Days had passed since the United Coalition Alliance's assault on Rhodope Village, where they had successfully driven out the occupying Zeon forces and seized control of the enemy base. In the aftermath, the UCA worked tirelessly to aid the villagers, distributing food and water supplies to ensure their survival. With their advanced replicator technology, they had no fear of scarcity—resources could be endlessly reproduced, allowing them to sustain both their own forces and the people of this alternate universe.

Meanwhile, within the captured base, UNSC engineers and scientists from three human factions worked diligently to reverse-engineer the Zeon mobile suits now in their possession. It was a monumental step forward—finally, the UNSC could field their own mechanized units to match those of their adversaries. The teams meticulously dismantled and studied the mobile suits, implementing modifications to enhance their agility and maneuverability. Borrowing neosteel from the Dominion, they reinforced the frame, significantly improving durability against enemy fire.

After hours of rigorous engineering, their efforts bore fruit. The first UNSC-built mecha stood complete, a fusion of Zeon technology and UNSC innovation. It was bulkier than the sleek GDI mecha fighters but retained a rugged, battlefield-ready aesthetic. Excitement rippled through the ranks of UNSC personnel, who gathered to witness the unveiling of their first true mechanized war machine. As discussions arose about naming the unit, a Marine humorously suggested "Greenhorn"—a term familiar among their ranks. To everyone's amusement, the name stuck, and with unanimous agreement, the new UNSC mech was christened Greenhorn.

With production underway, engineers began developing weaponry tailored for the Greenhorn, integrating UNSC ballistics with energy-based technology derived from Covenant, Banished, and Forerunner origins. Thanks to replication technology, manufacturing the mechs and their armaments became a streamlined process, ensuring the UCA's forces would not be outmatched in future battles.

During this time, negotiations took place between Captain Lasky and Ivan Antonov, the leader of the local resistance. Gathered alongside representatives from the UCA's various factions, they discussed terms of cooperation. Antonov agreed to allow the United Coalition Alliance to establish a secure foothold in the region, granting them a large territory to operate from. In exchange, the UCA pledged to share information about their origins, fostering mutual trust.

As part of the agreement, Antonov requested that his resistance fighters be trained as an organized militia—one dedicated solely to the defense of their homeland, steering clear of direct involvement in the larger war between the Earth Federation and Zeon. Additionally, he proposed that his daughter, Luna Antonov, serve as a liaison between their factions. She was eager to learn about the UCA and their advanced technology, believing that her knowledge could aid both her people and their newfound allies.

In an unexpected display of trust, Antonov and his people also pledged their loyalty to the UCA. They vowed to keep the alliance's presence a secret from the Earth Federation, a government they viewed as corrupt and self-serving. To the resistance, the Federation was a bureaucratic machine, its politicians more concerned with personal gain than the well-being of the people. Their failure to protect vulnerable regions—abandoning them to Zeon occupation while focusing their war efforts elsewhere—had long since shattered any faith the locals had in their so-called leadership.

Yet, while life in the village gradually stabilized under the UCA's protection, the war beyond their borders raged on. The conflict between the Earth Federation and Zeon showed no signs of waning, and in the shadows, forces unknown to the UCA continued to lurk—silent, watching, waiting. Their next move was uncertain, but one thing was clear: the battle for this alternate reality was far from over.

...

With Zeon mobile suits in their possession, they can finally study their capabilities and reengineer them to create their very own mecha robots, capable of combat on equal footing with other mobile suits. The UNSC successfully produces a single mecha robot and showcases its appearance and design to everyone. While brainstorming a name for it, a single marine suggests "Greenhorn" due to its green-colored design resembling the marine. The name is put to a vote, and Greenhorn becomes the official designation. Now, they begin mass-producing these mecha robots to effectively counter enemy mobile suits while training new pilots, particularly marines or ODSTs, who have never piloted one before. It's evident that piloting these mecha robots requires significant skill and combat experience against the enemy. They even plan to develop special mecha robots tailored for Spartans, utilizing their combat skills to engage mobile suits with similar movements and integrating the data to enhance the mecha robots' mobility, speed, and agility in battle.

Halsey provided the allies with the blueprints necessary to create vehicles and aircraft based on designs she stored on her personal data pad. Additionally, she possesses a highly classified blueprint that was supposed to be erased during the Human-Covenant war: the HRUNTING/YGGDRASIL Mark I Prototype Armor Defense System. This prototype experimental exoskeleton mech suit was slated for erasure during the Algolis Invasion, yet certain ONI personnel like Halsey retained copies of the data, potentially to serve as a trump card to shift the tide of war. However, with the war concluded, the need for the prototype mech suit diminished, and focus shifted to other military projects.

Now, Halsey recommends to Lasky and the others the construction of the Mark I Prototype Armor Defense System exoskeleton suit, with enhancements such as a new energy source and armaments to increase effectiveness against stronger foes. After debates and discussions, they accept her recommendation and initiate production of the newly enhanced exoskeleton combat mecha suit. This project is dubbed "Project Hoplite" and is intended for use by marines or ODSTs in various combat scenarios. Spartans will also have access to mecha suits when necessary for combat engagements.

Not only will the UNSC have their own mecha robots, but the Terran Dominion and the Daelaam will also develop their own to match mobile suits evenly. Production has commenced on mecha robots tailored to each faction's unique design specifications. It will take some time for all three factions to complete production and acquire their own mecha robots, allowing them to confidently confront mobile suits on equal footing.

