High Elf Professor

Gildor sighed after he read the letter.

"Seriously? A professor? Me?" He muttered with disbelief.

He didn't even attend the magic academy! Now he was supposed to teach others?!

'Alright, I shouldn't get distracted while on a hunt.' He calmly thought.

Gildor Whiteleaf. An elf from the Whiteleaf family. A high elf, to be precise. He was sent to the demon border 10 years ago. A long time from the perspective of a human, but a mere passing moment in the eyes of an elf. And for a high elf, nothing but a blink of an eye.

Not for Gildor though. Though he was a high elf, he still kept his sense of time as a human. Which ended up being one of the disadvantages of choosing a different race for reincarnation.

But he couldn't complain! The high elf body he had was almost exactly as he ordered. Super-high magic capacity with a super-long lifespan. What was not to like?

Gildor closed his eyes and concentrated on the magic signatures. '50…? No, more like 60. Moving fast too. Are they mutated wolves?'

Winter nights on the other side of the "border" were quite calming. Most of the time. Red moonlight reflecting off snow-covered Forest of Nightmares… The sight made Gildor feel like he was living in a fantasy world!

Well, he was living in a fantasy world, and he was a frickin' high elf too. But it was hard to feel that in day-to-day life!

But wolves the size of four-story buildings, running inside a forest that was the literal manifestation of nightmares? Yes, that could only be something straight out of a fantasy!

Gildor paused condensing his mana for a moment and muttered. "I feel like I really should have a different reaction to this situation…"

Though he thought something was off, now wasn't the time; he shook his head and continued manifesting his magic.

By now, he had confirmation with his high elf eyes. The correct number was 61. And the building sized wolves had a metallic sheen on their fur. Coupled with the green smoke coming from their eyes, Gildor accurately judged their species as "Big Green-Eyed Metal Wolves."

'… I really should find better names for this stuff…'

Since no one else was bothering to classify these monsters, Gildor thought he should try. Mostly out of boredom. But unfortunately, cataloging monsters wasn't the engaging pastime he initially thought. As such, about over 90% of the monsters in his (WIP) encyclopedia still had placeholder names!

Finally, Gildor finished constructing his magic. At 500-kilometer range, he had to use quite a bit of his mana to kill a Big Green-Eyed Metal Wolf, even more for 61 of them. Thankfully, his "Really-Long-Range Death Ray" spell wasn't as inefficient as his "Really-Really-Long-Range Super Death Ray."

'… Sh*t, maybe she was right. Maybe I am bad at naming things.'

Gildor let the "Really-Long-Range Death Ray" loose with a sigh. Residue from the pitch-black mana really did create a ray in its wake. The main component though, was the small, pea sized structure. Even at great speed, the ever-changing trees on its path withered away, and the black soil underneath turned to dust.

The name "Death Ray" was really fitting for this spell, despite its particle like nature!

Only 3 seconds later, the pea sized magic structure hit the center of the group and exploded. Enormous death energies expanded in an instant and encompassed every single "Big Green-Eyed Metal Wolf."

61 energy signatures disappeared at the same time, along with anything else that was in the area, of course.

A long time ago, Gildor was rather concerned about damaging the Forest of Nightmares. But now, he knew that the small desert he created just now, would be swallowed in just a few days. The forest was just that tenacious!

And any living thing in it would be incarnation of all that is negative by definition. Suffice it to say, after a decade, Gildor's conscience was clear.

Still, he couldn't help but sigh.

'Why and how the f*ck did I get the Decay attribute…'

After his death, he only said he wanted to become an elf. To be fair, he was asked. By the Goddess. So it wasn't even a request! Rather, he was requested, by the Goddess, to say what he wanted!

As such, Gildor asked a few questions, and decided to become a high elf with high magic aptitude. The word "Decay" was never uttered in the conversation, nor did any of its synonyms!

Was it sheer luck, or was the Goddess messing with him? Considering how the Goddess called him a rounding error, and nonchalantly agreed to his wishes, Gildor doubted the latter. Pure luck, that was it. Probably.

