Zaydas' territory in the Underworld is near Lilith.
The first thing Zaydas did was surround the entire land with high stone walls.
It wasn't difficult; after all, although it wasn't rich in resources, it had some stone mountains that he used.
And the important thing wasn't the fortress itself but rather the division of the territory. He wanted to have a clear separation between his territory and the rest.
He created a total of four entrances to his territory.
After all that was done, he strengthened the time flow change in his territory to 1/100, spending 100 AP to maintain it for 5 hours outside and 500 hours inside his territory.
Only Grayfia was accompanying him at that moment.
Zaydas' move to build the wall around his territory and also change the time flow went unnoticed until a few minutes passed and the hidden things became apparent. When an hour had passed, what was supposed to be a desolate area had turned into a developing city.
Zaydas' parents were not present in person, but they saw everything through a live recording.
"Zay is becoming more and more unfathomable," Sirzechs said with a proud smile.
That was his son… Theirs. And seeing his growth—how could they not be satisfied with it?
"It seems it won't be long before he reaches us in terms of power, perhaps even surpasses us," Zatanna said with a loving gaze.
If she were talking about any other man, whether by tone or look, Sirzechs would turn green with jealousy, but since it was their son, he simply smiled and agreed.
Until then, Zaydas hadn't conquered anything. But at the same time, he had conquered many things. His achievements in the Underworld were not yet clear, but the moment he participated in any significant event, others would understand who their son was and what kind of genius he was.
"When he becomes stronger, I plan to take him to my home universe. Is that okay?" Zatanna asked.
"Yes, do as you wish," Sirzechs added. "But I also want to be present."
Resting her head on his shoulder, she nodded.
As for making the Phoenix Clan the main wife of their son—sorry, but that won't happen. Now that the two of them understood each other, even Grayfia was expecting a child from Zaydas… How could they not favor her? Of course, that wasn't the only reason. If they were to list all the reasons to favor Grayfia, the list would be long.
───────────
In his territory, Zaydas spent another 86 AP and continued with the time flow at 1/100.
Then, he began to expand, growing into a 150-meter-tall giant.
With that done, building the city became much easier. It was as if he were creating a model, and with a simple wave of his hand, using Modeling, he constructed several streets. Another wave of his hand, and he built buildings.
Grayfia, watching all of this, was left with her mouth wide open.
'As I thought, he hides his abilities well...' The more she discovered about him, the more surprised she became. Not that size-altering abilities were something she had never seen before, but the way Zaydas did it—casually expanding as if he were just shaping his territory—made it unbelievable.
Not to mention that he grew to 150 meters tall. That was even larger than several legendary creatures.
Another incredible thing was the clothes he wore, which expanded along with him without tearing.
Meanwhile, Zaydas was constructing a giant castle, fit for royalty.
Not that he cared much about such luxuries, but since he had a large family—and intended for it to grow—a conventional mansion wouldn't suffice; only a castle would be appropriate.
In addition to conventional materials, even Magystones were used, which he had taken from the sealed cave.
Even small pieces of Magystones gave the castle a magical effect. Of course, that wasn't all. There were Magicula pillars that served as structural supports for the castle, as well as magical cores that functioned in specific parts of the castle, making the energy within more dense.
Although it wasn't exactly like a cultivation world, simply being in a room with monster magic cores was enough to strengthen someone with every breath. Even if just slightly, it was still an improvement.
Another feature was that when someone approached the Magicula pillars, they would glow, illuminating the castle's corridors—a true fairytale magical castle.
Even Grayfia was enchanted by the sight of such a castle.
Like a typical castle, there were multiple pointed towers, each essentially a different section of the structure. The tallest tower at the top housed the main suite.
Afterward, he created formations and commands using [Program]. The commands were simple for now, nothing too creative to avoid taking up too much time. However, once he returned to his original size, he planned to create clones that would use [Program] to make the castle appear even more magical than it already was.
Wouldn't it be interesting to create commands for paintings to talk just like in Harry Potter?
Putting that aside for now, after the castle was ready, Zaydas began constructing areas such as orchards, huge pits that he would later use for fish, nurseries, etc.
All this time, Grayfia kept watching. She had the option to enter the castle, choose a room, and sleep, but she enjoyed seeing him work with such a focused expression.
Of course, she didn't just stand there observing. Bringing a table and chair, she created a campfire and made tea for herself.
By the way, Grayfia was already considered incredibly beautiful. However, with smoky makeup, she was breathtaking. The simple flutter of her lashes as she closed her eyes was incredibly charming.
She looked even more stunning as she calmly sipped her tea, resting her chin on her hand, gazing at Zaydas lovingly.
This sight did not go unnoticed by Zaydas.
For a moment, he was stunned and felt a deep sense of fulfillment. For a moment, he wanted to stop everything and go to her, but he managed to restrain himself.
───────────
Two girls wearing white overcoats arrived in Japan.
One was a beautiful young woman with violet eyes and long brown hair tied into twin-tails, each secured with a blue hairband. The other was a beautiful young woman with chin-length blue hair, with a green-dyed fringe on the right side, and brown eyes.
Whether because of their appearance or the way they dressed, they attracted attention wherever they went.
"Irina. Are you sure it's this way?" the blue-haired girl asked.
"Xenovia, how many times do I have to say this?" Irina replied. "I lived here, even if it was when I was little, of course I'm sure~!"
"But I still have to say," Xenovia looked around. "This country is a bit strange. I can barely feel their faith."
Frowning, Irina then said cheerfully, "It's simply because you can't feel it, but that doesn't mean it doesn't exist~ Anyway, let's go~!"
"Yes, yes." Agreeing, Xenovia quickened her pace. Soon, she muttered under her breath, "But I really don't want to talk to any Devils. If it weren't for the fact that we have to operate in a city controlled by Devils, I would just cut them down with my sword."
"Don't say that. Despite everything, we're talking about the sister and son of the Maou," Irina warned, turning serious. It was rare for her to be this serious. This showed how much importance they placed on the fact that they were related to the Maou.
"What's so special about that?" Xenovia was fearless.
Her confidence came from the belief that the side of "good" always wins and is always right. She strongly believed that if something happened, they would be victorious.