Simulation: Starting from Under One Person

With that, Fang Rui turned and left, informing the main body of the countermeasures of a certain country.

………………

The Biyou, soaring through the sky, sails above the sea of ​​clouds, followed by several small flying boats.

From a distance, it looks like a luxurious ship on a journey, accompanied by a number of escort vessels.

The first floor of the Biyou is the residential area, where a cluster of grotto-heavens are neatly arranged. Fang Rui's residence is in Grotto-Heaven Number One...

The steep mountain peak, resembling a rock spear, is nestled halfway up the mountain, where an exquisite ancient-style manor is situated.

In the courtyard with its artificial hills and flowing water, there is an area for enjoying the scenery. The rattan table and chairs blend in with the surrounding environment without appearing out of place.

Fang Rui sat in a rattan chair, holding a drawing board in his left hand and a pen in his right. On the drawing paper was a monster in the style of Cthulhu, with numerical values ​​marked on some of its body parts.

"Ok?"

Fang Rui, who was deep in thought, suddenly raised his head, a hint of surprise flashing in his eyes.

"Did I give any orders to launch a beast horde attack on a certain American country?"

The slightest doubt vanished in an instant; it was nothing important anyway, so there was no need to worry about it.

However, he was somewhat concerned about the extremely efficient response of a certain country, as if it had been preparing for a long time and was just waiting for him to arrive.

"It's certainly possible."

Now that we know about the spiritual energy resurgence, isn't it normal to have corresponding countermeasures?!

"Interesting. Since you're prepared, then being a little more unrestrained shouldn't be a problem... right?"

Thinking this, Fang Rui's gaze fell on the final boss of this event depicted on the drawing paper. He felt that they should create some elite bosses to make the event more interesting...

Send a message to the clones, instructing them to continue creating all sorts of extraordinary creatures.

The clones who received the message: Huh?! It's not an interrogation! It's a new mission!

The clones, quite surprised, began their work with great enthusiasm.

They are always passionate about causing trouble.

Fang Rui himself was pondering what materials to use to create a certain BOSS; ordinary materials were definitely not a good fit.

If the materials used are too ordinary, the resulting boss won't be very strong. At the very least, the created boss should be able to fight back when encountering modern weapons...

After thinking it over for a while, Fang Rui had an idea. He sent Xu San a text message to inform the "company" of certain information, and then left the place.

Upon receiving the message, Xu San relayed it to Zhao Fangxu without hesitation.

"A very special sea monster..."

Upon receiving the message, Zhao Fangxu remained silent for a moment, then stared intently at the computer screen, which displayed the arrival and destruction of the sea monsters...

After all, such a big thing is impossible to hide, so the country has no intention of blocking the news and will not miss the opportunity to demonstrate its military power.

As for information involving core information, it will be removed.

Ignoring the useless or embellished text in the news, you can glean some useful information just by looking at the pictures, such as...

Some sea monsters are extremely large...

Generally speaking, the appearance of sea monsters is very random, with a Cthulhu-esque style.

And there are a lot of them...

The ocean is vast, and no one knows how many creatures live in it...

Similarly, the number of monsters in the ocean is also unknown.

"Order a batch of mechanical dolls, with surveillance capabilities," Zhao Fangxu said after a moment's thought.

Compared to sending people to guard the coastal areas, it is more convenient to deploy some artificial intelligence figures to monitor the coastal areas, although it is a bit more expensive.

"Understood," Xu San replied.

After the communication ended, Zhao Fangxu continued searching for news related to ocean monsters online, while Xu San boarded the airship and headed to the Biyou.

Since the Biyou is constantly in motion, you need to contact it in advance to confirm its route if you want to go there.

………………

At the same time, Fang Rui had already arrived in the other world.

"...Let's go check out Sagiri Mountain first!"

He was quite curious about what his clone had accomplished while he was away.

Mount Sagiri, as the former Water Pillar's residence, is a relatively safe area because the former Water Pillar, Sakonji Urokodaki, frequently patrols the area and kills any demons he finds.

After Fang Rui's clone moved here, the security level was further improved.

In the world of Demon Slayer, what demon could possibly be so arrogant in front of Fang Rui, Yoriichi Tsugikuni, and Tanjuro Kamado?!

How about an instant kill?

After learning just how powerful the three were, Kagaya Ubuyashiki moved to Mount Sagiri, and he came with them...

Aside from family members, there is the Demon Slayer Corps' support unit, "Kakuna," and the Butterfly Mansion that manages "Kakuna."

