As Li Ji recounted, the more he spoke, the more solemn Wu Tao's expression became.
This region was far vaster than he had previously imagined.
The giant city they had seen earlier, named Tongguan City, was merely one of seventy-two such cities belonging to the human race, considered a human territory.
And Tongguan City alone, along with the people living in its surroundings, numbered over a billion.
Moreover, this region was not solely inhabited by humans; there were also the Yan, Xue, Gui, Yun, Bing, She, Ling, Zhan, Wu, Shu, Niutou, Goutou, Huangjin, and over a hundred other powerful races, no less significant than humans.
Due to the unique survival environment of the underground world, cultivators and mortals alike had to concentrate all their strength within cities to survive.
...
Although the survival environment here was somewhat harsh, the resources required for cultivation were abundant, not lacking in any way.
The City Lord of Tongguan City was a great cultivator in the late Nascent Soul stage, named Xie.
Beneath the City Lord were four Deputy City Lords, all cultivators in the mid-Nascent Soul stage. In addition to these five main and deputy lords, there were over a dozen other Grand Elders in the Nascent Soul stage.
Life within the center of Tongguan City was naturally much better than the constant threat of attacks from external races outside the city.
Mentioning this, Li Ji’s face was filled with evident envy.
...
After listening to Li Ji's narrative, Wu Tao's heart was in turmoil, yet his expression remained outwardly calm.
After a moment of contemplation, Wu Tao asked again, "Li Ji, are there frequent activities of itinerant cultivators in Tongguan City?"
"Yes, Senior."
Li Ji nodded quickly.
Wu Tao then inquired further, "Do you know the reason?"
"This..."
Li Ji hesitated and replied awkwardly, "Forgive me, Senior, I truly do not know."
This answer was not unexpected. Wu Tao shook his head; it seemed he would have to investigate Tongguan City himself.
...
Now that there were many itinerant cultivators coming and going, the possibility of his identity being exposed was significantly reduced. He might as well go and see for himself.
Just at this moment, a world-shattering explosion echoed.
Li Ji suddenly cried out in alarm and hurried out of the stone hall, muttering as he went, "Why is it happening so soon today? It shouldn't be at this time."
Wu Tao also frowned, walked out of the stone hall, and looked towards the sky.
A towering hundred-zhang giant peak stood silently amidst these villages, with wisps of black smoke continuously rising from its summit, as if it were about to erupt.
"A live volcano! There's a live volcano nearby..."
"Are these cultivators insane? Building villages here."
"Is there also a grand formation controlling this place?"
Boom!!
Another earth-shattering explosion sounded, and countless black smoke billowed up. The entire volcano seemed to come alive, roaring fiercely at the sky.
A massive column of black smoke shot directly into the sky, turning the heavens completely dark.
"No, why aren't there any lava flows?"
It was only then that Wu Tao suddenly realized, thinking to himself, "This must be the work of the cultivators within Tongguan City, right?"
At this moment, the mortals in the village were kneeling on the ground, shouting loudly, "The immortal masters have bestowed their blessings! Thanks to the great immortal masters."
Swoosh!
A light rain began to fall from the sky, countless black dust particles descending with the gentle breeze.
Black raindrops continuously fell onto the ground, staining it a dark gray.
Many children ran to the stone hall, knelt before Wu Tao and Li Ji, and respectfully kowtowed, saying in unison, "Thank you, Lord Immortal Master, for the blessings you have bestowed upon us..."
"Is this volcanic ash?"
Seeing this, Wu Tao curiously extended his right hand. With a surge of spiritual energy within him, he drew some black dust, holding it in his palm for a closer inspection.
"It seems to have some artificially added components. The minds of the cultivators in this place, tsk tsk, are truly remarkable!"
"Volcanic ash is naturally rich in nutrients, greatly beneficial for plant growth. Moreover, the cultivators have added some other substances to it."
...
"With these, the crops in the soil here can yield astonishing harvests every season."
"Senior is correct. The esteemed individuals of Tongguan City control the eruptions of dozens of live volcanoes of varying sizes nearby, and transport the resulting volcanic ash uniformly to the various villages to fertilize the land."
Having regained his senses, Li Ji bowed again and explained to Wu Tao.
"What terrifying power!"
Wu Tao muttered to himself, the formation and cultivation required to control such a large live volcano must be astonishing.
...
Furthermore, directly using a live volcano as a tool for fertilization, such ingenuity and boldness truly impressed Wu Tao.
