On the ground battlefield of Callisto Second Fortress. Both the Earth Forces and the Ancient Legion had been preparing for this assault for two full days, having poured their utmost effort into securing the Second Fortress. The Earth Forces deployed five times the ground troops they had used against Fortress One, all rushed to Callisto in those preceding days.

The garrison of Fortress Two was by no means inferior to the Earth Forces; the number of newly erected automated defense turrets was beyond counting, pushing the engineering capabilities of the space age to their limit.

Under the operation of thousands of engineering robots, a defensive system covering an area of one square kilometer could be completed in half a day. Furthermore, the Ancient Legion possessed an uncountable number of engineering robots, as the Ape population itself was relatively sparse. The battlefield frequently utilized weapons like robots, alongside Ancient Behemoths, to bolster combat strength.

Both Callisto and Europa possessed extremely thin atmospheres, environments where Ancient Behemoths were not ideally suited for deployment. Consequently, they were rarely seen here.

Ahead of Fortress Two, three Thor units advanced relentlessly forward. Dozens of kilometers behind them, ranks of Siege Tanks set up their massive cannons, bombarding the automated defense turrets that had suddenly sprung up around the impact craters.

Swarms of dark, dense Ape fighters pressed toward the Earth Forces. Simultaneously, dark hatches suddenly opened in the distance, disgorging mixed units of Ape infantry and Combat Robots. Directed by the Ape infantry, the Combat Robots advanced with synchronized, disciplined steps, moving in tight square formations.

Observation from the skies indicated that these Combat Robots numbered close to a million. Each square formation was fifty by fifty, totaling twenty-five hundred units, with over a hundred Ape soldiers positioned outside each formation to maintain control. And there were over four hundred such formations.

The Combat Robots were skeletal and gaunt, appearing almost like the bare framework of an Ape skeleton, covered only by a thin layer of armor. They carried standard issue Hammerfire Rifles, though a small fraction were equipped with anti-tank rockets, plasma cannons, and other high-lethality weaponry.

“Just the Combat Robots here account for one-tenth of the entire Ancient Legion Ape population. Truly cannon fodder of the cannon fodder—so cheap,” remarked one avatar sitting inside a Thor, shaking its head.

“Only with these thoughtless cannon fodder can they generate shock impact through formation fighting. If they were intelligent beings, a single barrage would result in utter slaughter within such dense ranks, and morale would vanish instantly,” commented another avatar.

“I recall reading somewhere that one robot is a worm, but a swarm of robots is a dragon. It was said that due to the rigid nature of robot AI programming, formations like these are best, as unified command is much easier to implement,” the third avatar concluded.

Although the Thor was equipped with a significant array of weapon systems, a single Thor would not hesitate when facing one formation of Combat Robots. However, against such overwhelming numbers, it could only rely on neighboring units for support.

Beside the Thor units, the thirty thousand Earth Forces ground troops had fully deployed: Tanks formed the vanguard, followed by skirmish lines composed of Hoverbikes and infantry, advancing toward the Ancient Legion.

The artillery batteries in the rear had also been established, unleashing massive firepower from cannons of various calibers onto the Combat Robot formations. A single shell landing within a robot formation could blast a significant gap.

Conversely, whenever an Ancient Legion shell struck Earth Force units, armored vehicles were flipped over, and infantry were blasted tens of meters into the air.

Both sides advanced through the smoke and haze, marching while firing. The lines slowly closed.

At this moment, about fifty kilometers out on the Earth Forces’ flank, several dark hatches suddenly opened, revealing vast missile launch sites. The honeycomb launch bays erupted in rapid bursts, sending rows of missiles trailing flames and plumes of white vapor directly toward the Earth Forces.

Within the Earth Forces deployment, several missile interceptor vehicles blared urgent alarms. Drivers immediately activated their systems, deploying launch ports from their chassis, sending volleys of counter-missiles toward the incoming swarm.

As the interceptors neared the enemy missiles, their warheads detonated, scattering thousands of egg-sized bomblets that formed a vast, net-like barrier.

When the Ancient Legion missiles struck this web, the smaller bomblets instantly exploded, creating what appeared to the Earth soldiers as a sudden curtain woven from pure flame. The bulk of the incoming missile swarm detonated against this curtain, neutralized of their immediate threat.

However, after the initial intense explosion subsided, a second wave of missiles pierced the now-thinning curtain and continued their trajectory toward the Earth Forces.

Interceptor missiles were launched again, but this second wave was not entirely intercepted. Some missiles slammed into the ranks, causing massive devastation.

A single missile explosion could clear everything within a hundred-meter radius, leaving not even steel intact.

Seeing this, the three Thor units immediately swiveled their main barrels toward the Ancient Legion’s missile base. Two Level-Five Hammerfire Cannons and four Level-Four Uranium Cannons fired simultaneously, instantly obliterating nearly half of the missile base structure.

