[Light of Heaven]

Downs had been a fast learner, and Lein no longer looked at him through the same prejudiced lens as before.

At first, Lein had always felt that he should only teach the kid magic at noon, because sooner or later, he was bound to be done for.

Now it seemed more likely that Lein, a mere mortal, simply couldn't understand the pace at which a genius grew.

For a disciple of this caliber, all Lein could say was: Bring on a billion more!

A master's attitude could change, too.

"Don't study any other magic today, and don't overdo it," he called from a distance before drifting away.

He had to leave in a hurry. Putting on the airs of a master could be exhausting sometimes.

Only after using a Fire Bat to confirm he was out of Downs's sensing range did Lein burst into laughter.

"Hahaha! I've struck it rich!"

System notifications scrolled rapidly across his retina.

This time, the Never Tire of Teaching system had spawned several subsystems.

The first was [Talent Detection]: within Lein's sensing range, all young disciples with magical potential would be highlighted and outlined on his retina.

Lein's grievances immediately resurfaced: he still couldn't leave the valley...

The second was [School Location]: for reasons Lein couldn't fathom, the system had decided that this godforsaken valley was the headquarters of the Never Tire of Teaching system. Teaching disciples here would double his teaching speed. The elemental sensitivity of both master and disciple would increase by 100%.

The third was the [Defense Department], which made Lein feel a little weird.

The Defense Department included:

[Surveillance System]: the Legendary Fire Bat King and 24 Fire Bats.

[Dragon-Headed School Gate]: hanging up a White Dragon's head could deter all enemies of high rank or lower.

[Active Defense Tower]: Tesla Tower. Its full-power range had a radius of 1.5 kilometers. Beyond that range, its ultimate killing power depended on the master.

The last was the [Elemental Pool], which gathered magical energy.

The Elemental Pool belonged to the school. As long as Lein stayed within the school grounds, he could freely draw on the pool's magical energy.

This neatly fixed the bug where he, a so-called Legendary Archmage, couldn't freely use magic.

What gave Lein a headache was that, for now, the Elemental Pool was more like a battery. He couldn't properly charge it with magical energy.

When he opened the Elemental Pool in the system, Lein gaped. There were only two ways to charge it at the moment:

First, during a thunderstorm, use the Tesla Tower to charge the Elemental Pool with magical energy.

Second, have a disciple provide it...

Well, poor Downs was charging the pool at a rate of five points of magical energy per hour. The pool's total capacity was one million points.

The problem was, even a random level-two spell required at least 500 points of magical energy. What was more infuriating was that, while the Elemental Pool was bound to him, the number of times he could use various spells each day was limited. And they had to be spells that either the master or a disciple knew how to cast...

If the system hadn't recognized the move Lein had used to kill the White Dragon as a level-seven evocation spell, [Greater Lightning Strike], his shoddy little school wouldn't even have had a powerful spell to guard the gate.

Lein looked away.

"Depending on the weather isn't reliable. I have to do something to speed up the Elemental Pool's charging."

He got right to it.

Since he didn't have to teach a disciple today, Lein plunged into the Blacksmith Shop and began making glass the old-fashioned way.

He had to admit, the abandoned Blacksmith Shop wasn't as bad as he'd imagined.

First, the furnace's temperature was wildly unscientific. It looked like a typical primitive furnace, yet it could easily reach 1,500 degrees Celsius.

Second, the glass that came out had fewer impurities than he'd expected.

Finally, the Blacksmith Shop's ventilation system seemed to contain some kind of force Lein couldn't detect.

Sigh! The end of science might well be magic and the supernatural.

Lein stopped thinking about it.

After more than a dozen attempts, Lein finally managed to make a halfway decent convex lens.

As he watched the huge lump of glass, nearly 60 centimeters in diameter and gradually cooling, he couldn't have been happier.

He didn't know how well the convex lens would work. If the Elemental Pool's description wasn't lying, then as long as he infused the ground at the center of the valley with a high enough concentration of light element, the pool could convert it into magical energy and store it.

The next day, Downs came bouncing over to Lein, hoping to continue his lessons, only to find that his master had gone up the mountain.

"Come on, give me a hand!"

The two of them hammered and tinkered for half an hour before they finally managed to mount the basin-sized convex lens on a Y-shaped metal frame.

"Master, is this the convex lens you mentioned?"

"Mm." Lein wiped away his sweat and smiled. "Downs, even though you think everything I do is magic, is it possible that what I'm doing isn't magic at all, but pure science?"

Downs's expression turned a little strange.

Seeing him lost in thought, Lein knew the kid was overthinking things again. Downs was seventeen, just the age to let his imagination run wild. Lein couldn't really blame him.