After confirming nothing (of note) was left alive, Gildor nodded with satisfaction. His work was done for the day. Now he could go back and eat!

'Why did no one ever think of hunting on the other side before? Isn't pruning like this much more effective than waiting them to cross over?'

Those were his usual thoughts while crossing over the dimensional gap.

As the designated Sentinel, Gildor's temporary job was to watch over the demon border, and eliminate any and all threats. And that involved a lot of waiting around. It wasn't such a big deal for an elf, but for a human mind, it was mind bogglingly boring!

Covered in snow, a gray, majestic, and a little bit run down castle greeted Gildor as he came out of the dimensional gap.

Thankfully, Gildor's body was extremely resilient, and the temperatures that could freeze a human in less than a second only felt as if it was mildly chilly.

'Man am I glad for choosing an elf!' Gildor congratulated himself once again, as per usual.

Huge stone doors of the castle slowly opened up. Gildor, who was flying, paused in confusion. Since when he used the gates to enter and exit? He could fly! He was literally flying at that moment!

But his confusion didn't last long. Rows of knights appeared in formation and kneeled. Those weren't regular knights either; all of them had the Whiteleaf insignia on them.

'… Oh, they actually sent for me?'

The demon border was sustained by a few "volunteers" only. No one in their right mind would get even a thousand kilometers close to this place.

Gildor landed on the path covered by snow. Unfortunately, elves could not walk on top of snow. Not even high elves could. This discovery was devastating to the 4-year-old him. But thankfully, his skill over magic increased tremendously over time, and now he could walk on top of snow!

One way or another, he was going to get the True, Authentic Elf experience!

Dozens of knights kneeling on each side, silently welcomed Gildor to the castle. The sensation of people bowing, showing reverence and devotion, it had been 10 years since he last experienced it. This was what it meant to be a noble. Power that even those without power could have. Provided that they were born to the right parents!

Now that Gildor was close up, he couldn't help but notice the small black leaf underneath the white. A detail that he could've spotted while flying too, but because it was so unlikely, he didn't even think of looking for it.

Black leaves meant that these people were elites. And that meant…

"Little brother!!" A thundering voice came from inside. Though the voice carried the dignity befitting of a noble, the worry in it, was overwhelmingly obvious.

Gildor felt the mana ripple all around the castle. Snow started to melt from agitation, far away crows (that only elf ears could hear at this range) grew silent. Thick stench of the life attribute mana filled the void, and nearly made Gildor gag.

"Little brother!!!!"

Gildor knew it was useless to dodge, so he stood still and accepted his big brother's embrace.

To call Aldon Whiteleaf big brother was actually an understatement, because the age difference between them was over multiple centuries!

"Ugh, big brother, don't… can't brea-"

"I was so worried! How could you cross over on your own?!"

"Wait-"

"Shush! Let your big brother recharge his Gildorium supply! It's been ten years! I never could've imagined mere ten years could be such a long time!"

Gildor silently swallowed his frustration. '… I really shouldn't have taught them anime stuff. What was I thinking?'

One of the defining traits of all elves was physical contact between family members. Gildor was already used to it, but a decade was enough to make him temporarily forget some minor details.

Finally, Aldor freed Gildor from his embrace and deeply inspected him from head to toe.

"You've…" Surprise crept on Aldor's face, and soon it transformed into pride. "You've grown so much!" Then he hugged his little brother once more!

Gildor smiled. "Of course. I've been practicing every day!"

Suddenly, Gildor thought his big brother's embrace tightened, just a little. "Every day?" Aldor asked. "You've been crossing over… every day?"

"… Ha. Ha. How could that be?..." Feeling the odd gaze of his brother, Gildor decided to change the subject. "I received a letter, mentioning I need to go to… What did it say… An academy of sorts?"

Aldor released Gildor from his arms and sighed. "I guess mother could not resist and sent a letter herself." He sighed once more. "You have been stationed at the border for a decade; your duty is over. We were expecting you to return, but… Something unprecedented happened, and we are now in contact with another world."

