Preparations
The air flowed in a tranquil silence.
Within it, Jeron felt the gentle, drifting flow of mana.
As expected, the sheer volume of mana on the Karen Continent was in a completely different league compared to Earth.
When he had first sensed mana, he estimated the difference to be about tenfold. But now that he had fully awakened his mana and formed a circle, he realized the gap was closer to twenty or thirty times.
It was a figure that defied imagination.
A forest located slightly away from the county capital.
The family's soldiers and knights stood on strict guard around the perimeter. Although the county conducted regular subjugations, monsters could still emerge from the deep woods.
In fact, Jeron was secretly hoping a monster would show up. He was eager to test his magic in a real fight.
Fortunately or unfortunately, not a single beast had shown its face despite his hours of training.
Jeron drew wind-attribute mana from the circle near his heart.
A massive surge of mana traveled through his secondary circulatory system.
The moment the mana was drawn out, he shaped and processed the external mana.
Two Magic Missiles materialized in the empty air.
Had Count Hanes, who had taught Jeron magic, witnessed this, he would have fallen backward in shock.
Simply forming and controlling a single Magic Missile was a headache-inducing task, yet Jeron had performed dual casting through instantaneous mental arithmetic.
Jeron, currently maintaining the spell, did not fully grasp just how incredible dual casting was.
Unlike Jeron, who could perform mental arithmetic using Arabic numerals, the people of this era had to calculate using primitive methods.
His internal mana resonated with the external mana.
The external mana of the Karen Continent was too sparse to unleash significant power.
If he were to cast magic on Earth, it would likely be at least ten times more powerful than on the Karen Continent.
Jeron measured the distance to his targets and finished his calculations in an instant.
The targets were two massive trees about ten meters away.
He propelled the Magic Missiles forward with his mana.
Whoosh!
Though not as fast as arrows, they traveled at a high speed that would be difficult to dodge, striking the thick trunks.
Boom!
The centers of the trees shattered.
Crack!
Suddenly, the giant trees wobbled and began to fall.
Thud!
Wood chips scattered alongside a cloud of dust.
The sight of the two massive trees collapsing was nothing short of spectacular.
"Not bad."
Next, he cast different spells.
Jeron dual-cast Shield and Haste, both wind-attribute spells.
His movement speed suddenly increased by half, and a white barrier enveloped his body.
It was similar to the shields used by the mutants.
Jeron ran toward a ten-meter-tall tree and slammed his body into it.
Thud!
Thanks to the shield, he felt no impact at all.
At the same time, he slashed at the tree standing right next to him.
Slash!
The tree was cleanly severed.
Jeron's sword was forged from Earth steel.
The performance of Haste and Shield was quite satisfying.
Finally, Jeron cast the Dig spell.
A giant, translucent hand resembling a shovel materialized and dug into the earth.
In an instant, a pit over ten meters wide and three meters deep was created.
"This is useful too."
All the spells he had used so far were wind-attribute.
The first spell Jeron had learned was Magic Arrow.
This, too, was a wind-attribute spell, and it had become as familiar to him as if it were engraved in his mind.
Jeron had tried to use other attributes, but realized he lacked familiarity with them.
While he could have managed if he forced it, he needed spells he could use immediately. Thus, he had focused on mastering four spells:
Magic Arrow, Shield, Haste, and Dig.
All of them were highly practical.
In truth, he hadn't fully mastered their application yet.
He still struggled with calculations like measuring distance and hitting moving targets.
But what if the target was close?
Even a rough release of mana would deliver a solid blow, which was why he had focused on the manifestation of the magic itself.
"Whew."
Jeron gathered his mana back.
Then, sitting on the cleanly cut tree stump, he wrote down the facts he had gathered so far.
1. The mana stored in the heart's circle allows for approximately 20 spell casts.
2. When the circle's mana drops below 30%, mana depletion begins, affecting physical activity.
3. Magic is created through the resonance of internal and external mana. In other words, its power varies depending on the amount of external mana present.
4. The circle is unrelated to the mana of the Golden Key. However, they grow together.
5. As the mana circle was formed, the Golden Key also grew significantly. Even if he brings Kang Yu-jung from Earth, she can remain active for around 12 hours. The total weight of luggage he can bring from Earth is estimated to be 120 kg.
It was a highly positive change, but the path of a mage still felt long and arduous.
Even doing these calculations in his head was a massive headache.
For now, he didn't need quadratic functions, but the thought of having to calculate functions mentally in the near future made him feel overwhelmed.
Because of this, Jeron dedicated himself to solving math problems mentally every day.
He had asked Kang Yu-jung to write math problems for him, striving to make mental arithmetic a daily habit.
The only saving grace was that this body's brain wasn't half bad, allowing him to adapt quickly.
Jeron decided to wrap up today's training.
Since he had to cross over to Earth by evening, he needed to head back now and prepare.
"My lord!"
Sir Birken was riding toward him, leading the family's soldiers.
The knight's face was flushed with excitement as he galloped forward.
Having ridden through the scorching heat of the blazing sun, he was sunburnt, drenched in sweat, and looking rather disheveled.
