In just a single day, Teach returned to the Battle Pyramid, a speed that finally allowed Redyat and Mostima to breathe easy. During his brief absence, nothing unexpected had occurred, and the entire operation continued smoothly under their control.
Neither of them asked where Teach had gone.
Still, they could both sense it. Something about him had changed. His presence felt lighter, almost… satisfied, as if a long-standing weight had been lifted.
They did not press further. Instead, they brought him news.
Good news.
And it came from the Kingdom of Christi.
With the immense funding poured in by the Nightfall Pirates, combined with scientists recruited from across the world, cutting-edge research equipment, and a steadily growing technological base, their efforts had finally begun to bear fruit.
Whether it was the underground research facility beneath the Kingdom of Christi, or the hidden sky island base floating twelve thousand meters above it, both had achieved initial breakthroughs during the year since the Nightfall Pirates seized control of the Sageros Sea.
The investment had proven entirely worthwhile.
Although Otto's central control system had not yet reached completion, a preliminary framework had already been constructed. It was still far from the level Teach envisioned, but the foundation existed. From here, it only required continued iteration, refinement, and expansion.
At present, the system could only control a limited number of "life machines," and its operational range was restricted to the Kingdom of Christi itself. Expanding its reach to cover the entire Sageros Sea remained a significant challenge.
Even so, the most difficult first step had already been taken.
From this point forward, progress would accelerate.
At the same time, two types of mechanical units had successfully entered production.
Mechanical dogs and mechanical birds.
Assembly lines had been established, and both were now being manufactured continuously.
Mechanical dogs possessed strong offensive and defensive capabilities. While they could not compare to the Pacifista models of the future, a single unit was more than capable of dealing with an ordinary pirate with a bounty of five million Berries.
Of course, the current models were still crude.
Future upgrades would integrate enhanced weapon systems, with the goal of allowing a single mechanical dog to contend with pirates worth ten to twenty million Berries. That projection carried some exaggeration, as their intelligence remained basic and exploitable, but that had never been their intended role.
From the very beginning, the Nightfall Pirates designed them for group combat.
A swarm.
When deployed in numbers, even pirates with bounties exceeding one hundred million would find themselves overwhelmed.
And most importantly, their production cost remained low.
They were, quite literally, the claws and fangs of the Nightfall Pirates.
Mechanical birds, on the other hand, served a different purpose.
They were aerial weapons.
Capable of high-altitude flight, they could drop explosive shells, poison gas, and other payloads from above. Each unit also carried an internal self-destruct mechanism, with destructive power far beyond its size.
Yet their greatest value lay not in destruction, but in surveillance.
Every mechanical bird functioned as an eye.
Through visual transmission, everything they saw could be relayed back to the central system, enabling real-time monitoring across the territory. In effect, they formed a technological equivalent to the Homies of the Big Mom Pirates.
One born from Devil Fruit power.
The other from science.
Each had its strengths and weaknesses.
The Nightfall Pirates bore greater upfront costs, but their creations could be repaired and reused. Homies, once destroyed, were gone permanently, and creating new ones required sacrificing lifespan.
For Charlotte Linlin, lifespan was a resource she could harvest in abundance.
For Teach, efficiency and scalability mattered more.
Though mechanical units lacked the higher intelligence of Homies, their connection to the central system ensured instantaneous coordination, something even living creations could not match.
As research continued, Otto's own abilities developed rapidly.
The Weapon-Weapon Fruit was evolving alongside the technology it supported, accelerating the pace of innovation. If it ever reached awakening, Otto would gain the capacity to create massive war constructs directly through his ability, something akin to an Ancient Weapon.
For now, however, such creations remained hidden.
With forces from across the world gathered in their territory, revealing these assets prematurely would be reckless.
At present, only the Night Palace showed signs of these developments. Black mechanical hounds and falcons patrolled its halls, their bodies covered in artificial skin that gave them an eerily lifelike appearance.
They moved with purpose.
They watched everything.
And though their intelligence was still rudimentary, their connection to the central system made them far more dangerous than they appeared.
This was still an experimental phase. Once the technology matured, all current models would be recalled and rebuilt from the ground up.
For Teach, this progress came at exactly the right time.
The Sageros Sea remained unstable, and true control required more than just overwhelming strength. According to Otto's projections, it would take three to four more years for the central system to reach full operational capacity.