Gildor nodded while intently listening, but his big brother didn't continue. He shook his head instead.

"Let us go inside, it is not good to talk about this without taking measures."

Gildor followed his brother. 'Considering you've even stopped using contractions I guess this must be a serious deal…'

Technically speaking, the so-called Demon Realm was also another world. Both worlds collided somewhat recently and caused quite a few disasters. The energy released by the collision was so huge that the dimensions eventually fused to each other, and created the demon border.

Though, saying that it happened recently wasn't particularly accurate. It did happen recently, but only from the perspective of an elf.

'If the last world that came into contact was the Demon Realm, what would this one be like?' Gildor wondered as they entered the inner sanctum. His brother Aldor led him through the maze-like corridors as if he knew the place like the back of his hand. '… Oh, right. He must've been stationed here when he was young. Duty of nobility and all that…'

Finally, they both entered the inner library. The one place in the rundown castle that reminded Gildor of his big brother.

"I will be honest, little brother…" Aldor leaned on a table and waved his hand. A mana bubble surrounded both of them, indicating that no one could listen in. At least, not without Aldor knowing. "… I've seen the humans of that world."

Gildor raised an eyebrow. "Humans?"

"Yes. Humans. It is a world originally filled with humans. Their world collided with another only a century ago. Similar phenomena occurred, but over time it got worse before it got any better." Aldor cupped his chin. "They made something called 'Interdimensional Alliance' and eventually recovered. The empress was impressed by the idea and ordered our family to investigate. I have stayed in their world for a few years."

"You've stayed with humans?" Gildor asked dubiously. His big brother had a sensitive nose even by high elf standards. He would avoid human dignitaries like a plague when they were in the empire!

Aldor's hand moved to his mouth. "…Yes." And imperceptibly shuddered. "It was not a pleasant experience. And Gildor, I am sorry. Your big brother has failed you."

Gildor felt there was something wrong, but Aldor continued.

"Empress…

…"

'… What about the empress?'

"She…

…"

'… What about the empress?!'

"… She has ordered our family to send a representative to the human world."

Gildor blinked in rapid succession. "Oh… So the professor thing…"

"Yes, you will act as a magic instructor for a short time. The royal order will contain the details, but your duty is to evaluate the humans, and this 'Interdimensional Alliance' that they have created."

Gildor raised his hand. "One question. Magic instructor? Me?"

Aldor nodded; his lips curled upwards with pride.

But Gildor frowned instead. "… You do realize my attribute is decay, right? And I can barely contain my mana. You know that, right?"

His big brother though, chuckled. "Even if you teach them our nursery rhymes that will be enough for them." His smiled tensed up, and a trace of disgust entered his eyes. "I have lived among them, Gildor, even if briefly. You must not lose hope. This mission is only for a short time! Mother will also push for your return while you are gone."

"… A-Are they that-"

"No. It is much worse." Said Aldor with vacant eyes. "They live in strange buildings made of mud and sticks. Most of the inhabitants have incoherent minds. Sounds or lights can make them abandon their sanity. Crime is rampant, yet they ignore it. Everyone steals from one another. The entire civilization… lives in a state of sustained cruelty!"

Aldor slammed his fist on the table!

"I… I cannot allow this! Gildor, I will take your place! You are simply too young-"

"Big brother." Gildor interrupted Aldor, knowing that if he let him continue, his big brother would certainly do something drastic. "This is empress' command, is it not? And if it was that dangerous, mother or father would've said something."

Aldor's eyes became moist, but his fists didn't relax.

"Didn't you say it was just for a short time?" Gildor pushed forward. "It'll be over before both of us know it!"

Finally, Aldor gave out a long sigh, hugged Gildor, and whispered. "If something happens, just wipe out all of them. Don't even ask questions. Got it?"

'… What?'

* * *

For the rest of the day, neither talked about the assignment, or the human world. Gildor realized his brother seemed to hold significant amount of trauma and did not press him for more details.

