heading back towards the laboratory.

Ophia, who was standing next to him, was no longer as reserved as she had been in the professor's office. She was as lively as a lark that had been released from its cage, chattering incessantly beside him, asking all sorts of questions, and full of curiosity about everything in the school.

"Mentor, Professor Hector said you are studying 'arithmetic'?"

"I suppose so," Luo Yan replied casually, pulling himself out of his tangled thoughts. "Although I don't just study arithmetic, I occasionally teach my students other things as well."

"That's wonderful!" Ophia was even more delighted, her eyes sparkling with excitement. "My best subject at the Royal Academy of Arts is arithmetic! I'm sure I can be of great help to you!"

Ok?
Is there such a thing?

Luo Yan was slightly surprised.

He had always assumed that Ophia studied art, and even wondered how this duchess, with her "artistic talent" of embroidering a seahorse as Arachto, had been admitted to the Imperial Academy of Arts.

So it turns out the Imperial Academy of Arts doesn't just teach art, it teaches other things too.

As they got more into the conversation, Ophia slowed down and suddenly asked somewhat shyly in a low voice, "Um... Master, you didn't throw away the amulet I gave you before, did you?"

“Of course,” Luo Yan nodded with a smile and replied gentlemanly, “How could I forget something Miss Ophia gave me?”

He reached into the pocket of his robe and, without making a sound, took out the amulet that Ophia had sewn by hand from his storage ring.

Seeing that Prince Colin was carrying her talisman, Ophia's face immediately lit up with a relieved smile, and a blush rose to her cheeks.

"That's wonderful... The guardian dragon I embroidered for you is still here. It seems it's been protecting you well." A dragon?
Luo Yan was slightly taken aback, and looked down in surprise at the amulet in his hand again.

He had always believed that the crooked, abstract embroidery on the amulet was the emblem of the Castellón family—a bronze seahorse.

So it turns out it was Taphne?
Thank goodness Taf isn't here, otherwise that brat would definitely be spewing nonsense again.

“…Mentor?” Ophia tilted her head in confusion at Prince Colin’s strange expression, not understanding what was wrong with him all of a sudden.

"nothing."

Luo Yan stuffed the amulet back into his pocket, then looked at the "Magic Science" laboratory in front of him and changed the subject.

"Here we are."

……

The laboratory door opened, and the heated discussion paused slightly. All eyes turned to the entrance, especially to the young woman beside Prince Colin.

"Another one?" Jamie looked at the girl behind the instructor in surprise, his gaze drifting to Ram beside him. "And she's a new face... Have you seen her in class before?"

Ram shook his head slightly, looking at the girl with a suspicious gaze.

"No……"

She always felt that this woman didn't seem like a magic apprentice; her demeanor was out of place in this snowy plain, and she was more similar to Ilana.

Is it...

Is this person also from the Empire?
Luo Yan clapped his hands, attracting the attention of the busy apprentices, and introduced the situation with a smile.

"Ladies and gentlemen, this is Miss Ophia Castellón from the Holy City. From today onwards, she will be joining our laboratory as a prospective student... Please welcome her."

Scattered applause rose spontaneously, but quickly slowed down and eventually stopped without anyone noticing.

Castellón!
This surname, which was renowned throughout the empire, struck like a thunderbolt, instantly stunning all the apprentices present who came from commoner backgrounds.

They looked at the legendary duke's daughter with awe, momentarily at a loss for what to do, not even knowing where to put their hands.

To them, the Duke of Blackwood of Dragonwatch City was already a very important figure, but this man's father was far superior to the Duke of Blackwood.

The duke of the Holy City was on par with the king of a vassal state, but in reality, the former was clearly of higher status.

Luo Yan took in everyone's reactions and a faint smile appeared on his lips.

Although he didn't expect the other apprentices to have any malicious intentions in ostracizing Ophia, if the duchess herself couldn't stand it because she "couldn't fit in with the atmosphere of the scroll kings" and voluntarily returned to the Holy City, it would undoubtedly be a good thing for him.

However, Ophia's subsequent actions completely surprised him.

She showed no airs of nobility whatsoever. She first smiled and gave everyone an impeccable bow, then introduced herself in a gentle and appropriate voice.

"Hello everyone, my name is Ophelia Castellion. From today onwards, I will be your classmate and future colleague."

"To be honest, this is the first time I've come to such a far place, and the first time I've seen such heavy snow and such a tall tower... I am deeply shocked. I never imagined that the world outside the Holy City is so vast, and I never expected to meet such talented people like you on this unfamiliar land."

"I hope we can become good friends, not just apprentices working and learning together... Please give me more guidance in the future."

Applause rang out again in the laboratory, and this last round of applause was much louder than the previous ones; it was genuine applause from everyone.

The fact that the daughter of a duke could be so approachable truly surprised the Rhodes people present.

Let alone the Duke.

Back in their hometown, barons wouldn't even give them a second glance.

After finishing all this, Ophelia secretly glanced at Prince Colin beside her. When she saw the surprised look in his eyes, the corners of her mouth involuntarily curled up slightly.

come on--

Orphea!
Baron Corsia swallowed even lizardmen's excrement to survive, so what's a little thing like getting along with your classmates?