"Sir Birken, what is it?"
"An urgent carrier pigeon has arrived from the capital!"
"Oh, is that so?"
The message carried by the pigeon contained two pieces of news.
[Trading rights approved. Effective immediately.]
[Royal Auction House access granted. Goods scheduled for sale in one week.]
"It seems Seria handled things well."
"We can now begin expanding the merchant group in earnest, my lord."
"First, our goal is to establish a firm foothold in the county. Then, we will expand our influence across the entire northern region."
"Yes, my lord!"
He wanted to expand the merchant group immediately, but realistically, it was difficult.
Although they had the proceeds from selling goods in the county, that alone wasn't enough to fund a massive expansion.
For now, they had to focus on developing the territory and producing local specialties.
Since there was a limit to what he could bring back from Earth, he had to push for luxury branding while filling the rest of the inventory with local products.
To do that, the territory itself had to develop to meet the demand.
Jeron intended to make a decisive move during this trip to Earth.
Not only would he rescue and bring back Mr. Kang, but he would also search the agricultural-industrial complex for viable seeds.
Furthermore, if he could raid bookstores or libraries to find a method for making porcelain, it would be a massive jackpot.
To qualify as a local specialty, it had to be produced within the barony.
Currently, the territory's specialties were limited to monster byproducts, herbs, and flowers.
If they could add high-quality flour and porcelain to the list, it would serve as a decent foundation.
He met Kang Yu-jung in front of the blacksmith shop.
People were still bustling in and out.
She was cooling off at a beverage shop across from the forge.
"Mister! Over here."
"Are you ready?"
"Yes. I made two crossbows and twenty iron bolts. I also made ten ankle traps, so the hunt should go well, right?"
"That's more than enough. Plus, we have our trump card."
"You mean magic?"
Jeron nodded.
Magic was indeed their ultimate weapon.
Looking back, wandering around Earth empty-handed had been incredibly reckless.
What would have happened if he had run into a mutant the moment he first stepped onto Earth?
He might have been torn limb from limb while standing there in a daze.
Compared to then, their current armament was exceptionally solid.
Now that he had met Kang Yu-jung and learned magic, he felt confident he could easily take down at least two mutants.
Jeron downed a bowl of cold water and headed into the blacksmith shop with Kang Yu-jung.
The stubborn craftsman they had met last time greeted them.
"Welcome, Baron! I was actually just about to send word to you."
"Is it finished?"
"Of course. We ran the forge day and night to get it done."
The heavily bearded blacksmith, contrary to his gruff appearance, rubbed his hands together and acted with utmost humility.
This was the power of money.
The blacksmith brought out the finished gears.
"We used the highest quality iron. We even mixed in some mithril, so the durability is excellent."
Kang Yu-jung took the gears and examined them closely.
The most critical factors for her were durability and dimensions.
If the dimensions were off by even a single millimeter, they might not fit the crossbow she was building.
Kang Yu-jung measured the dimensions precisely using a ruler she had brought from the stationery store.
Seeing her nod, the dimensions seemed to pass.
Next was durability.
To withstand a load of 800 kg, the gears had to be made of an incredibly strong metal. This was why they had spent a fortune to mix in mithril.
Mithril was a mysterious metal that did not exist on Earth.
It had a low melting point, making it easy to process, yet it was extremely strong.
However, pure mithril was astronomically expensive, so most "mithril gear" actually contained less than 0.5% of the metal.
Ting!
She tapped the gears against each other to check their strength.
"It's not bad. Though it falls far short of my expectations."
Fortunately, the blacksmith couldn't understand what Kang Yu-jung was saying.
Jeron didn't expect anything more either.
As long as it was made precisely to the blueprints and had decent durability, that was enough. Expecting perfection without using Earth-processed steel was simply greedy.
"To think that just mixing mithril with bronze yields this kind of strength. I wonder what would happen if we added mithril to Earth steel?"
Mithril was essentially a cheat code for this world's forging technology.
He was already looking forward to seeing what kind of incredible armaments could be created by combining mithril with modern metallurgy.
Jeron paid the blacksmith for the work.
"Good work."
"Oh, thank you so much! Please come again. Our shop is always open to you, Baron."
He probably wouldn't be seeing them again.
Once Mr. Kang crossed over, they would build a forge in the territory to produce iron goods themselves.
Returning to the inn, Jeron and Kang Yu-jung packed their bags and prepared to cross over to Earth.
To prepare for any unforeseen circumstances, they packed two days' worth of rations.
In addition, they packed the completed crossbows, ankle traps, bolts, a sniper rifle, two pistols with two magazines, a sword and shield, the mithril-alloy gear, cold-weather gear, hot packs, a portable burner, flashlights, and blankets.
Kang Yu-jung meticulously organized the luggage, and by the time all preparations were complete, evening had fallen.
"Yu-jung, are you ready?"
"Yes! I've done my absolute best."
He liked the phrase "done my best" much better than "perfect."
Steeling his resolve, Jeron opened the dimensional portal.