The cause of the explosion being the Edenian submarines that were lurking under the fleets, following them since when they invaded Esparias water.

They were nothing but state-of-the-art in everything when compared to the latest gen of any country's military.

Starting from the energy, these submarines were each being powered by harnessing the energy of a star in the form of fusion reactors. This means that they won't need to ever be refueled as long as they are under the surface of the water. Because these reactors would efficiently extract deuterium, a fuel source, from the surrounding water, rendering themselves self-sustaining during underwater operations.

As for the propulsion system it too was the state of the art magnetic propulsion helping the submarine in its stealthiness while at the same time allowing it to go at unimaginable high speeds.

In place of sonar, these submarines utilized the same advanced scanner as the one that was scanning Eden's airspace, meaning they were aware of anything that existed around them within a bubble of 500 kilometers of radius.

Giving them a frightening awareness wherever they were, making them an enemy you don't want to face under any circumstances.

The hull of the submarine was made from a revolutionary material, a marvel born from the result of the research done in laboratories of Lab City, where they had managed to make dream materials for any submarine maker in the world.

The hull material exhibited the remarkable hardness of diamond coupled with an exclusive flexibility that absorbed and dispersed any impacting energy, negating any risk of cracking or fracturing. This innovation ensured the hull's capability to endure immense pressures of the deep-sea domain, ensuring both the submarine's safety and structural integrity even at extreme depths. Furthermore, the materials lightweight nature, in proportion to its strength, elevated the submarine's buoyancy and maneuverability, simultaneously reducing the vessel's overall weight burden.

Resistance against the corrosive and erosive forces of saltwater exposure? The material stood resilient, impervious to degradation. This resistance translated to a prolonged lifespan for the hull, simultaneously, effectively reducing the demand for frequent maintenance requirements. Furthermore, the unique composition of the material manifested in its exceptional ability to absorb and dampen the sound waves, rendering the submarine nearly silent and drastically curbing its acoustic footprints. This transformation bolstered the vessel's stealth capabilities, enhancing its covert operations even further.

Notably it was also adaptable to fluctuations in temperature. The material seamlessly adjusted to varying environmental conditions, ensuring a stable internal environment, eliminating any concerns linked with thermal conductivity. The sole drawback lay in the complexity of its manufacturing process, an obstacle that was effortlessly circumvented by Aron, who harnessed atomic printing technology, making the fabrication process seamless and expedient.

As for the rest of the interior of the submarine, it was mostly nothing other than differently tuned atomic printers which were tuned and placed in different locations to accomplish diverse functions.

Everything from the torpedo tubes, SLBM (Submarine launched Ballistic Missiles) tubes, kitchen, bathrooms and everything else other than the operation room and sleeping quarter was filled with atomic printers and tankers that were stocked with atoms required for making the product.

During meal time, all a soldier had to do was go to the kitchen and they would find a very presumptuous hot meal that was already printed for them.

If they needed to fire torpedo missiles, the atomic printer on board the torpedo tube would simply print the torpedo before it would be fired, this gave the submarine a rapid firing ability as they didn't have the limitation of the traditional slow reloading of the torpedoes.

All of this resulted in these submarines being the world's most heavily armed submarines while it didn't have anything that could be considered as a fire hazard in it. Having a hull that was as hard as a diamond, they would always maintain communication with the main base no matter where they were since they were using quantum computers as their submarine's computer giving them the advantages of seamless quantum communication.

The submarines, designed for stealth and capable of massive ordnance delivery from anywhere on Earth to any location, of course, went completely undetected by the outdated sonars that were on the Esparian fleet, allowing for them to roam and follow them as freely as they wanted without having to worry about being discovered.

...

The moment the fleets commenced firing with the intention of saturation, an order was finally relayed from Athena to the submarines. At that time, half of their crew was inside the control room with the other half, having completed their shifts, resting or engaging in other recreational activities within the VR.

The submarines were currently operating as if it was a normal patrol mission which relieved the need for all the personnel to be on deck. That is why they were so relaxed and not because of their own arrogance, but rather because those were the orders from the higher-ups.

"Load and flood the torpedo tubes," the submarine commanding officer wasted no time before ordering for the torpedo tubes to be loaded and flooded with water in preparation for the impending attack.

The soldier in charge of the weapons deployment immediately executed the order, initiating the approval for the production and loading of a torpedo into the torpedo tube.

Upon receiving the command, the atomic printer in the torpedo tube sprang into action. It accessed the raw materials stored and efficiently printed the entirety of the torpedo before filling the tubes with water in just a few seconds which was then followed by the torpedo door being opened, presenting the loaded torpedo that was waiting to receive the firing command.

"The torpedoes are loaded and tubes are flooded," reported back the weapons deployment specialist.

"Fire!" the commander officer uttered calmly, which was immediately responded to as all four freshly crafted torpedoes were launched in rapid succession.

As the torpedoes exited the tube, they released a subtle sound that was immediately absorbed by the water surrounding it. The magnetic propellers came to life and started spinning, propelling the torpedoes out of the tube as they started their journey to their targets among the fleets, which were just a short distance away from the submarine.

The torpedoes did not take more than a few seconds to arrive closer to the surface of the water, unfolding a magic moment upon the water's surface

The torpedo continued its trajectory until it positioned beneath the target ship, at which point it detonated.

The explosion generated an underwater bubble that propelled the ship to rise momentarily upward, absorbing the initial impact. Almost immediately, the underwater bubble began to collapse as the water rushed in to fill the void.

This sudden compression forced the ship, still slightly elevated, to drop abruptly before being thrusted back into the air once again, reaching an even greater height than before.

The swift ascent was driven by the surge of water rushing in to fill the void left by the collapsing bubble, displacing the air that had previously occupied that space. This influx of air acted as the final catalyst that propelled the ship higher into the air with even greater force.

Under the strain of such an intense barrage of pressures, the vessel succumbed, fracturing into two distinct parts while still being suspended mid-air.

As the ship split apart, it began its descent, ultimately plummeting into the water below.

The impact with the water was immediate, and the vessel quickly began to take on water.

Among the ensuing chaos, the surviving soldiers aboard the ship struggled to escape the rapidly shifting and turbulent waters, which were now far from being calm due to the explosive sequence of events that had unfolded in a fraction of a second.