Although the Sea of Demons is the core of the Underworld, it was sealed off because it was difficult to utilize and dangerous.
Especially since it contained dangerous creatures from the ancient Underworld.
Lacking intelligence and unable to adapt to the environment outside of Hell, they naturally couldn't serve as familiars, nor could they be put to use.
Even as "materials," they were unusable due to their pollutive nature.
Building a city here was as laughably suicidal as it could get.
Despite this, the Sea of Demons remained an extremely special place. To take over this territory, Sirzechs made many compromises.
And those guys in the Devil Council, thinking they had bled Sirzechs dry, were cheering for joy, but they would have plenty to regret in the future.
"Um, are you sure a city can be built here?"
Aizen, Kisuke Urahara, and even everyone else had strange expressions on their faces.
Rias and Sona, along with those brought from the "Shinigami" world, were Rias's foundation.
Not in terms of their strength, but their prestige.
However, if one were to speak of it, none of them were weak.
Together, they formed a force that even the Devil Council could not ignore.
Coupled with the help of Sirzechs and Serafall, they could manage even if they needed a territory with a special status like the Sea of Demons.
"Fufu, do you want me to freeze this Sea of Demons?"
Serafall suggested.
"That won't work."
Rias shook her head and said, "As the core of the Underworld, the Sea of Demons has extremely powerful Water Veins. Combined with its high corrosiveness, even ten-thousand-year-old ice wouldn't last long before being assimilated."
"Who would dare to come to such a dangerous city?"
"Hmm, then what should we do? I can't figure it out at all," Serafall said with a bit of a headache.
"I'm curious too."
Sirzechs also spoke.
Because of Rias's invitation, and since this was indeed no small matter, Sirzechs brought his peerage along to this dangerous sea area.
If there was a need, they could even help out a little.
It was clear, however, that while Rias appreciated the gesture, she didn't need the help.
Because it wasn't necessary.
"It's very simple."
Rias smiled and said, "The city, in fact, has already been completed."
"Completed?"
Everyone said in surprise.
Several people looked around but couldn't see the city Rias mentioned.
"Then, take a good look."
Rias let out a light laugh and took out magical devices from her storage space.
The number of these magical devices totaled one hundred thousand!!
Countless magical devices flew toward the Sea of Demons. Surging black mud and sulfuric acid spread everywhere, and a pungent smell could be detected in the surrounding air.
This smell was hard even for devils to endure; if a human were to come here, they would likely die before long.
Amidst the extremely harsh environment, countless magical devices shuttled back and forth.
After entering their fixed positions, a total of seven special magical devices first revealed themselves.
The seven special magical devices unfolded, forming the points of a heptagram. Red magic circles connected the ocean and the sky, and a massive magic circle expanded.
At the same time the heptagram lit up, the center of it also slowly began to glow.
"Pride, Envy, Wrath, Sloth, Greed, Gluttony, Lust—"
Rias murmured softly, saying, "And the Demon God as the core—"
"With the Demon God as the core and the Seven Deadly Sins as the source of Power."
"Absorbing the Water Veins and Heavenly Veins as the Power source."
Rias said softly, "Deploy, Castlevania!"
As her words fell, instantly, all one hundred thousand magical devices emitted a dazzling light.
In an instant, a massive city appeared above the Sea of Demons.
There were seven statues in the seven corners, and the core position was the mansion symbolizing the lord's residence, which was the true heart of this city.
Like a city from a Fantasy, it propped up a deep blue castle.
Although it was called Castlevania, it didn't have the slightest sense of devilish gloom; instead, it was filled with a refreshing feeling.
The ocean boiled continuously, providing Power for this massive city.
The violent Power within the Water Veins was tamed, providing energy for the city.
The filthy ocean's Power was continuously absorbed, and what remained was the purest water source, becoming part of the city's beauty.
The city area alone was 500,000 square kilometers; it was initially estimated that a population of over a hundred million would have no problem living there.
Resources such as materials and food could even be automatically generated by the city.
The city and the Sea of Demons cycled automatically, purifying the Sea of Demons in the process, turning the most dangerous area in the world into a habitat for devils.
"This... this is..."
Everyone was speechless.
Even Aizen, Kisuke Urahara, and Sirzechs were shocked.
create and destruction are two completely different concepts.
Creating such a massive city already belonged to the realm of gods.
At this moment, Sirzechs even wondered if Rias's identity before reincarnation was that supreme god in the Biblical Pantheon. The God of the Bible.
The God of the Bible.
It was too exaggerated, so exaggerated it was beyond imagination.
And now, a myth was right before their eyes?
Yes, even for them, as mythical beings, this was a scene worthy of being called a "myth."
This was a realm similar to, yet different from, that of the God of the Bible.
Not just in destruction, but Rias had also made great progress in the aspect of create.
And this was only after two years.
"The basic core is very stable; even if small problems arise in other areas, it won't matter."
Rias sensed the basic condition of the city and then murmured.
This city was completely under Rias's control, everything, even a single brick.
Before constructing her "Power," this city was Rias's grandest work.
It was also Rias's current limit.
To surpass this limit, she would either need to put in long-term effort or... acquire new elements.
"Little sister..."
Sirzechs said blankly, "This thing... did you create it all by yourself?"
"Well... I had a few assistants."
Rias smiled.
Despite saying that, the others in the group were at most just assistants.
Everything—the city's structure, design, requirements, and so on—was set by Rias herself.
And the production of the magical devices was also completed by Rias herself.
All one hundred thousand magical devices combined to form this city.
After the magical devices were deployed, the cores had completely fused together.
In other words, this was already a permanent "Shikai."
"It's too exaggerated..."
Serafall couldn't help but gasp.
Meanwhile, Aizen and Kisuke Urahara were both thinking: could the "Soul King" achieve something to this extent?
The answer was obvious—no!
This was not a god's authority, but something composed of countless magical devices, through the Power of a mere "person."
And it was the Power of one person!
"Marveling at the city can come later."
Rias looked at Sirzechs and gave a meaningful smile, saying, "Brother, could you use your influence as a 'Devil King' to help me with some promotion?"
---------------------------------
I hope you're enjoying the fanfiction so far! If the story has you hooked and you can't wait to see what happens next, you can unlock 30 chapters in advance over on my Patreon: patreon.com/TLHimejima1
Every bit of support means the world to me so if you're loving the ride, don't forget to drop a Power Stone and let me know.