...

UCA Bravo Rhodope Base

Luna Antonov wandered outside of UCA Bravo Rhodope Base, her keen eyes observing the flurry of activity around her. Despite being perceived as an ordinary civilian, she remained in her casual attire, blending into the bustling environment. As she glanced around, her gaze settled on a burly man with a dark beard, hauling heavy crates toward a waiting Pelican dropship. With a final grunt of effort, he loaded the last crate and wiped sweat from his brow. That was when he noticed her approaching.

"Oh! You must be... a little girl?" he remarked, his voice tinged with curiosity.

Luna scowled. "Hey! I'm seventeen. And I'll be turning eighteen soon."

The man chuckled. "For a young girl like yourself, you've got quite a bit of bravado, especially at seventeen."

"Ha, ha, ha... Very funny," she shot back sarcastically before settling onto a nearby crate, swinging her legs idly. He finished his tasks and decided to join her, sitting down beside her.

"So... You're checking out the place, huh?" he asked.

"Yeah. I've never seen such advanced weaponry and arsenal in any military before. Not even the Federation has anything like this."

He laughed. "Ha! The Federation is pretty primitive compared to our advanced technology and modern military infrastructure."

He reached for a bottle of water, taking a few gulps before continuing. "I'm guessing they've told you a lot about us."

It was true. Luna and her father had been informed by the leaders of the UCA that their origins lay in different universes, a concept that was almost too overwhelming to fully comprehend. Wars had been fought on a scale far beyond the Federation-Zeon War. Humanity had clashed with itself, from insurrectionists to the Brotherhood of Nod and the warring Terran factions of the Koprulu sector. But when they spoke of extraterrestrial conflicts—battles against the Covenant, the Scrin, the Zerg, and the Protoss—Luna and her father were left in stunned silence. The sheer number of casualties in these conflicts dwarfed anything the Federation and Zeon had ever witnessed. The leaders had urged them not to disclose this information unless explicitly instructed when their presence in this universe was finally revealed.

Luna absentmindedly brushed her hair aside, her thoughts lingering on that surreal meeting. It was still difficult to believe.

"I can't believe you're actually from different universes where humanity has expanded beyond the solar system, colonizing planets across entire sectors. Except... there's still war involving humanity itself. And then... aliens. Yeah, aliens are real!" She let out a breathless laugh. "It's mind-boggling to think that we're not alone in space, that there are aliens out there, just living their lives. And then there are the bad ones who come to challenge humanity. Well, except for the good ones, like your Protoss friends and that Sangheili guy—your former enemy—who now wants to wipe out our kind in the name of religion, but somehow became an ally..."

She let out a heavy sigh and fell back onto the crate, staring up at the sky.

"You know," she mused, "you folks from the UNSC, GDI, and the Terran Dominion always have the most advanced technology. You colonize planets instead of just building giant space colony stations and staying within the solar system."

She turned her head slightly. "Our universe really sucks, doesn't it? While you guys expand beyond the stars and build a better future, we just fight over petty political ideologies and other nonsense."

Fernando, as she now recalled his name, shook his head. "Hey, don't say that. Sure, humanity always finds a way to fight over the stupidest things. But there are people like you and me who want something better. We push beyond the stars, explore, and build new homes for our kind to thrive. Yeah, there'll always be conflicts, but at least we strive for a better future."

Luna chuckled. "A better future... I wish everyone shared your mindset. But both the Federation and Zeon don't see it that way."

"Hmm... because of corrupt bureaucrats, politicians, and the Zabi family dictatorship? Yeah, I can see why."

Before Luna could respond, a towering figure approached.

"Ah, Karra. Nice of you to show up," Fernando greeted.

The Sangheili warrior gave a slight nod. "I have finished inspecting the plasma weaponry for the UNSC personnel, in preparation for engagements against our enemies—including the Zeon."

He turned his gaze toward Luna and extended his hand. "I am Karra Vastoree. It is an honor to meet someone from this universe."

She shook his hand, though her fingers barely wrapped around his. "Nice to meet you too."

After a brief pause, curiosity got the better of her. "So... what planet are you from? I know they told me about aliens, but I want to hear it from you."

Karra chuckled. "You wish to know about my homeworld? Very well. My home is Sanghelios, a planet where my kind resides."

"What's it like?"

"We Sangheili are born as warriors, following a strong tradition of honor. Our world is ruled by kaidons—clan leaders, in your terms. At present, it is under the leadership of the Arbiter, Thel 'Vadam. He has united the fractured clans after a civil war against the remnants of the Covenant. With our blades, we have vanquished those who deceived us and freed our world from their lies."

Luna's eyes widened. "Wow... So your entire society is based on warrior beliefs?"

Karra nodded solemnly.

"That sounds cool," Luna admitted. "I really admire you guys fighting for honor... Well, except, you know..."

Karra sighed. "Yes, I understand. I, too, was once a misguided warrior who believed in the Great Journey, who worshipped the Forerunners as gods. We committed genocide against humanity, only to learn the truth: we had been deceived. The prophets used our faith to control us. Humanity was the true inheritor of the Mantle of Responsibility. I am ashamed of our past actions, as are many of my kind. Now, we seek redemption by standing alongside humanity."