"Now, you've got to keep your feet on the ground. Don't spend all day dreaming of instant success. There aren't that many terrifying spells that can wipe out a whole crowd of enemies in one move. First, master the magic you already know..." Lein was lecturing when he suddenly heard the Fire Bat King's shriek.

Through their soul link, Lein knew exactly what it meant: an alarm!

"What!?"

"Master! Look over there!" Downs's voice trembled—a rare thing.

His good disciple wasn't some green recruit who'd never seen blood. He'd performed admirably in the battle at Ramanque City.

A battle-hardened mage was definitely far better in a fight than a pure academic who only knew how to study magic.

Following the direction Downs pointed and using his Eagle Eye Technique, Lein finally spotted the uninvited guests charging straight at them.

A huge group of...devils!

In the Chaos World, devils and demons were two different things.

The former belonged to the Lawful Evil alignment, while the latter were Chaotic Evil. Put simply, neither was any good, but devils followed rules and fought with organization and discipline, while demons were more numerous but liked to fight in a chaotic free-for-all.

Lein suddenly felt his mouth go dry.

At that moment, he finally understood that sometimes, being famous really was like being a fat pig—bound to get slaughtered.

Perhaps he'd managed to scare the human nations into leaving him alone.

But what about the other races that didn't play by the rules, even if the good-aligned ones did?

Being a neutral power wasn't easy.

If Lein were a vassal of some human nation, he could make someone else take the fall right now. After all, when the sky fell, the tallest person would hold it up.

But right now, he was the tallest person.

Along the narrow mountain path, a large troop of more than a hundred devils advanced in a long line.

The first one to reach the waterfall entrance was a man with the typical goat horns and reddish-brown skin. He looked disdainfully at the White Dragon's corpse, its eyes still open, and laughed.

He wore a gorgeous red velvet robe, with gold trim on the collar, cuffs, and elsewhere. The expensive rubies that adorned it were merely buttons.

With every step he took, he left behind a burning footprint, as if he were walking not along an icy mountain path, but through the fiery trails of Hell.

Behind him, two neat columns of devils stood in formation.

At the front were devils with green skin, stocky builds, and short limbs. Thanks to the devil bestiary Consultant Ganis had sent him last time, Lein recognized these fierce-looking creatures as Anzu Demons. According to the Adventurer's Guild's ratings, each one was a high-ranking devil that would take a high-level adventurer party averaging level seven to fight.

Yet there were at least twenty of them at a glance.

Behind them was a large group of devils that looked like hornets: Tiger Bee Demons. They weren't very strong—probably about as powerful as a Fire Bat—but their stingers were troublesome.

The system scan showed 218 devils in total, counting both types.

It was no exaggeration to say that an army of devils like this could destroy an earl's territory.

The man at the head of the troop was a half-devil, born of a human and a devil. He cleared his throat and spoke in a hoarse, unpleasant voice.

"Human mage! I am Falcao Mephist, child of the greatest devil, Annak Mephist! I care not who you are, nor what power you possess! I command you to submit to me at once, or the souls of you and your disciple will burn forever in Hell's flames!"

The answer to his swaggering proclamation was a beam of seven-colored light descending from above the clouds.

Without warning, the beam cut through the clear sky and fell upon the mountaintop. Then it bent at an uncanny angle and engulfed the fellow named Mephist.

The half-devil, who had just delivered his haughty ultimatum, suddenly froze.

The devils behind him stared up at the seven-colored beam descending from the heavens. They didn't recognize the master and disciple on the mountaintop, but they knew that kind of attack.

An overwhelming sense of unease fell over the entire troop. The feeling was far too familiar: a century ago, before the Holy Mountain of Light, an equally terrifying attack had shattered their bodies. Their wretched souls had been forced to return to Hell and start over as lowly little devils.

Who would have thought they'd see that attack again in this remote backwater?

"[Light of Heaven]!?"

The devils let out one agonized shriek after another. They wished they could shrink their massive bodies to the size of fists, or find some crack in the ground to crawl into.

Too late!

The seven-colored rainbow swept across the narrow mountain path, just wide enough for a carriage, and blasted the three-digit number of devils into dust.

When the swirling dust finally settled, what had become of the devil army?

All that remained in sight was a mountain path smeared with devil flesh and wreathed in Unholy Aura.

On the mountaintop, the master and disciple stared at each other.

"Downs, whether you believe me or not, this is really just a giant convex lens for focusing sunlight."

"Master, I understand. This is science, too!" His good disciple said the words, but his eyes clearly said, Yeah, right.