However, if cultivators in the Kyushu cultivation world truly wished to achieve this, they could.
But cultivators in the Kyushu cultivation world would not put in such effort for ordinary people. Including Wu Tao, not a single cultivator would consider the quality of life of mortals as a significant concern.
...
This was because, although the mortal world was the rear support of the cultivation world, instability there would also affect the cultivation world.
However, with the human race dominating Kyushu and being invincible in all directions, cultivators in the Kyushu cultivation world only needed to manage them in a hands-off manner.
...
"That's right, I almost forgot. In this region, humans are not the sole overlords; there are other powerful races that can contend with humans."
"In that case, mortals are also a valuable resource for the cultivators here."
"Among the cultivators of this region, there should be some who are specifically responsible for dealing with natural disasters and climate, and perhaps even cultivators specializing in agriculture and increasing land yield."
"It is likely that the purpose of these cultivators going to such lengths is to increase the mortal population."
...
Wu Tao sighed. It appeared that the cultivators in this region did not value mortals that much.
Instead, due to the special environmental conditions, they were compelled to find ways to preserve the mortal population.
The only difference from the cultivators in the Kyushu cultivation world, who viewed mortals as ants and remained aloof, was the specific implementation methods due to differing circumstances.
It was akin to herding sheep. The reason why cultivators in the Kyushu continent adopted a crude feeding method was because the environment was suitable and posed no significant dangers, allowing mortals to grow and thrive without needing much attention.
...
Conversely, because of the harsh environment and numerous surrounding dangers, cultivators in this region had to painstakingly devise methods to protect the safety of these mortals.
Although the environments and methods differed, the ultimate goal in both cases was to obtain the resources they needed from mortals!
...
"Village Chief!"
Just then, a rough voice, though clearly suppressed, echoed from outside the door.
"Why are you still standing outside? Hurry and bring it in!"
Li Ji called out upon hearing the voice, then stepped forward and bowed, saying, "Senior, I have ordered some food to be prepared. It's a small place, and we don't have much to offer, but I hope Senior will not mind."
Wu Tao glanced towards the door and saw three or four people, each carrying a tray, walking in.
Seeing this, Wu Tao shook his head and, in the next instant, vanished from the spot.
Only Li Ji and the three or four individuals remained, looking bewildered.
Tongguan City, as its name suggests, is a place where mountains divide and rivers cut off, making it as impregnable as a fortress, where a single guard can prevent thousands of enemy troops from entering.
While others build mountains from mounds of earth on plains, the mad cultivators who originally constructed Tongguan City directly carved open a mountain range.
Then, relying on the mountainous terrain, they hollowed out the mountain bodies to build it, layer upon layer, with the mountain and city seamlessly integrated.
This was a colossal city built over countless years and generations, capable of housing a population of one hundred million.
"What a grand undertaking!"
Wu Tao couldn't help but praise it inwardly.
The cultivators who undertook such a massive project at the time certainly weren't doing it out of idleness.
This was evident from the mottled city walls.
The city walls, resembling mountain bodies, were constructed from massive iron stones, each thousands of meters in size.
These iron stones, having endured the passage of time, wind, rain, snow, and bloodshed from wars, had long lost their original color.
Each piece was a dark iron-blue, resembling pieces of rusted iron that had been weathered by wind and rain.
The surface of the city walls was pitted and scarred, bearing countless marks of knife cuts, axe blows, and beast claws, exuding an aura of profound vicissitude.
These scars on the city walls, far from making this colossal city appear dilapidated, instead lent it a sense of steadfastness.
...
If it were merely this, it would be acceptable!
However, the restrictive formations and runes that occasionally flickered on these city walls were even more awe-inspiring.
The cultivators guarding the city were all elites, their eyes sharp and filled with killing intent.
Wu Tao stood at the foot of the city, observing briefly, then quickly gathered his thoughts and turned his gaze towards the gaping city gate.
Beyond it, a large number of mortals were driving ox carts and horse-drawn carriages, forming an endless queue and slowly entering the city.
...
At this time, according to the clock, it should be midnight.
However, under the perpetual fiery river overhead, the entire Tongguan City was akin to a city that never slept, remaining as bright as daytime for twelve hours, thus having no significant impact.
These mortals coming and going were likely residents of the nearby villages, no different from the small village Wu Tao had just left.
In Wu Tao's observation, the closer a village was to Tongguan City, the better its inhabitants lived.