The difficulty of its development had exceeded expectations.
Each upgrade would multiply its coverage range, but also increase the complexity of the system exponentially.
Even so, this timeline was acceptable. Teach could afford to wait.
There were other ambitions as well.
The moon.
Teach had not abandoned the idea. The ancient ruins there contained advanced artificial intelligence and autonomous robotic systems far beyond what currently existed in the world.
But for now, leaving was impossible.
The Goro Goro no Mi and the Plasma Fruit still lacked suitable users, and neither had been developed to the level required to power the massive Ark Maxim.
The version Teach envisioned dwarfed the one once created by Enel. Its scale alone demanded an enormous and stable energy source.
Which brought him to another line of research.
Seastone.
This mineral contained a unique form of energy tied to the sea itself. If harnessed correctly, it could potentially replace conventional power sources and serve as the core energy system for the Ark.
Unfortunately, such research was extraordinarily complex.
Teach had already prepared himself for a timeline exceeding a decade.
At times, he even considered leaking partial information to the World Government, allowing them to advance the research before seizing the results for himself. It carried risks, but the potential gains were too significant to ignore.
After all, Wano Country controlled the raw material, but lacked the industrial base to utilize it fully.
In the end, the greatest beneficiary would still be him.
Meanwhile, the blueprints for Pluton had already been fully analyzed.
As expected of one of the Ancient Weapons, its design was extraordinary. However, the cost of constructing such a warship was immense, and its practicality did not align with the Nightfall Pirates' current priorities.
Instead, its weapon systems would be studied and adapted into more efficient technologies.
Alongside this, the research data left behind by Vegapunk on Karakuri Island remained preserved, waiting to be fully understood. Once unlocked, it would provide an enormous boost to their technological capabilities.
The world was changing.
Science had become the driving force of progress.
Even if it could not yet rival top-tier combat power, its dominance in large-scale warfare was undeniable.
Teach had no intention of falling behind.
While Otto's domain focused on machinery and systems, the sky island base pursued a different path.
Biochemical research.
Their work centered on the Super Soldier Serum, human evolution, genetic engineering, and biological modification. These were dangerous fields, bordering on forbidden knowledge, and some experiments inevitably crossed moral boundaries.
But the rewards were equally great.
The Nightfall Pirates had already gathered a vast number of scientists from across the world. Some had joined willingly, drawn by the resources and freedom offered. Others had been taken by force, along with their families, ensuring their cooperation.
At first, resistance existed.
Over time, it faded.
Given unparalleled funding, unrestricted research conditions, and the promise of breakthroughs that could reshape the world, even the most reluctant minds eventually immersed themselves fully.
Time erased hesitation.
And ambition did the rest.
The Super Soldier Serum had already produced its first result.
A semi-finished product.
It achieved only about one-third of the effectiveness described in the original data, largely due to differences in materials and environmental factors. Even so, the results were remarkable.
The test subject, an elite member of the Nightfall Pirates, required three days to fully absorb the serum. During that time, he endured intense physical strain, supplemented by controlled electrical stimulation and massive food intake to sustain the transformation.
When it was over, his height had increased from 2.2 meters to 2.5 meters.
His strength rose significantly, from roughly fifty million Berries to seventy million.
This was a comprehensive enhancement, affecting every aspect of his physical capabilities.
A complete serum, once perfected, could potentially elevate him to the level of a hundred million.
Teach had initially assumed the serum would dramatically increase body size across the board.
He was wrong.
Further analysis revealed that physical growth correlated with baseline strength. Weaker individuals experienced more visible changes, while stronger bodies required less structural adjustment.
For someone like Teach, whose physique already bordered on monstrous, the serum would offer minimal visible change.
Perhaps only a few centimeters at most.
What truly mattered was not size, but potential.
Lifespan. Vitality. Evolution.
Preliminary estimates suggested the test subject's lifespan had extended to approximately one hundred and thirty years.
That alone justified the research. Good things came in succession. With continued refinement, the Super Soldier Serum would soon reach completion. And once it did, it would serve as the foundation for an entire branch of new technologies.
Weakened variants.
Enhanced versions.
Even specialized serums, such as true giantification or demonic augmentation.
After all, in science, every breakthrough opened the door to countless others. The path forward had already begun to take shape.