As for the swordsmith village...

For various reasons, the relocation has not yet begun, but the craftsmen have no objection to moving to Xiaowu Mountain. After all, Fang Rui had demonstrated superb forging skills, and many craftsmen wanted to learn from him.

After a period of development, the area around Mount Sagiri has become very prosperous and bustling.

Some ordinary people, unaware of the truth, saw so many people gathered here and decided to settle down here.

With three trump cards in hand, Kagaya Ubuyashiki changed his mind and decided to reveal himself openly in an attempt to attract the demon king.

Perhaps it was because the news traveled slowly, or perhaps it was because the demon king was cowardly, but the town had never been attacked by demons.

"It's so lively!"

Above Mount Sagiri, Fang Rui looked down at the prosperous town with some surprise.

How long has he been gone? There's already a small town here.

Could it be more than ten years?

Has Muzan already been taken out to sunbathe?

With that thought in mind, Fang Rui teleported to the Narrow Mist Mountain, next to an ordinary house.

Directly in front of the house is an open space with round tables and stools carved from pure wood, a simple swing, and an ordinary seesaw...

Two men sat around a round table, dressed in similar clothes, with similar hairstyles and hair color, and wearing identical earrings, calmly playing chess...

The other play areas were filled with children.

'Where did this little kid come from?'

The doubt vanished in an instant, as Yoriichi Tsugikuni and Tanjuro Kamado had already sensed Fang Rui's presence and looked over.

The two had very keen senses. Although they could not see through Fang Rui's true strength, they could vaguely sense his strength and weakness.

Therefore, when Fang Rui left, the two noticed the change in "Fang Rui," after all, the difference in strength was quite large.

Upon seeing the other Fang Rui, the two men immediately showed expressions of realization.

"You're back~"

Fang Rui heard a different meaning in the ordinary words and tone.

"When did you find out?" Sitting opposite the two, Fang Rui's lips curled into a slight smile.

“At first,” Yoriichi Tsugikuni replied, “the changes in the strength of the aura were too obvious.”

“Is that so…” Fang Rui nodded slightly. “This can be considered one of the methods to distinguish him from his clone.”

Later, he said, "Tell me what happened after I left..."

Tanjuro Kamado begins his story...

With the support of Fang Rui's clones, the Demon Slayer Corps acquired some new weapons...

After trial use, it received unanimous praise.

Kagaya Ubuyashiki and others have come to ask several times whether mass production is possible.

Because the forging of the new weapons involves some of the techniques of weapon refining, mass production is out of the question.

The most personalized customization.

"Tell me in detail."

Fang Rui showed great interest in the work featuring clones.

"The new uniforms of the Demon Slayer Corps' pillars are made by melting down crimson sand iron and crimson ore, then turning it into soft silk, and finally combining it with other materials to create special clothing. When a demon touches this clothing, it will feel like being cut by a Nichirin Blade, causing burning damage to the demon..."

"The new Nichirin Blade resonates with the Breathing Technique, causing wind, fire, lightning, rock, and water to swirl around its blade, dealing elemental damage. However, maintaining it requires a lot of stamina, and currently only a few swordsmen can use it for extended periods..."

"Flashbang, made primarily of crimson ore and crimson iron sand, is a disposable item that detonates the sunlight energy stored within the ore, causing damage to demons within a certain range..."

Listening to Tanjuro Kamado's story, Fang Rui nodded slightly, thinking to himself: It sounds pretty ordinary! Isn't there anyone more impressive?

Or……

Wow, you didn't even use it?!

Thinking this, Fang Rui turned his gaze to the house. He sensed that his clone wasn't inside; he wondered where it had gone to play.

After speaking with the two, Fang Rui got up and left, heading to the workshop of his clone.

The room used for storing items was filled with all sorts of metal artifacts: swords, spears, halberds, axes, and other weapons, as well as armor resembling that seen in some games...

"They're all magical artifacts!"

As he said this, Fang Rui was somewhat disappointed.

There isn't a single magical artifact. Is it due to material limitations?

"But the quality is quite good."

Fang Rui glanced at all the magical artifacts and nodded slightly.

After finishing his evaluation, he turned and left the room, sending a message to his clone using a telepathic spell, telling him to come back quickly and that he had something to ask him.

After that, he sat at the solid wood round table and played Go with Yoriichi Tsugikuni and Tanjuro Kamado, occasionally offering some bad advice...