Air Fortress

"How was I supposed to know he had robots?" Old Dog muttered, despair clear in his voice.

Still, complaints gave way to desperate labor as they hurried to unload the helicopter's cargo. Once everything was cleared, the six began transporting the materials into Mansion No. 13, guided and supervised by the spiders. Each item was placed meticulously into its designated area, no mistakes allowed.

In the basement, the six couldn't help but notice the transformation taking place. Rows of cells were being constructed—cold, confined spaces that left no doubt about their purpose. "These aren't rooms… they're cages," one of them whispered, a chill running down their spine.

Before they could make a move to escape, they turned and saw one of the mechanical spiders silently blocking the exit. Its glowing eyes were locked onto them. "Pick a cell," Zack said flatly, walking in. He glanced at the six incomplete cells, calculating how much longer it would take for the mechanical Ants to finish. "You'll each have one in less than half an hour."

"Wait! Sir!" one of them cried, dropping to their knees. "We're loyal to you! We'll do anything for you! Please, don't lock us up!" One by one, they groveled, their pride long abandoned. These were people who had once worked under Dr. Samson, kidnapping survivors and conducting cruel experiments. They knew better than anyone how monstrous those actions were. Their pleas were desperate, but Zack remained unmoved.

"Enough," Zack said, his voice cold and firm. "This is the best you can hope for."

With a wave of his hand, the spiders sprang into action. Despite the cells still being unfinished, they herded the six into their assigned spaces, sharp legs glinting under the dim lights.

"Watch them." Zack instructed the spider to guard the six captives before leaving Mansion No. 13. It was getting late, and the laboratory renovations still hadn't been completed. Naturally, Zack wasn't going to waste time waiting around. With the situation under control, he planned to focus on what came next—starting the development of the Superhuman Serum the following day.

Back at Mansion No. 9, Zack headed straight to the basement and approached his workbench. "Ego, pull up the files on the Air Fortress and the Air Defense System," he commanded.

As soon as he spoke, two folders materialized on the massive screen before him. One contained detailed blueprints for the Air Fortress, and the other held schematics for an Advanced Air Defense System. Zack leaned forward, his fingers gliding over the screen to open the Air Fortress files. "Plastic gold?" he muttered, raising a brow as he scanned the material specifications. "Never heard of it. Ego, search for alternative lightweight, durable materials with high thermal resistance."

Ego responded promptly, overlaying a list of materials on the screen. Zack selected titanium-aluminum alloys for their high strength-to-weight ratio and carbon nanotube composites for added durability. "Perfect. These will withstand high-altitude conditions and reduce overall weight."

His attention shifted to the power system. "Fuel-powered engines? Are we still stuck in the last century?" He shook his head. "Nope, we're upgrading this to a fusion reactor."

Zack tapped the screen, pulling up a design for a compact cold fusion reactor, a energy source that uses superheated plasma to fuse hydrogen atoms and release immense amounts of energy. "We'll use deuterium and tritium isotopes as fuel," he explained to himself, adjusting the fuel injection system. "They're relatively abundant and efficient for sustained fusion."

He paused, considering the cooling system. "A reactor like this would need a way to handle the extreme heat. Ego, overlay liquid helium cooling channels around the magnetic coils." A schematic updated in real time, showing a network of pipes snaking around the reactor. "This should keep the superconducting magnets stable and prevent a meltdown."

Zack frowned as he studied the thruster configuration. "If we're going with fusion, the propulsion system needs an overhaul too. Ego, let's switch to plasma-based thrusters. They'll work perfectly with the reactor's energy output."

He adjusted the exhaust design, ensuring it could expel ionized gas at high velocities without creating unnecessary drag. "Plasma thrusters will give it the versatility to operate both in atmospheric conditions and in space. Ground-level propulsion will need auxiliary fans, though."

Next, his focus turned to the fortress's defensive capabilities. "This laser interceptor... What a waste if it's only good for short-range." He selected the targeting system and extended its range by integrating adaptive optics to compensate for atmospheric interference. "Let's add a predictive targeting algorithm. It'll track and neutralize threats before they get close."

As the design came together, Zack layered in modular weapon systems. "We'll need railguns for long-range strikes, anti-missile laser arrays, and EMP launchers to disable enemy electronics. Make them easy to replace or upgrade."

Finally, Zack enhanced the fortress's structural integrity. "A titanium-carbon frame reinforced with nano-ceramic plating will keep it light but strong enough to handle direct impacts." He added shock absorption systems to the landing gear and ensured the airlock seals could withstand extreme pressure differences.

One adjustment led to another, and the workload kept piling up. Zack moved between screens, his fingers a blur as he fine-tuned every component. "If the fusion reactor is our power source, we'll need redundant energy storage in case of a reactor shutdown." He designed high-capacity graphene supercapacitors to store surplus energy and provide emergency backup.

By the time the clock struck two in the morning, Zack leaned back in his chair, exhaustion giving way to satisfaction. The Air Fortress now featured state-of-the-art propulsion, defenses, and materials, all grounded in advanced but plausible science. He grinned as he reviewed the final blueprint, murmuring to himself, "Done. This thing's a beast."

Despite the long hours, Zack felt surprisingly energetic. His mental state was sharp, as though he could keep going for hours. "Ego, upload the updated schematics to the Mechanical Ants. I want them to start manufacturing first thing tomorrow," he said.

"Understood, Sir. The data has been uploaded," Ego responded promptly.

Feeling a wave of relief, Zack grabbed a glass of chlorophyll juice delivered by a robotic arm. After taking a sip, he wiped his mouth on his sleeve and headed upstairs. "Wake me at six," he said over his shoulder.

At 5:59 a.m., Zack woke up naturally, beating Ego's alarm by a minute, as usual. He ran a quick self-scan, and the results made him smile. His physical fitness had improved by roughly 3% since the previous day. "Almost 1.8 times that of an average person now," he murmured, clenching his fist and feeling the strength coursing through his body. "But it's still not enough."

After a quick wash, Zack was about to head to the basement when something in the garden caught his eye. Through the window, he saw a red-haired figure throwing punches in the air. Curious, he opened the door and stepped outside. "Didn't expect you to be so disciplined," Zack said, leaning casually against the doorframe.

"Of course!" Erza replied, performing a set of precise military-style punches. Her movements were sharp and well-practiced, a clear sign of her training.

Zack smirked. "You know you're a mage, right?"