"I'm useful, right?"
Aura came out of Serie's office full of life.
She clutched a stack of physical magic documents, leaned against the wall next to the exit with weak legs, and wiped the sweat from her forehead.
"As long as I'm useful, Serie won't kill me! If I don't want to end up as an experiment or if I want Serie to save me when Flamme and Frieren come after me, I must prove my worth."
Aura understood her situation well.
Everything was for survival.
"Lord Demon King, please forgive Aura!" Aura closed her eyes, shedding tears of pain and reluctance.
"All of this is for the sake of the demon race's great cause. That's why Aura endures the humiliation!"
"A demons without Aura is meaningless. The great cause of the demons cannot be accomplished without Aura."
"So, even if Aura is currently doing things that assist the enemy, you must believe that this is just an act that Aura was forced to do against her will. You must believe that this is just Aura's roundabout way to save the race! This is just a slight detour on the way to the inevitable victory of the demons!"
"With Aura around, the final victory will surely belong to the demons."
Aura opened her eyes, revealing a look of resilience and determination.
As one of the Seven Sages of Destruction and a pillar of the demon race, a major threat to humans, Aura had successfully infiltrated the stronghold of human mages and held the important position of librarian.
She had become the hope for the demon race to triumph over humans.
How could she, Aura, do nothing?
"Every day, I've been secretly slipping grimoires five hundred years out of date into the library, and even Serie hasn't noticed!"
Aura had learned from her previous mistake, where she had intentionally blacked out advanced magic knowledge, only to have Serie notice and highlight it.
This time, she had written books herself, scattering outdated magic systems that would only solidify the limited perspective of apprentice mages randomly throughout the vast library.
It was like placing mimic treasure chests among the library's collections. When those foolish humans found the treasure chests put by Aura from among the vast collection of books, they would open them with surprise. Then, they would find that the treasure chests did not contain treasures, but mimics that would cut off their future in magic.
This is a voluntary act of these humans and has nothing to do with her, Aura.
"Haha, hahaha, hahahaha!!"
"Teacher Aura, how do you solve this problem?"
"Cough cough cough... Don't call me Teacher!"
Aura, who was choking from laughing, immediately corrected the apprentice mage in front of her.
——As soon as Aura arrived at the main hall of the library, she was surrounded by a bunch of little human brats, asking her a lot of difficult questions about magic.
Oh, it's not appropriate to call them human brats. Those who have a preliminary understanding of magic are at least boys and girls of twelve or thirteen years old, and most of the apprentice mages who can step into the magic library to explore and study on their own are eighteen years old.
This is the time when humans are most rebellious during their growth period, and adults in the family often cannot control them. But in front of Aura, they are unnaturally well-behaved.
This was because—even though Aura looked young, her gaze and demeanor were like that of an adult who had lived many years. Often, a stern look from her would immediately subdue any mischievous young people in the library.
Apprentice mages who had been scolded by Aura all said that seeing Aura was like seeing a demon, and had the effect of stopping a child from crying.
However—
Even though Aura seemed stern, no apprentice mage disliked her.
Aura was always willing to help them solve their problems, and her explanations were always novel and advanced. Every mage who received guidance from Aura left with a sense of regret, thinking, "If only I had met a teacher like Aura earlier, my magical foundation might be more solid, instead of being as flawed and inefficient as Teacher Aura pointed out."
"Teacher Aura, last time you mentioned that the focus of defensive magic should be on shielding against magical attacks. But what should we do against physical attacks?"
"Are you stupid? How can physical attacks be faster than magical attacks? If the enemy uses physical attacks, you should know to use simple attack magic to preempt them. Sometimes the best defense is a good offense... And don't call me Teacher!!"
"Teacher Aura, lightning magic is obviously one of the fastest types of magic. Why am I always one step behind others when I cast it? You were standing by and watching during the last assessment. Can you give me some pointers?"
"Oh, you're the kid who used the violet lightning magic that day? The magic was beautiful but too flashy. What's the most important thing about offensive magic? It's simplicity! Why did you cast so many lightning bolts at once? One is enough! It would be faster and more stable... Damn, I told you not to call me Teacher!!"
"Teacher Aura, over here, over here! I'm researching an illusion magic project and encountered some difficulties. Mimicking appearance and actions is easy using the concept of mirroring. However, I encountered a bottleneck in simulating mana, and achieving perfection is always impossible. Can you help me point out where I went wrong?"
"Using mirroring to create illusions can only mimic physical forms. To synchronize mana changes, you must use projection magic... Wait, aren't you a first-class mage? Do your own homework! Get out! I'm not your Teacher!"
"..."
"Thank you, Teacher Aura!"
"Don't call me Teacher!"
Aura is indeed a well-informed demon with five hundred years of experience, and she has followed Serie for many years. Her understanding of human magic is incomparable to those humans who have not even lived to the age of fifty.
No matter how difficult the question, Aura could always hit the nail on the head with a single, concise sentence. Her responses often provided clarity in just two or three sentences, cutting through complexity and leaving her questioners with an expression of enlightenment. They would thank her as they left, their faces reflecting a mix of relief and realization, as if to say, "So that's it" or "Why didn't I think of that before?"
The apprentice mages who gathered around Aura in the library eventually dispersed after their sessions. Despite Aura's firm prohibition against addressing her as "Teacher," the young mages, who were receiving her instruction, respected the norms of etiquette. They would always bow humbly and refer to her as "Teacher Aura" before leaving, acknowledging her guidance and wisdom.
Most of the mages who frequented the library to study on their own hailed from commoner origins. Those of noble lineage, in contrast, typically maintained their own private collections of grimoires and would rarely visit a publicly accessible magic library.
The nobles would also secure specialized high-level mages to instruct and mentor their offspring. This approach ensured that their children did not face the same pitfalls as ordinary mages, who might take wrong turns in their studies and then seek out peers for guidance and exchange of ideas.
However, the presence of Aura, a top-tier mage, in the Magic Library had noticeably increased the number of noble mages visiting the public library. Dressed in opulent attire, these noble mages could frequently be seen within the library's walls. Occasionally, even princes and princesses, who were in the midst of their magical education, would arrive in grand carriages, seeking Aura's esteemed counsel.
The princes and the royal grandchildren, recognizing Aura's exceptional status, paid their respects by acknowledging her as both a teacher and a mentor, bridging the gap between nobility and the arcane wisdom she offered.
But Aura always treats everyone equally.
— She would angrily scold anyone who called her Teacher, regardless of their status.
Why was that?
Many believed it was because Aura, as a teacher, was humble and reserved, not good at expressing her true feelings.
After all, no matter how harshly she scolded, this lovely and respectable purple-haired woman always displayed patience, dedication, and a tireless commitment to teaching.
Everyone agreed: Aura is a good teacher.