Luna absorbed his words, her earlier anger softening. "Well... it doesn't matter now. The Covenant is gone, and so are the prophets. You got your revenge, and in the end, everything worked out."

Karra gave a thoughtful nod. "Perhaps. Still, if I had encountered the Prophet of Truth before the Arbiter did, I would have cut him down and listened to his screams as he perished."

Fernando let out a low whistle. "Damn. That's dark."

Luna smirked but quickly shifted gears. "So, I heard you guys are planning to start building your own mecha robots, equivalent to mobile suits. GDI already has their own mechs, and their pilots are highly disciplined. Unlike the Federation's soldiers."

She hopped off the crate. "By the way, do you think Zeon will find out they lost this base?"

Karra crossed his arms. "We cannot be certain. But if they discover what has happened, they will send reinforcements to reclaim it."

Luna grinned. "Then let them come. We'll be ready."

...

UCA R&D Laboratory Facility

The hum of machinery and the faint glow of holographic displays filled the laboratory as scientists from various factions worked tirelessly, pushing the boundaries of technological innovation. Among them, Dr. Catherine Halsey moved with purpose, her sharp eyes scanning the progress of their latest research. She was not alone in her efforts. Dr. Liang, the head of the GDI Science Division, stood at one of the workstations, overseeing his team as they meticulously examined blueprints for mecha enhancements.

The collaboration between these scientific minds was unprecedented—each faction bringing its own wealth of knowledge, united by the common goal of advancing weaponry and equipment. They worked not only to enhance existing technology but also to reverse-engineer both human and alien designs, striving to create weaponry that would give their forces an undeniable edge.

Dr. Halsey approached Dr. Liang from behind, her presence quiet but unmistakable.

"Hello, Dr. Liang," she greeted.

Dr. Liang turned, offering a nod of acknowledgment. "Ah, Dr. Halsey. Good to see you. How's the reverse engineering of the Forerunner weapons progressing?"

"Quite smoothly," she replied, a hint of satisfaction in her tone. "With my expertise in Forerunner technology and Dr. Glassman's assistance, we've managed to successfully reverse-engineer several key components. We've already integrated them into both infantry weaponry and mechs. Additionally, we've been testing a new mecha prototype with enhanced joint mechanisms—its improved mobility allows pilots to move faster in all directions."

Dr. Liang stroked his chin thoughtfully. "That's promising news for the UNSC. And what about the weapon systems for these mechs?"

"I've already taken care of the framework," Halsey assured him. "What we need now is to modify the weapons to accommodate high-explosive rounds capable of effectively neutralizing enemy mechs."

Dr. Liang raised an eyebrow. "And I assume that's where we come in?"

"Precisely," Halsey said. "I've heard that GDI maintains a sizable stockpile of high-explosive ammunition for their infantry units. Would it be possible for us to acquire a portion of that stock?"

Dr. Liang considered the request for a brief moment before nodding. "That shouldn't be a problem. I'll inform the admiral and have the necessary authorization secured. The transfer will be arranged."

"Excellent," Halsey said, a rare smile ghosting her lips. "This partnership of ours is proving to be quite beneficial. As long as our alliance remains intact, I believe we can accomplish great things."

Dr. Liang smirked. "Indeed, Dr. Halsey. Indeed."

The collaboration between the UNSC and GDI was still in its early stages, but with each breakthrough, the future of their technological advancements grew ever more formidable.

...

Bulgaria

Zeon Military Base

The air was thick with the scent of oil and metal, the ever-present sounds of machinery echoing through the Zeon military base. Deep within the heart of the compound, General Canard Suu sat in his office, poring over intelligence reports and logistical assessments. His mind was occupied with preparations for the next phase of their campaign against the Earth Federation—until an abrupt knock at the door shattered his concentration.

Before he could respond, the door swung open, and a Zeon soldier stepped inside, standing at rigid attention.

"General Suu, sir!" The soldier saluted sharply. "I must report from the radio communication center. We've lost contact with Brigadier General Roher in the Rhodope territory."

Canard Suu's head snapped up, his eyes narrowing. "What?"

He rose from his chair with urgency, his pulse quickening. Brigadier General Roher had been tasked with establishing a critical base of operations in the Rhodope region—an effort meant to solidify Zeon's hold over Bulgaria. His sudden radio silence was more than just an inconvenience; it was a glaring red flag. Losing contact with an entire operational unit meant that something—or someone—had disrupted their plans.

"Have you attempted to reestablish contact?" Suu demanded.

"We've made several attempts, sir," the soldier confirmed.

The general exhaled sharply, rubbing his temples. "Wonderful. Just what we needed." His gaze turned steely. "If we don't act quickly, the Federation might seize this opportunity to retake Bulgaria. Do we know if the guerrilla fighters are responsible for this?"

The soldier hesitated. "I... I'm not sure, sir."

Suu's eyes darkened. "What do you mean you're not sure, private?"

The soldier swallowed, his voice tightening. "We can't confirm it. All video recordings from our mobile suits have been wiped out. Every single data log—completely erased."

Suu's expression froze. "What?" He clenched his fists. "That's impossible! There's no way our mobile suit recordings could have been wiped out so easily!"

His mind raced. If the data had been erased, this wasn't just a standard guerrilla attack. This was something far more deliberate—far more dangerous.

Gritting his teeth, he made his decision.

