High-level martial arts: Contract cashback, invincible starting from the Zerg.

It was a square box that was completely black.

The box was small, about 20 centimeters long and about 10 centimeters wide and high. Its simple and unadorned design was completely out of place in this control room full of high-tech military equipment.

Its surface is completely devoid of any keyholes, buttons, or textures; there isn't even a single seam between the pieces. It appears as if it were carved directly from a single, unknown material.

It is not made of any known engineering plastic or stone. It is smooth to the touch, with an extremely delicate and warm feel, yet it is surprisingly heavy.

"This doesn't seem like something from the Darkin race, Dongcuo. Do you know what this is?"

Chen Feng handed the black box to Xuri Dongcuo.

The identification system of the demon slayer is different. In addition to the information of the main plane, Chen Feng's lucky contract identification system can only identify the biological information of the hunting plane where the contractor is located.

In other words, the recognition level of the Lucky Contract System will gradually improve as the number of contractors of the Exorcist changes.

Xu Ri Dong Cuo held the box up to his eyes and examined it carefully with the help of a flashlight, occasionally tapping the surface of the box with his fingertips.

"This doesn't seem to be encapsulation, but rather an artificially compressed energy body. A massive amount of energy has been forcibly compressed into such a regular cube. The warm feel on the surface is actually an energy barrier formed after the energy has been compressed to the extreme."

"Even our most advanced energy compression technology cannot solidify such a hard and heavy energy entity on a large scale."

Wu Yingguang took a picture of the black box and started using big data analysis.

The AI ​​quickly provided a conclusion.

"This should be an artificial energy body in Beicheng. Its purpose is most likely energy storage. According to the parameters of the box, the energy density compressed inside the box is extremely high, possibly equivalent to the entire storage capacity of a small energy core, or even more."

Chen Feng took the black square box, his fingertips couldn't help but touch it again. This time, he didn't deliberately try to sense the subtle fluctuations.

Yet, one could sense extremely subtle energy slowly surging within the tiny box, no bigger than the palm of one's hand.

"If this is indeed an energy entity manufactured by Beicheng, then Beicheng may already possess the capability to launch long-range attacks against the Upper City," said Xu Ri Dong Cuo.

"Your prediction was correct." Wu Yingguang's Adam's apple bobbed. "We and Beicheng have fundamentally taken two different paths."

The war logic of the Great Xia Upper City has always been anchored on the ultimate breakthrough of individual combat power and the exclusive refinement of close combat weapons, following an elite route of "better to have none than to have bad ones".

Its core combat power is a high-level combat class system with demon tamers like Chen Feng and Xuri Dongcuo at the top.

Whether it's starting as a Yellow-rank combatant, becoming a capable Earth-rank officer, or leading a special envoy group of ten thousand, each promotion is accompanied by a near-cruel talent selection and trial.

Those who can stand at the top of the pyramid in the upper city of Great Xia are all exceptional talents, one in ten thousand, each possessing their own unique talents and family techniques.

For example, the Zerg Hunter Armor and the Demon Slayer Armor used by Chen Feng can freely switch forms according to Chen Feng's will, thus adapting to the close combat scenarios of the Demon Slayer.

The legion structure in the upper city is also built entirely around this elite melee system.

A standard legion of a thousand men is usually led by a powerful Earth-rank expert, accompanied by dozens of Profound-rank combat professionals.

The Northern City, situated in the Giant Beast Wasteland, abandoned its obsession with individual talent from the very beginning, embarking on an extreme path of industrialized mass production of an army. With an endless array of war machines, it built an iron wall that could rival the elite system of the Great Xia Dynasty.

What's even more surprising is that in the decisive battle between Great Xia and Beicheng decades ago, even with more than a dozen Great Xia Desolate Rank experts joining forces to launch a fierce attack, they were unable to directly break through the line of Beicheng's 100,000-strong bio-engineered army.

This case is a result of the comparison between the comprehensive military strength of Daxia and Beicheng, and it has become a nightmare that Daxia's military and political system can never erase to this day.

But what truly kept the Upper City of Great Xia awake at night was never the ground forces of the North City, but their unparalleled long-range strike capability.

As early as ten years ago, Beicheng had already broken through the range and power limitations of traditional artillery and missiles, developing an ultra-long-range energy cannon with an ultra-high-density compressed energy body as its core. This weapon was even deployed on a launch vehicle.

Theoretically, its maximum range can cover the entire territory of the seven border cities, and its accuracy is controlled within ten meters.

The appearance of this black box completely overturned all of the three's tactical predictions.

The ability to compress the energy reserves equivalent to a small energy core into a palm-sized cube and achieve stable solidification means that Beicheng's energy compression technology has achieved industrialized mass production.

They can make this level of energy warhead smaller, more numerous, and with a longer range. They can even mount this ultra-high-density energy warhead onto man-portable rocket launchers, swarm suicide drones, and stealthy guided landmines.

This forms a complete long-range firepower network, ranging from strategic-level full-domain coverage to tactical-level precision strikes.

Chen Feng ran his fingertips along the warm yet cold surface of the black box.

My fingertips could clearly feel the slow, surging, yet terrifying energy within the box, energy powerful enough to destroy the world.

They seemed to have also realized the hidden danger facing the Great Xia Kingdom.

—The Great Xia wields the sharpest blade in the world, making it invincible in war. Yet, in the distant northern city, it possesses the constant power to destroy all of the Great Xia's cities, even its upper cities. This is the power struggle between great nations.