Leaving the courtyard, Sunan headed towards the main building of the inner fortress.
Along the way, the patrolling soldiers greeted him with salutes.
To keep the secret, Sunan had his elder brother block the news of his becoming a Wizard Apprentice.
Because of this, the civilians and ordinary soldiers in Black Stone City knew little about Sunan, only that the lord's brother was somewhat reclusive, rarely venturing out.
Only the knights who knew the inside story truly revered Sunan.
Entering the main building, Sunan headed straight to the study on the third floor.
Except for when discussing with generals in the council hall, Kei usually handled affairs in the study or went to the training ground to practice martial arts.
According to his usual habits, at this time he should be in the study.
Just as he stepped onto the third-floor corridor, Sunan saw a beautiful maid walking out of the study.
Judging by her disheveled clothes, flushed cheeks, and damp hair, she had clearly just been through some intense exercise.
Seeing someone coming up, the maid turned her head, and upon realizing it was Sunan, she was startled, awkwardly saluting.
"Young Master Sunan."
Sunan looked at the maid strangely.
He vaguely remembered that this maid was a widow; he didn't think his elder brother would be into that.
"Go downstairs," Sunan waved his hand.
The maid hurriedly withdrew.
Sunan stood at the door for a moment, then pushed it open and walked in.
Kei, behind the desk, had already dressed and was engrossed in a book.
Hearing the door open, he looked up and smiled naturally, "It's Sunan, do you need something from your brother?"
Sunan didn't expose him and pulled a chair to sit down, asking, "How's the situation over at Black Stone Mine?"
"Very smoothly!"
At the mention of Black Stone Mine, Kei's face lit up with a smile.
"It's only been half a month, and we've already earned over a hundred gold coins by selling Black Stone Iron."
"This is just the beginning. As the mine's production further increases and stabilizes, the territory can earn at least four to five thousand gold coins annually just by selling Black Stone Iron!"
For a Viscount's territory, annual revenue is likely just four to five thousand gold coins.
Black Stone City, as a single city, has income comparable to a Viscount's territory, showcasing Black Stone Mine's gold-making prowess.
"What reaction is there from Flash City?" Sunan asked.
The movement at Black Stone Mine was too big to hide for long.
It's likely that Flash City already knows about the reopening of Black Stone Mine.
If Owen isn't foolish, he surely won't sit idly by and watch Black Stone City grow on the back of Black Stone Mine.
With a bit of forethought, it's clear he would attempt to block it.
Kei's smile faded, pondering, "The buyers of Black Stone Iron are mainly the lords and merchants from Thorn Flower Duchy. We aren't taking the route through Golden Rock Province, making it less easy for Owen to intercept."
The Thorn Flower Duchy is a duchy on par with the Starry Duchy, and its border happens to be adjacent to Black Stone City.
Trading with them means trade routes don't need to pass through Golden Rock Province to reach Black Stone City, alleviating concerns about Owen exploiting checkpoints along the way.
Of course, Owen could dispatch troops to cut off the route.
However, doing so would involve Thorn Flower Duchy, possibly changing the nature of the situation.
Unless absolutely necessary, Owen is unlikely to act impulsively.
Yet, caution is needed against other measures from him.
"I plan to form a cavalry," Kei suddenly said.
Sunan raised his eyebrows, quickly understanding.
The reason Owen holds the Baron title and suppresses the three other lords into silence is because he has a five-hundred-strong Elite Cavalry Legion.
Sooner or later, Black Stone City will face Owen, thus preparations must be made in advance.
The best response is to form an equally formidable army.
"It'll cost quite a bit," Sunan said.
Kei nodded, "Buying warhorses and armor will cost a fortune."
In these times, warhorses and armor are extremely expensive items.
Getting a warhorse and a suit of armor can't be done for less than thirty or forty gold coins.
Follow-up cavalry training, horse raising, and equipment maintenance are a huge expense.
Cavalry legions are gold pits, and much of a territory's tax revenue is consumed here.
Precisely because of this, the number of cavalry under one's command becomes the standard to judge a lord's strength.
Even with Black Stone Mine as a money-spinner, forming an Elite Knight Order is quite a challenge.
"If that's the case, I do have an idea." Sunan's eyes glinted slightly.
"What idea?"
Kei's eyes lit up, eagerly asking.
Having witnessed many of Sunan's miraculous methods, his trust in his brother was profound.
Upon hearing Sunan mention he has a way, Kei felt a surge of hope.
"Black Rock Leopard," Sunan said succinctly.
Kei immediately understood, his eyes sparkling.
He had seen the combat power of the Black Rock Leopard before, comparable to knights.
The key is, such puppet constructions fear no death, don't tire, don't need feeding; if used as mounts, they'd be the best!
"Can you refine Black Rock Leopard?" Kei looked at Sunan with hopeful eyes.
"Shouldn't be a problem," Sunan replied.
Thanks to the effects of the Active Potion, puppet refining studies have progressed rapidly, now over 90% complete.
In four or five days at most, he'll master this skill.
Then, he'll be able to refine Black Rock Leopards.
"Wonderful!"
Kei was ecstatic, instinctively standing, pacing excitedly, at a loss for words.
A cavalry legion with Black Rock Leopards as mounts would be the mightiest in Golden Rock Province.
With control over such a legion, even only at three hundred strong, Kei would have the confidence to counter-attack Flash City!
In his excitement, Kei looked at Sunan, internally filled with admiration.
After returning from the mine, he had received enlightening books from Sunan, intending to test himself for Wizard Apprentice potential.
But after reading a few pages, his head hurt like it was going to explode, forcing him to abandon the idea.
As it turned out, he lacked the aptitude to become a Wizard Apprentice.
He lamented this for several days.
However, he eventually came to terms with it; not becoming a Wizard Apprentice was okay, as long as Sunan was there.
With Sunan's support, the brothers would surely revive the Yanest Clan.
After a while, Kei calmed his inner excitement, firmly patting Sunan's shoulder.
"This matter is in your hands. If it succeeds, you will be our family's great hero!"
Sunan only gave a faint smile in response, steering the topic to the purpose of his visit.
Upon hearing this, Kei slapped his forehead, laughing, "I was just about to bring this up."
He got up from the desk, gesturing for Sunan to follow.
"Some time ago, I hired Thorn Flower Duchy's Fire Fox Trading Guild to help find what you needed. They just arrived in Black Stone City this morning and should be resting in the tavern now; let's go have a look."