"Very well," he said, his voice firm. "Send half of the battalion to the Rhodope territory to retake it."

The soldier blinked. "Sir?"

Suu stepped forward, his jaw set in determination. "That location is crucial to our operations. It's the key to reinforcing our forces and securing vital resources from the mountains. We cannot afford to lose that foothold." His gaze hardened. "Have Commander Rudolf Butsham lead the battalion. I want that base back—at any cost."

The soldier snapped to attention once more. "Right away, sir!"

As the soldier turned and exited the office, Canard Suu remained still, his hands clenched behind his back. Something had gone terribly wrong in the Rhodope territory. And he intended to find out exactly what—or who—was responsible.

...

UCA Headquarter

The war room was filled with a tense hum of discussion as Lasky and the other faction leaders sat around the central table, debating their next course of action. After securing the region from Zeon attacks and integrating it into their growing territory, they now faced a pressing issue—resources.

While their replicators allowed them to generate supplies, materials, and even weaponry, relying solely on technology had its limits. Traditional resource extraction remained the most efficient way to sustain their war effort. This alternate Earth, untouched by modern industrialization, held untapped reserves buried deep within the mountains—a perfect opportunity for resource exploitation.

Hackboar leaned forward, tapping a finger against the holographic display of the nearby mountain range. "We believe these mountains contain rich mineral deposits—exactly what we need to bolster our military arsenals."

Lasky nodded. "Agreed. We should begin construction on a laser drill. It's the fastest and most efficient way to breach the mountain and extract what we need."

Xuroth, a representative from his own faction, crossed his arms. "We can assist with its construction. Our probes are capable of handling the assembly, but it will take a few minutes to complete the drill."

Hackboar smirked. "Actually, I already have one on my ship. We can transport it here, assemble the parts, and activate the Drakken laser drill. That'll save us time."

Lasky considered the plan before turning his attention to Admiral MacArthur. "What are your thoughts, Admiral?"

MacArthur, a veteran of countless battles, stroked his chin thoughtfully. "I concur. We should proceed with the laser drill plan immediately."

Lasky nodded. "Then it's settled. We'll coordinate transport and assembly at the mountain site and begin excavation as soon as possible."

Just as the meeting seemed to reach a resolution, a flickering blue light formed beside Lasky. The holographic figure of Roland, the AI overseeing intelligence operations, materialized with an urgent expression.

"Captain Lasky, we have a problem."

Lasky straightened. "What is it, Roland?"

"InOps reports that one of our recon drones has spotted a battalion of Zeon forces heading directly toward our position."

A heavy silence fell over the room.

Roland continued. "It appears that after we seized their base in Rhodope, they realized reinforcements weren't coming. Now, they're sending a battalion to retake it."

Hackboar cracked his knuckles. "So, they're up for round two, huh?"

Xuroth's expression darkened. "Indeed. My observer has also confirmed their approach. They're bringing mobile suits this time."

Roland's voice remained steady as he listed the enemy forces. "They've deployed aerial support as well. I've counted five Dora fighters, five Fat Uncle transports carrying mobile suits, three Gaw attack carriers, four Battle Helis, and ten Dodai Ga bombers. Additionally, there are twelve Wappa patrol hovercrafts sweeping ahead."

Xuroth added his own reconnaissance findings. "On the ground, their forces consist mostly of infantry. In terms of armor and transport, they have ten APCs, nine Magella Eins tanks, five transport trucks, eight light jeeps, and five Magella Attack main battle tanks."

MacArthur let out a low whistle. "Damn. They're throwing everything they've got at us. Seems excessive for one base, doesn't it?"

Hackboar scoffed. "They must really want it back. Even if it means deploying an entire army to do it."

Lasky narrowed his eyes, his mind piecing together the bigger picture. "No... it's more than just reclaiming lost ground. If I had to guess, they have the same objective we do—those mountains."

Xuroth nodded in agreement. "If that's the case, then we need to eliminate their forces and push forward. Capturing one of their bases would give us a foothold in the region, cutting off their supply lines and preventing them from regaining momentum. If we weaken them enough, they'll struggle to continue their war against the Federation."

Lasky glanced around the room, meeting the determined gazes of his allies. "Then it's decided. Stay alert, everyone. A battle is coming."

...

Zeon POV

The rhythmic thudding of boots against the dirt road echoed through the valley as the Zeon battalion advanced toward Rhodope. Leading the charge was Commander Rudolf Butsham, perched atop a Weasel APC, his sharp eyes scanning the terrain ahead.

Draped in his green Zeon officer uniform, his rank insignia gleaming under the sun, Butsham carried himself with an air of absolute authority. He was a staunch believer in Gihren Zabi's ideology, a nationalist who saw Spacenoids as superior beings, destined to rule over the so-called Earthnoids. The very thought of those who sided with the Earth Federation disgusted him, and he had made it clear—any Spacenoid who betrayed Zeon would meet the same fate as the fallen Side 4 colonies.

Butsham's fists clenched at the memory of their humiliating loss in Rhodope. Their brigadier general had been killed, and worse, their base had been overrun by the locals. Earthnoids—defeating Zeon soldiers? Impossible. There had to be more to this. A deeper scheme at play.

The Feddies.

It was the only explanation. The Federation must have been aiding the locals, orchestrating this rebellion from the shadows. His thoughts darkened as he reached for his headset communicator, tuning in to one of his officers.

