According to the construction standards for Immortal Cities, the baseline population capacity of each city was two million. The minimum viable number was around 300,000 to 500,000 to maintain basic functions. Typically, cities operated at around 1.2 million residents, and 2 million was considered the upper limit.
Exceeding this number would strain city systems—food supply, transportation, and daily life would all be negatively impacted.
For city officials, more people meant exponentially increased management difficulty, a higher risk of chaos and crime, and a greater challenge to maintain order. Still, this was a test of their governance. If they could withstand the pressure, their capabilities would be proven—and open the way to future promotion.
But the 1.1 trillion citizens registered were not the full extent of Great Yi's true population.
Yi Tianxing's Hongmeng Heavenly Emperor Pagoda (鸿蒙天帝塔) still held a vast reserve of battle-ready troops, male and female alike. Although the War against Eternal Night had claimed many lives, the number of new recruits acquired afterward was even greater—staggeringly so.
Yi estimated the total hidden population to be over 100 trillion. Thankfully, they remained sealed within the tower or placed in time-stopped stasis using the Chrono Pocketwatch, awaiting revival. Had they been released, the sheer pressure on Great Yi's infrastructure would have been unimaginable.
Thus, from a population base alone, Great Yi was more than ready for massive expansion.
But first, they had to relieve the current population pressure.
In theory, the solution could be to release the excess population into the wilderness and rapidly build new cities. However, that would contradict the original principle behind the layout of the Immortal Cities:
Each Immortal City was built to suppress a 1000-li radius of wilderness.
That wasn't just a military decision—it held strategic and metaphysical importance. The wilderness mattered too.
"How goes the project I assigned to the Ministry of Works back then?"Yi Tianxing asked, turning his gaze toward Minister Pei Ju.
Pei Ju stepped forward respectfully:
"Following Your Majesty's command, the Ministry of Works and Heavenly Works Pavilion (天工阁) collaborated to build Immortal Cities at scale.In the first year, we completed 300 cities, averaging more than one per day.In the second year, with more labor available, 400 cities were built.In the third year, that number rose to 600.As of now, we have completed over 20,000 Immortal Cities, ready for immediate deployment."
Twenty thousand cities sounded impressive, but even if each housed 500,000, that only supported about 1 trillion people—barely scratching the surface of Great Yi's needs, especially when considering the hidden reserves of soldiers in the Hongmeng Heavenly Emperor Pagoda.
In short, it was a drop in the ocean.
"Not enough," Yi Tianxing said flatly."The number of cities is far too low for our rate of population growth.Ministers, do you have any solutions?"
Gongshu Lin, Head of the Heavenly Works Pavilion, stepped forward confidently:
"It's not a manpower issue—but a bottleneck in materials.Specifically, the production of Xuanhuang bricks (玄黄砖) via the Heavenfire Furnace has been too slow.However, since integrating the furnace into the Cloud Realm, we can now produce sub-furnaces.With over a hundred sub-furnaces operating at once, and sufficient bricks, we can easily construct ten to a hundred cities per day."
His confidence was unshakable.
Previously, progress was constrained by brick output. But now, the Heavenfire Furnace—powered by all known divine flames—could operate at unimaginable efficiency. The sub-furnaces were almost as powerful as the original.
Notably, many citizens had taken up a new profession: City Architects.
However, it wasn't just labor. City construction was a highly technical field, requiring knowledge of formation inscriptions, feng shui, urban planning, and basic infrastructure layout. Every city had to be fully functional upon completion—ready for habitation.
And Great Yi had made astounding progress in this area.
Over the past twenty years, they had begun integrating spatial techniques into architecture.
One house, from the outside, looked ordinary. But inside, using the Mustard Seed Contains Mount Sumeru technique (芥子纳须弥), it opened into a space ten, even a hundred times larger.
This innovation was called the Dimensional Construction Method (乾坤构造法).
The goal: maximize space while maintaining quality of life.
Each residence had its own Dimensional Dwelling (乾坤洞府), which could be accessed or exited via the resident's Celestial Identity Card. This card served as both key and anchor—making movement seamless.
Inside the dwelling, residents still experienced the scenery, day-night cycle, and stars of their actual Immortal City. To the people, this innovation felt like the city itself had expanded.
Without this breakthrough, Great Yi could never have housed its exploding population.
Currently, many talents were dedicated to improving this dimensional architecture, aiming to expand its internal space further.
Dimensional Dwellings came in three sizes:
3-li radius
5-li radius
10-li radius
Even 10-li was currently near the upper technical limit.
Under imperial guidelines, a 3-li space housed 100 families. Even with three generations under one roof, the space was more than enough. It could comfortably support tens of thousands.
Thus, every Immortal City now needed engineered residential districts with integrated Dimensional Dwellings.
Yi Tianxing nodded in approval:
"Very good. City construction must proceed without delay.We cannot allow our infrastructure to fall behind."
Figures like Zhuge Liang, Yang Ye, and other generals listened closely.
They all knew: now that they had returned to the Eternal World, expansion was inevitable—and on an enormous scale.The military would be at the forefront—but they feared only one thing:
Logistics failing to keep up.
To the military, logistics meant cities. If there weren't enough cities, they couldn't stabilize the territory they conquered.
With Heavenly Works Pavilion and the Ministry of Works committed, the generals were visibly reassured.
"By the way," Yi Tianxing asked,"Who invented the Dimensional Dwelling? I'd like to hear the full story."
Though its benefits were clear, he wanted to understand its origins.
Gongshu Lin answered proudly:
"The technique was proposed by a gifted craftsman named Hu Zeyang, a member of the Heavenly Works Pavilion.He noticed the growing space crisis in our cities and wondered if the Mustard Seed technique could be applied to every home.With help from our craftsmen and scholars from the Immortal Academy, they overcame countless obstacles and created the Dimensional Dwelling Method."
"Currently, the dwellings are residential only—they can't grow plants or raise animals.But we're working on that.Led by Hu Zeyang, a team is researching how to make these true blessed lands (洞天福地)—complete with gardens, medicinal fields, and crop space."
Hu Zeyang was no ordinary person.
He was a survivor from a modern civilization, formerly a designer and architect. A brilliant mind with unconventional ideas, unbound by tradition, with boundless imagination.
Yi Tianxing was impressed.
"So not all talent must come from history.Those overlooked in the past now rise in this age of upheaval.In Great Yi, if you have ability—you'll have the chance to shine."
And the Dimensional Dwelling, make no mistake, was not something that just anyone could create.