Since the mission was of utmost importance, the royal family had sent a teleportation device. All Gildor had to do was to active it. But before he did, it made sense to read the royal command first.

'… Ok, investigation, teaching, yeah, I figured it would be like this…' Then he read the part that mentioned the duration. '… 50… 50 f*cking years?! How the f*ck is that short-'

Gildor tightly shut his eyes and tried his utmost to contain his urge to scream.

'F*ck me…'

Though, once he gave it some thought, he realized the situation wasn't that bad.

First of all, he was a human in his previous life. An everyday paper salesman, with an incredibly average life. He didn't have the trepidation towards humans that most elves had.

Secondly, he had spent the last 10 years in this (nearly) abandoned castle. So what if he traded that for mud houses? If the city/village smelled like sewage, he could always move outside the city and "commute" to his job.

And finally, judging by his brother's attitude, the humans of that world were quite weak. And Gildor himself had a made-for-order high elf body with considerable magical abilities. Living there couldn't possible be more dangerous than living in this castle, let alone taking a nap in the Forest of Nightmares.

"Hmm… Not that bad, I guess. 50 years is fairly long, but, not that bad. Maybe…"

Gildor was only 25 years old. A regular elf of that age was considered nothing more than a small child. But as a high elf, he was already a young adult at the age of 15.

'Maybe I'll eventually get to know how to perceive time as an elf.'

As he did a final check on the castle, Gildor proceeded to toward the summoning chambers. His duty of protecting the border was nearly over. Two things remained. To leave a message for the future "generations," and greet the next Sentinel.

'A message… A message…'

Gildor fell into deep thought. Was the message important? Probably not. But after spending a decade here, leaving a message felt quite meaningful somehow.

'… A message…'

But he wasn't really good with words. Though he was a diligent student, he just felt that magic was much more interesting!

"Alright, let's just write…" His mana moved on its own and carved out the words. "The Empire must always have a Sentinel."

'… Sh*t, is it too corny?' After a brief moment of thought, Gildor shrugged. "Whatever."

He activated the summoning mechanism without an issue. Mana? He had plenty. The circle started glow, reminding Gildor of his first time in this place. Light flashed, castle shook for a moment, and then it was over.

Now, a young man was standing at the center, startled and disturbed. His eyes finally landed of Gildor after a moment.

"G-Greetings, Lord Gildor Whiteleaf." He bowed deeply, fully displaying his medium sized ears.

'… A normal elf?'

"This one is called Almar of the Iandan family."

'Iandan? Ah, right, a Viscount family.' Gildor was now sure that he really was a normal elf, and probably at least 60 years old, since that was when regular elves were considered young adults. 'Considering I know the existence of Iandan household, and this guy ended up here of all places, I guess their lineage must be extraordinary.'

Gildor gave a slight bow as greeting. "We do not need to mind our social ranks, as one Sentinel to the next. Call me Gildor. Just Gildor."

"Y-Yes. L-Lord, I mean, Gildor…" Almar felt that he it was a miracle that he could breathe!

What could anyone do when they meet a high elf with the legendary Decay attribute? Almar tried to stay calm, desperately.

But, Gildor Whiteleaf smiled! "I've been here for a decade, a quite… short amount of time, to be sure…"

Almar nodded. Of course, a high elf perceived time differently! A decade was indeed quite short, but Almar was sure that he couldn't even imagine how trivial a decade must be to a high elf! In fact, he was instantly convinced, that Gildor Whiteleaf was using the word "decade" entirely for his benefit! The legendary Decay attribute prodigy was empathizing!

Almar almost couldn't control his emotions! But he persevered, and continued listening.

"I did make some observations in this decade..." Lord Gildor Whiteleaf continued, oblivious to the effect of the word "decade" was making. "…Though you may assume this post in a more traditional manner, I would advise not waiting for the monsters. But going to them instead!"

"… Going to them?" Almar asked, truly not understanding what Lord Gildor Whiteleaf meant.

"Yes. Simply cross over, and prune the population before they could ever come to this side."