"This is Commander Butsham. Have you dispatched the two Lungguns for reconnaissance?"

A crackle of static followed before the officer responded. "Yes, sir. They were sent to the enemy's last known location a few minutes ago... but we lost contact with them shortly after."

Butsham's brow furrowed. "Is that so?" He exhaled sharply. So the Federation had already taken action. If their recon units had gone silent, there was little doubt—the enemy had spotted and shot them down.

"Remain vigilant as we approach the enemy's location."

"Roger that, sir."

With a cold click, Butsham ended the transmission.

His grip tightened around the APC's railing as his scowl deepened. Damn those Earthnoids.

"How did we lose our base to them? Was the brigadier general too weak to handle mere locals?" He spat the words like venom, his voice laced with contempt. But in the end, it hardly mattered.

I will succeed where he has failed....

...

UCA Rhodope territory

The air in Rhodope was thick with tension. A warning had gone out—Zeon forces were approaching. Across the UCA military encampment, soldiers and militia alike scrambled into position, bracing for the impending battle.

The Rhodope militias, determined to protect their homeland, stood ready. Some prepared to fight alongside the UCA forces, while others remained behind, guarding the village in case of an airborne assault. If Zeon intended to drop paratroopers, they would find no easy victory here.

Among the defenders was Ivan Antonov, leading his militia group as they integrated with UCA forces. Unlike before, when they had relied on conventional arms, they were now being equipped with advanced weaponry. Stepping beyond the GDI-constructed walls, they moved toward the barricades, scanning the horizon for any sign of the enemy's approach.

Meanwhile, in the depths of the UNSC Mecha Factory, Master Chief and Blue Team observed as engineers worked tirelessly on their latest creation—combat mecha designed to counter Zeon's mobile suits. Sparks flew from welding torches, and the rhythmic hum of machinery echoed through the massive hangar. Standing at the forefront was Dr. Henry Glassman, one of the last surviving chief engineers of the UNSC. He adjusted his glasses before turning to the Spartans.

"Spartans," he began, his voice carrying an air of excitement, "while you were training, we recorded your combat movements and adapted them into these machines. These mecha have been designed specifically for you—fluid, agile, and built for close-quarters combat."

Joy folded her arms, nodding in approval. "Fantastic."

Glassman continued, motioning toward the blueprints displayed on a nearby monitor. "We've also integrated energy shields into the design. They'll protect you from projectile fire, but like your personal shields, they have a limit. Once depleted, they'll need time to recharge. Be mindful of your shield levels in battle."

Frederic exchanged a glance with his teammates before nodding. "Understood. We've dealt with similar shield mechanics before. We'll keep an eye on them."

A satisfied smile crossed Glassman's face. "Good. Now then, allow me to introduce you to your mecha."

With a dramatic sweep of his arm, he gestured toward the four towering war machines. Each stood tall and imposing, their designs reminiscent of the Spartans' own armor suits—sleek, powerful, and built for war.

The Spartans took a moment to admire the craftsmanship. The sheer scale of the mecha, combined with their familiar yet enhanced design, sent a surge of anticipation through them.

Dr. Henry Glassman gestured toward the towering mecha standing before them, his voice brimming with enthusiasm. "What do you think? These models are essentially based on the Gundams the Federation has been building since the war began. We've reinforced them with superior armor, utilizing materials borrowed from the Terran Dominion."

Linda let out a low whistle as she examined her own Spartan-inspired mecha, its sleek yet formidable design capturing her attention. "I'm impressed. It looks great."

"It's surreal seeing models of ourselves like this," Kelly added, taking in the sheer detail of the mechanical giants.

Linda smirked, resting a hand on her hip. "I'm confident I'll perform even better once I'm inside that thing."

Frederic chuckled. "Just make sure you stay safe while piloting it."

"I'll do my best to stay alive," Linda shot back with a confident grin.

Master Chief turned to Glassman. "Are there weapons available?"

Glassman nodded eagerly. "Absolutely! We've outfitted them with weapons based on standard infantry loadouts. On top of that, we've integrated plasma technology—some of Covenant or Banished origin, and even a few advancements from Forerunner systems."

He paused for effect before adding, "We've also developed a plasma beam rifle capable of taking down a mobile suit in a single shot."

Frederic raised an eyebrow. "Are you serious?"

"Absolutely," Glassman confirmed. "The concept was developed by Dr. Halsey and Dr. Liang from GDI."

Master Chief considered this for a moment. "Can the mecha be installed with an AI for autonomous operation?"

Glassman smiled, clearly anticipating the question. "Yes, indeed. We've integrated AI systems, allowing your trusted AI to take control when you're not piloting it."

Joy shifted uncomfortably but managed a small smile. "I guess that means I'll be fighting alongside you, Chief. Although... I'm not sure if I'm ready for it."

Master Chief placed a reassuring hand on her shoulder. "I believe in you, Joy. You can do this."

Joy's expression softened, his encouragement giving her the confidence she needed. "Thanks, Chief," she said, her voice filled with newfound determination.

Master Chief turned back to Glassman. "So, what's its name?"

Glassman took a deep breath, then proudly declared, "We've named it... the Spartan Sentinel."

...