She was completely unaware of Prince Colin's malicious intentions, instead taking it as his first test of her.

Clearly, he wanted to see if he was qualified to be the assistant standing beside him.

So what she needs to do now is undoubtedly to build good relationships with her future "colleagues," and at least not be as spoiled as she was at the Royal College of Art.

Luo Yan would never guess what exactly inspired this young lady.

To be honest, he was quite surprised. It seemed that the Duchess had indeed undergone a lot of changes in the past three months.

That's a good thing, actually.

He had prepared for both possibilities: if he couldn't make Miss Ophia back down, he would find a way to keep her here.

As long as she doesn't follow me to the Principality of Campbell, it's fine.

Luo Yan gave Ophia an approving look, and after she finished exchanging pleasantries with her classmates, he briefly told her about things in the lab.

"You don't need to come here every day; for now, the focus is still on attending classes."

"Furthermore, you're three months behind the other apprentices. I don't know your foundation, but if you have absolutely no knowledge of magic, you're probably in for a tough time."

"You'll help me, won't you?" Ophia blinked her clear eyes, looking at him expectantly.

Luo Yan nodded politely.

"Of course, you can ask me anytime if there's anything you don't understand."

The laboratory was bustling with activity, and the relaxed and lively atmosphere returned.

Almost everyone was excitedly discussing the duke's daughter who had come from afar, speculating about her purpose for being there.

Ophelia's story quickly became the focus of discussion in the laboratory, and unlike ordinary nobles, Ophelia herself was happy to see people talking about her.

Of course, it's also possible that she saw it as some kind of "test".

Finally, seeing how easy the noble lady was to talk to, a bold apprentice mustered up the courage to ask.

"Miss Castellón...may I ask, why have you come to the Academy?"

"Well..."

Ophia glanced discreetly in Prince Colin's direction, watching his profile as he intently gazed at the magical tome, and smiled gently, winking.

"secret."

That bright smile made the taciturn young man blush instantly. He hurriedly bowed and thanked her, then turned and fled back into the chattering crowd.

In this rapidly warming atmosphere, only Ilana seemed somewhat distracted.

She wasn't interested in the gossip in the lab, but she did want to ask her supervisor questions a few times with her notes, though she never found the right opportunity.

Now, with Colin engrossed in flipping through magical texts, she was unsure whether she should go up and disturb him.

Her gaze kept drifting towards Colin, hoping to meet his eyes. And, as fate would have it, that burning gaze was caught by Ophia, who was basking in her own smugness.

Although Ilana herself saw it as a perfectly normal look of longing for knowledge, to those who lacked knowledge, that look took on a different meaning.

Especially that cool and beautiful face, which added an instinctive sense of vigilance to Ophia's suspicions.

Could this guy also be...?

Can't you?
That's her mentor.

While Ophia was thinking this, she forgot that she had just become Colin's apprentice.

Sitting behind his desk, Luo Yan finally noticed Ilana's hesitant look.

In fact, he had noticed it long ago, but he didn't want to interfere with the apprentices' own research, so he pretended not to see it.

However, with two pairs of eyes scanning him like radar, he couldn't sit still any longer. So he closed the magic book in his hand and walked to the workbench.

"You seem troubled by a problem you can't solve. Can you tell me what it is?"

Upon hearing her mentor's voice, Ilana abruptly raised her head, a hint of panic at being disturbed flashing across her face, but more so, the joy of finally getting her chance.

She handed over her notebook somewhat shyly, pointing to a page filled with dense calculations that looked like gibberish to outsiders, and said softly.

"I...I've encountered a problem I can't figure out...Professor. I'm thinking, since there's a way to find the extrema of a function, is there a simpler way to find the extrema of a 'function of a function'?"

Seemingly worried that His Highness Colin might not take this awkward and seemingly unnecessary question seriously, she quietly added a sentence afterward.

“You may find my idea a bit strange, but my intuition tells me that if we can solve this problem, it might help with the unfinished work of Mr. James Wally.”

It wasn't just intuition, but also her rational judgment.

James Wally attempted to build a system for analyzing magic using definite numbers, but lacked a mathematical language to describe the process.

Luo Yan took the notebook, his gaze falling on the calculations, a genuine surprise flashing in his eyes.

He hadn't expected Ilana to learn so quickly.

He had just explained the basic concepts of calculus in class, and she not only fully grasped what he had taught, but also took the initiative to delve into a field that he had not yet taught and that was far more difficult and complex than calculus!

This girl... might actually be a genius.

We've struck gold!
“Superfluous? Ilana, there is nothing ‘superfluous’ in this world, only mediocre people who cannot find the value behind the ordinary.”

A barely perceptible hint of joy flashed in Luo Yan's eyes. He put the notebook back on the table, looked at the bewildered Ilana, and said with praise.

"The question you raised is excellent. The so-called problem of finding the extrema of a function is another important branch of advanced mathematics."

"I call it a 'functional'!"

　My left middle finger has been shaking badly lately, and it's only one finger that's shaking. If there are any typos, please help me correct them.
　　
　
(End of this chapter)