Suddenly, a third wave of missiles erupted from the base, launching directly at the three Thor units—a swarm numbering over ten thousand.

Clearly, the Ancient Legion considered the three Thor units to be high-priority targets.

Thors were mobile gun platforms, heavy artillery platforms, and allowing such powerful assets to roam so freely was extremely dangerous.

Faced with a seemingly endless stream of missiles, the Thors deployed all their external interceptor missile ports, alongside dozens of Level-One Uranium Rotary Cannons, returning fire against the incoming barrage.

Concurrently, the Earth Forces’ interceptor missiles were also launched. The two missile clouds met in the middle, once again drawing the curtain of fire.

Some enemy missiles penetrated the curtain but were intercepted by the Thors’ Uranium Rotary Cannons, exploding into shrapnel mid-air.

While dealing with the incoming missiles, the Thors continued their bombardment using the heavy cannons mounted on their arms and shoulders against the launch base. As the beams struck, after two minutes, the entire remaining missile base was swept by the three Thors, destroying every exposed launch port.

During this exchange, the automated defense cannons of Fortress Two focused their fire onto one of the three Thors, causing it to stagger several times and retreat momentarily.

Yang Ying’s avatar within the cockpit felt the jarring vibrations but certainly wasn't enjoying the ride.

After retreating a few steps, it stabilized. As the smoke cleared, the Thor remained completely unharmed.

“What incredibly thick armor.”

“Is this warship-grade plating?”

“They have two Uranium Cannons—they must be Level-Five.”

“I knew that three days ago. Their Uranium Cannons can flatten a small mountain; how could less than Level-Five firepower suffice?”

“Fierce firepower, thick armor, and decent speed—it seems capable of adapting to all forms of ground warfare. Truly a perfect design. I wonder when we can equip the general army with them?”

“When a weapon debuts with such flair—both practical and possessing such an overwhelmingly powerful appearance—other military corporations’ armories will likely rush to research and manufacture copies,” one commented.

“‘Rush to research and manufacture’? Easier said than done. This colossal machine encapsulates countless technological breakthroughs. Do they think their weapon researchers are gods, capable of reverse-engineering just by looking at the exterior?”

In a massive, three-story command vehicle far in the distance, several high-ranking Earth Force generals watched the Thor’s performance on optical displays. Their eyes shone like 100-watt bulbs, filled with satisfaction and praise.

A few minutes later, the Earth Forces’ armored units and the Ancient Legion’s Combat Robot formations finally collided. The tanks pivoted their cannons, firing shell after shell into the robot formations.

Simultaneously, concentrated bursts of anti-tank rockets launched from the robot formations to counter the tanks. The advantage of formation fighting became evident here: immense concentrated firepower that could easily punch through enemies lacking sufficient depth.

Tanks facing the robot formations were destroyed one by one, yet despite losing several hundred units, the formation maintained sufficient combat effectiveness.

As they advanced, the robots did not scatter; instead, they drew tighter, closing the gaps blown open by artillery fire, coalescing into an even smaller, denser square.

At this point, Earth Force artillery fell silent because the two sides were already engaged in close combat, intermingled. Firing shells risked hitting friendly troops.

The robot formation thus pressed deep into the Earth Forces' lines, pushing further inward.

Tanks and armored vehicles positioned toward the rear continued firing into the formation. One tank had its turret damaged, but seeing the robots bearing down on it, it slammed its engines to full power and rammed straight into the formation.

Two anti-tank missiles launched from within the formation completely blew the tank’s turret skyward, but the chassis continued its momentum, crashing into the robot ranks.

Over a dozen robots were crushed beneath the tank. The remaining ones showed no reaction, coolly continuing their advance, splitting into two streams to maneuver around the wreck before merging again, reforming their square and pushing onward.

They smashed through several lines of defense before reaching effective close-quarters combat with the infantry, at which point the Earth Forces finally managed to exhaust the robots in that single formation.

And that was only the first rank of formations; there were still over three hundred more advancing toward the Earth Forces’ lines.

Upon seeing this, the three Thors strode to the very front line, aiming the muzzles of their twin arms at one intact robot formation. Six searing beams of light sliced through the formation, instantly vaporizing over a thousand robots, while the resulting massive explosions tore the entire formation apart.

Dozens of Rotary Cannons deployed on the chassis of each Thor, showering the dense robot ranks with concentrated beams of light, reaping them down like cutting grain—swift and precise.

Anti-tank rockets striking the Thors felt like mere pinpricks, no more bothersome than the artillery shells. Plasma cannons, however, proved more troublesome. They could melt the Thor’s outer armor plating. A few plasma cannons hitting the same spot on the leg armor simultaneously caused the plating to become pitted and scarred.