The Zeon battalion finally reached the enemy's location. Commander Rudolf Butsham stood atop his command vehicle, binoculars raised as he watched his air force advance toward the enemy-held base. Their mission was simple—reclaim what had once belonged to Zeon.

As his bombers soared through the sky, he studied the defensive perimeter below. Tall walls surrounded the territory, reinforced with what seemed to be GDI and UNSC fortifications. A smirk crept across his face.

"So they've built a wall to stop us?" Rudolf scoffed, lowering his binoculars. "Heh, what a joke. They'll be destroyed regardless."

He reached for his radio and gave the order. "This is Commander Rudolf Butsham. Bomb that area. Let the enemy feel the might of Zeon."

"Yes, sir! Bombers are en route!" came the swift response from his officer.

The formation of Zeon bombers adjusted course, preparing to unleash devastation upon the enemy stronghold. But as they neared their target, sudden bursts of anti-air fire erupted from the ground. Missile barrages, railgun rounds, and precision sniper shots struck the aircraft one by one. Explosions filled the sky as the bombers were gunned down before they could release their payloads.

Rudolf's smirk vanished. "What!?" He barely had time to process the disaster before an even deadlier response followed.

A storm of bullets, plasma bolts, and laser fire rained down upon his battalion. Explosions rocked the battlefield as Zeon soldiers scrambled for cover.

"Take cover!" Rudolf roared, diving behind an armored personnel carrier as enemy rockets soared through the air. Several of his men weren't as fortunate, torn apart by relentless firepower. Their vehicles, once a symbol of Zeon's dominance, were now burning wrecks littering the field.

On the opposing side, UCA forces and Rhodope militia fighters unleashed a devastating counteroffensive. GDI and UNSC snipers picked off Zeon officers with pinpoint accuracy, while Protoss Spearhunters wielded prismatic disruptor rifles, slicing through enemy ranks from afar. The Rhodope militias, armed with whatever weapons they could find, fought fiercely alongside their allies, determined to repel the invaders.

Amidst the chaos, Rudolf barely escaped death. He leaped from his APC an instant before a rocket struck, sending a fiery explosion into the sky. Landing hard, he rolled behind the wreckage of two colliding APCs and immediately barked orders into his radio.

"Send in the mobile suits! Crush them!"

"Yes, sir!" came the hurried response.

Meanwhile, Zeon troops attempted to push through the dense forest, hoping to flank the enemy. They moved cautiously, unaware that UCA forces had already anticipated their plan.

From the shadows, a voice echoed: "Now!"

The UCA and Rhodope militia launched a surprise attack. GDI Shockwave Troopers stepped forward, unleashing disruptor cannons that disintegrated entire squads of Zeon soldiers. Protoss zealots charged head-on, their psi-blades cutting through armor like paper. Dark Templars flickered in and out of view, appearing only to strike down their foes with ruthless efficiency.

A Rhodope militiaman, gripping a UNSC-provided rocket launcher, took aim and fired—an APC erupted in flames, its crew incinerated. Suddenly, two Dominion Predators lunged out of nowhere, their beast-like forms tearing through the battlefield with terrifying speed. They landed amid a group of stunned Zeon soldiers and unleashed a devastating volley of fire, cutting them down before they could react.

"What the hell!? It's an ambush!" one Zeon soldier screamed.

"Fire! Fire!" another shouted, unloading his rifle at the monstrous Predators.

The bullets merely bounced off the creatures' titanium armor. In the blink of an eye, the Predators lunged forward, their claws ripping through the hapless soldiers.

A Magella Eins tank swiveled its turret, desperately trying to find a target. Before it could fire, a UNSC Railgun Trooper fired a single, precise shot—its armor crumpled inward before the tank detonated, a plume of fire and smoke erupting into the sky.

Nearby, two UNSC Beam Troopers waded into the chaos, their weapons emitting searing beams of energy that vaporized Zeon soldiers where they stood. Rhodope militiamen provided covering fire, ensuring no survivors escaped.

When the dust finally settled, the battlefield was a graveyard of burning wrecks and fallen Zeon soldiers. The remaining survivors, overwhelmed and outgunned, dropped their weapons and surrendered.

...

Across the battlefield, Karra Vastoree, Luna, and their allies clashed with the advancing Zeon troops. The enemy pushed in from the left flank, but their assault was met with relentless fire from GDI watchtowers and Vulcan turrets. Tracer rounds and incendiary blasts lit up the battlefield as Zeon forces struggled to break through the defensive line.

A Magella Attack tank rumbled forward, its main cannon roaring as it fired upon a GDI watchtower. The shot struck its target, but the reinforced structure only suffered minor damage. Before the tank could reload, a GDI Guardian Railgun Cannon locked on, unleashing a devastating beam that tore through the Magella's armor, reducing it to a smoldering wreck.

Meanwhile, Protoss zealots, centurions, and sentinels surged ahead, engaging the enemy infantry in brutal melee combat. Vindicators provided long-range support, unleashing searing energy beams that carved through Zeon vehicles like paper. Amid the chaos, Luna charged into the fray, her AK-47 blazing as she covered Karra Vastoree, who fired precise bursts from his pulse carbine.

As bullets rained down, Luna ducked behind a large rock, her breath ragged. She peeked out just in time to see another Magella Attack tank rolling toward their position.

"Shit! We need something to take down that tank!" she shouted.