"C-Cross… Cross over?" Almar was doubtful if he heard Lord Gildor Whiteleaf right. But he quickly understood that this was a test. Yes, that was the most logical conclusion. A test! "But…" Almar silently gulped, hoping that he would give a right answer. "But isn't Forest of Nightmares on the other end of the gap?"

"Yes, that is correct."

Almar silently breathed a sigh of relief. With grown confidence, he continued. "And if I were to cross over, wouldn't I fall into a deep slumber?"

"Hmmm?" Lord Gildor Whiteleaf seemed surprised for a moment, but his eyes lit up in the next. "Ah, that? Yeah, that happens a few times, but you wake up quickly. You won't even feel sleepy once you get used to it."

Almar doubted his ears once more. Then he doubted his eyes, since Lord Gildor Whiteleaf gave him a thumbs up! Before he could re-examine the conversation from the start, the legendary high elf continued.

"I suggest practicing long range skills before you cross over. Your job will be much easier if you can detect big lifeforms inside a thousand-kilometer range. Then, you can simply pick them out from a distance."

Big lifeforms? Thousand-kilometer range? Picking them out? Almar kept listening with a sense of foreboding.

"You don't have to worry about damaging the forest. It will regenerate very quickly. All the mid-sized and below nightmares will regenerate too, so don't bother with eliminating them. They are just endless. But if you keep pruning the big ones, even the smallest demon or entity will stop crossing over."

Yes, Almar finally realized the issue. High elves, especially ones with extreme magic reserves like Lord Gildor Whiteleaf, could be influenced by their attributes.

Well, that was just a superstition that Almar didn't believe in. But now that he was listening how Lord Gildor Whiteleaf was explaining how to kill a horde of Archdemons from half a country away… The superstition suddenly became highly plausible!

"That's about it." Concluded Lord Gildor Whiteleaf. "Oh, also, I did write a catalog of the monsters I've encountered. But, they were so many, I didn't bother naming them properly. Now that you're the Sentinel, maybe you can continue that work."

Almar bowed on instinct upon seeing Lord Gildor Whiteleaf's shining smile. He silently swore that he would complete this mission, no matter the cost!

"Stop, no need for that, get up." Lord Gildor Whiteleaf said hurriedly. "Alright, I'm sure the border will be in good hands. You are officially the Sentinel now, so I won't keep you away from your duties."

After that, Lord Gildor Whiteleaf brought out a golden teleportation device, and activated it without hesitation. In the blink of an eye, Almar was alone.

The Demon Castle was now his temporary home.

He shook his head as gave a huge sigh of relief. His legs felt wobbly, and his head was almost spinning. Who could've thought meeting the previous Sentinel could be that intense?

Who said this was just a short assignment to instill a sense of duty for kids?! Almar wanted to smack his big brother on the head!

He moved from room to room, courtyard to courtyard, inspecting every inch of the giant castle. The place was mostly empty, except for the library, and the master's chambers. In the latter, he found a tome, bound in exceptionally hard, almost pitch-black leather.

"Demonic Beasts and Where to Find Them. By Gildor Whiteleaf…

It was real?!"

The tome was exceptionally thick, and its pages were exceptionally thin. Almar opened it in a daze and started randomly browsing it.

"Self-Devouring Thousand-Face Tentacle Tree with Flesh Bark?"

The drawing… Almar realized he didn't want to stare at it for any longer, he switched to the previous page.

"Self-Devouring Thousand-Face Tentacle Tree with Acidic Bark…"

Almar silently closed the tome once he realized that the tiny spot of ink below wasn't a mistake, but instead represented the scale of a regular elf.

He got up, and started moving around the castle, aimlessly. By chance, he ended up inside the summoning chambers, and spotted a freshly carved sentence at a corner.

"The Empire must always have a Sentinel..."

Almar, who had confidence in his sword skills, suddenly felt a tremendous burden. Could he really survive in this place?

"No." He shook his head. "I cannot think like that. I shall fulfill my duty, to the bitter end."

He smiled, eyes filled with determination and responsibility in equal measure.