Before Karra could respond, four blinding railgun beams streaked through the air, striking the tank in rapid succession. A fiery explosion engulfed the vehicle, sending debris flying. Luna turned to see a squad of GDI Zone Troopers descending from the sky, their jetpacks hissing as they touched down.

"Need some help?" their squad leader called out.

Karra Vastoree smirked. "Your assistance is much appreciated, my friend."

The squad leader wasted no time. "We've spotted more enemy troops inbound. They've got those flying hovercraft bikes for air support. Think you can back us up?"

Luna nodded, gripping her rifle. "Sure thing!"

They pressed forward together. Zone Marines activated their energy shields, deflecting incoming fire before switching to their beam assault rifles, mowing down Zeon soldiers with rapid bursts of searing plasma. In the distance, GDI snipers picked off the Wappa hovercraft squadrons, while Protoss Vindicators focused their pulse beams on a Weasel APC, reducing it to molten scrap.

Luna kept firing until her AK-47 clicked empty. She reached for another magazine—only to find none left.

"Damn! I'm out of ammo!" she growled, frustration tightening her grip.

The Zone Trooper squad leader glanced at her. "Want to use one of ours?"

Luna blinked. "W-What? Are you serious?"

Without hesitation, the trooper handed her a GD2 Kinetic Rifle. It was sleeker, heavier, and far more advanced than the battered AK she had been using.

"I am," he confirmed before rocketing toward the next engagement.

Luna turned the rifle over in her hands, marveling at its futuristic design. But before she could admire it further, gunfire erupted around her. Instinct took over—she spun on her heel and squeezed the trigger. The kinetic rounds tore through the approaching Zeon soldiers, dropping them instantly. The rifle's power was undeniable.

A grin spread across her face. "Oh, I love this gun so much."

...

A squadron of Zaku IIs charged forward on foot, weapons raised as they unleashed a barrage of firepower toward their enemies. Their confidence was unwavering—until something unexpected descended from the sky.

With a thunderous impact, a unit of Spartan Sentinels landed, their towering forms gleaming in the battlefield haze. The Zeon pilots hesitated, stunned by the sheer presence of these unfamiliar mecha.

"What—what kind of mobile suits are those?!" one pilot stammered.

"Look at their design," another whispered, his voice tinged with unease. "They resemble the White Devil..."

A third pilot, more seasoned than the rest, straightened in his cockpit. "Hold your ground!" he barked. "We are Zeon! Proud soldiers fighting for our independence! We crush those who oppose us! Men, engage the enemy!"

Galvanized by his words, the pilots steeled themselves and surged ahead, weapons blazing.

Meanwhile, Master Chief and his Blue Team have finished their simulation training, their new mecha fighters standing at the ready. Exhaling slowly, Chief gave the command.

"Blue Team—engage."

The Spartan Sentinels sprang into action. As the Zakus spread out, attempting to overwhelm them with sheer numbers, Chief found himself flanked by two enemy mobile suits. Gunfire erupted as the Zaku IIs opened fire, but Chief rolled left, narrowly evading their shots. In one fluid motion, he leveled his assault rifle and fired, the rounds punching through the nearest Zaku's armor. It staggered before erupting into a fiery explosion.

The second Zaku II pressed its attack, spraying him with bullets, but Chief's energy shield absorbed the brunt of the assault. With practiced efficiency, he switched to his UNSC-Forerunner beam rifle, took careful aim, and pulled the trigger. A brilliant shot pierced through the enemy mobile suit, detonating its reactor.

Nearby, Frederic met an oncoming Zaku II in close combat, wielding twin dueling energy blades forged by the UNSC. He weaved past incoming strikes, his blades slicing through the enemy mech with deadly precision. The Zaku barely had time to react before it was cleaved in two, its remains collapsing in a blaze of fire and smoke. Another enemy pilot lunged at him with a heat hawk, but Frederic was faster—his shoulder-mounted Spartan laser cannon charged and fired, piercing through the Zaku's chest, sending it to the ground in ruin.

Across the battlefield, Linda and Kelly faced off against a squad of enemy mobile suits. From an elevated position, Linda steadied her beam sniper rifle and fired, her shot ripping through a Zaku's chestplate. The explosion rocked the field as Kelly leapt into action, vaulting high before driving her foot into an enemy's head. The impact sent the Zaku staggering back, giving her just enough time to unload a barrage from her beam assault gun. The enemy never stood a chance.

Three remaining Zakus attempted to divide and conquer, but Linda was already moving. In a single motion, she drew her energy blade and severed the head of one, then turned and impaled another straight through the cockpit, eliminating the pilot instantly. Kelly tackled the last enemy suit to the ground, slamming it down with sheer force before plunging her energy knife into its chest.

A Zaku commander raised his rifle, aiming for Kelly. She didn't hesitate. Before he could fire, her beam assault gun barked, the shot striking true. The commander's mobile suit crumpled as flames erupted from within.

The dust had barely settled when the sound of reinforcements filled the air. GDI and Dominion mecha fighters stormed onto the battlefield, their weapons blazing as they engaged the remaining Zeon forces.

Kelly smirked, lowering her weapon. "Looks like they arrived just in time. No need for us to take on the whole enemy force alone."

A voice crackled over their comms.

"Blue Team, this is Captain Lasky. Do you copy?"

Chief responded immediately. "This is Blue Team. Enemy mobile suits eliminated. Allies engaged."

"Good. New orders: locate and neutralize the enemy's main base. Our forces are mobilizing. Coordinates have been uploaded to your mecha units."

"Understood," Chief confirmed before turning to his team. "Blue Team, new mission. Locate and neutralize the enemy base. Establish a foothold."

"Copy that," Frederic replied.

Joy glanced at the data streaming onto her display. "You think we'll find them easily?"

Chief's voice remained steady. "Only if they find us first. For now, focus on the mission."

"Alright," she nodded.

The Spartan Sentinels took to the skies, their engines roaring as they soared toward their objective. Above them, their allies' air forces and mecha fighters moved in formation, ready to strike. The battle for the Zeon stronghold had only just begun.

...

Rudolf Butsham and his dwindling infantry forces struggled against the relentless assault of the UCA. Their outdated weapons and vehicles proved no match for the enemy's advanced firepower, reinforced armor, and impenetrable defenses. One by one, their tanks were torn apart by concentrated barrages, while their air support never stood a chance—mercilessly cut down before they could make an impact. Even their mobile suits, once symbols of Zeon's strength, faltered against the Spartan Sentinel models. The new mecha moved with uncanny precision, reacting faster than the famed Gundams ever could.

Ducking behind the smoking wreck of a Magella Attack tank, Rudolf fired his sidearm in defiance, squeezing off desperate shots before retreating into cover. Around him, the battlefield was chaos—explosions rocked the ground, the cries of wounded soldiers filling the air.

A frantic voice from his radio snapped his attention back.

"Call for reinforcements! Now!" Rudolf barked, his voice hoarse with frustration.

"I—I'm trying, sir!" the communications officer stammered. "But the radio frequencies are jammed! I can't reach HQ!"

"What?!" Rudolf's grip tightened around his pistol. "Those damn bastards... jamming our communications. How did it come to this?" His rage boiled over, but deep down, he knew—the battle was lost.

Before he could voice another command, the sky darkened with the shadow of approaching gunships. The whine of engines grew louder, and then the unmistakable roar of vulcan cannons filled the air. A pair of GDI Scythe gunships swooped in, their weapons unleashing hell upon the Zeon forces below. Bullets tore through bodies, rockets detonated with merciless precision, and in a matter of seconds, Rudolf and his remaining men were reduced to nothing more than smoldering wreckage.

With their leader dead and their forces decimated, the surviving Zeon soldiers had only one choice—they surrendered. The battle for the region was over, but victory felt hollow. As the UCA forces secured the battlefield, the real fight loomed ahead: the final push to neutralize Zeon's military headquarters.

...

The Blue Team and their allies have reached an enemy location somewhere in the region of Bulgaria. Dominion banshees and GDI MK.VI fighters rain down rockets upon the enemy military, causing destruction to the structures.

Coalition dropships land in the enemy military zone, deploying troops and vehicles to seize control. GDI Atlas Retaliators and Atlas Stormwards target mobile suit mecha hangar bays, preventing enemy pilots from launching their mobile suits. Meanwhile, the Blue Team destroys Zeon vehicles and eliminates enemy barracks. The suddenness and speed of their attack leave the Zeon soldiers shell-shocked.

Coalition infantry forces rush through the area, engaging Zeon soldiers and apprehending those who surrender. Zeon soldiers manned heavy machine gun turrets and open fire, but they are swiftly neutralized by GDI pitbulls and UNSC rocket warthogs. The Zeon airfields are overrun, with Coalition forces preventing Dopp fighters from taking off and forcing surrenders from Zeon pilots and soldiers.

At the Zeon military headquarters, the Blue Team disembarked from their towering Spartan Sentinels, their mechanical frames still humming with residual energy. As Joy remained behind to oversee their mechs, the rest of the team pressed forward, weapons at the ready. Coalition infantry moved in alongside them, sweeping through the structure to eliminate the last remnants of resistance.

Gunfire erupted as Zeon soldiers fought desperately to repel the invaders. Kelly swiftly lobbed a flash grenade into the fray, its blinding burst disorienting the enemy. Taking advantage of the moment, UNSC Marines advanced, cutting down their stunned opponents with ruthless efficiency. The team moved methodically through the corridors, securing each section until they reached the heavily fortified command center—the last line of defense.

Inside, General Canard Suu and his remaining troops prepared for a last stand. Before they could react, a GDI zone marine signaled to a pair of Daelaam dark templars waiting in the shadows. Without hesitation, the templars blinked into the room, their presence heralded by another flash grenade. In the chaos, the psionic warriors struck with blinding speed, their shimmering blades slicing through Zeon troops before they could even raise their weapons.

As the light faded and the gunfire ceased, only one man remained standing—General Canard Suu. Blinded and disoriented, he barely had time to comprehend what had happened before he felt the cold energy of twin psionic blades at his throat. His breath hitched as he finally registered the figures surrounding him. Coalition troops poured into the room, their rifles trained on him, while the Blue Team stood before him, their imposing presence sealing his fate.

Trembling, Canard Suu stammered, "W-Who... who are you people?"

Master Chief stepped forward, his voice calm but unyielding.

"We're the United Coalition Alliance. You are now a prisoner of war. From this point forward, this base belongs to us."

With those words, the UCA claimed victory, securing the Zeon military headquarters and cementing their foothold for future operations. The battle was won—but the war was far from over.