After tending to Astrodog's wounds, Astrocat and Luna prepared to journey to Planet Etherion Prime, where The Void was attempting to seize the Aetherium Nexus artifact. With the information provided by Astrodog, they quickly jumped dimensions, leaving him behind to recover in his spaceship.
Upon their arrival at Planet Etherion Prime, the sight that greeted them was one of devastation. The wreckage of spaceships floated in a sky filled with raging thunderstorms, while the planet's surface stretched out like an endless desert. There was no sign of The Void.
However, before they could search further, the ground suddenly trembled violently. From within the sand, a massive sandworm emerged and instantly swallowed Luna's spaceship. They ran to evade the creature's attack, but more sandworms appeared, surrounding them. Quickly, Luna grabbed Astrocat's hand and used the power of the Zephyr Crest, creating footholds in the air and running at high speed, leaving behind the swarm of sandworms that could not reach them.
They finally landed on the ruins of large boulders, a place that seemed like an ancient, long-lost city. But the danger was far from over. From the shadows of the ruins, an army of Scorpion warriors emerged, surrounding them in overwhelming numbers.
Astrocat drew his sword and unleashed crescent-shaped wind slashes, cutting through some of them. However, the Scorpion warriors' numbers did not dwindle. At that moment, he noticed two shaman-like monsters resembling buffaloes, seemingly summoning more Scorpion warriors. "Luna! That's the source! We have to take them down!" he shouted.
Luna nodded swiftly. She used her wind power again, grabbed Astrocat's hand, and hurled him toward one of the shamans while she dashed toward the other. With incredible speed, Luna unleashed her Light Sword, striking directly at the first shaman's chest, causing it to collapse and die instantly.
Astrocat, thrown toward the second shaman, activated his Celestial Impact technique, creating an energy wave that obliterated the shaman in one lethal blow. As soon as both shamans perished, the entire Scorpion warrior army crumbled, turning into dust.
Amid the ruins, they discovered an ancient altar with inscriptions carved at its base. Light began shooting into the sky, signaling that the artifact had been activated. However, before they could approach, a colossal figure emerged from the altar—Undeath Titan, a giant creature with futuristic technological masks and glowing red eyes, radiating an aura that shook the surrounding ground.
Before they could react, five massive sandworms that had previously attacked them reappeared, encircling them. Astrocat lunged toward Undeath Titan, attempting to strike it with his sword. However, his attack had no effect. Luna tried a Blinding Crescent Slash, but the result was the same—the creature was immune to all their attacks.
As they scrambled for a way to defeat it, the sandworms launched another assault. Luna and Astrocat tried to fend them off, but Luna was struck by a slash from Undeath Titan and was sent flying. Astrocat rushed forward, catching her before she hit the ground.
"Are you okay?" Astrocat asked worriedly.
Luna smiled weakly. "I'm fine, just a little scratched." However, Astrocat noticed part of her clothing torn from the attack. He urged her to rest briefly while he strategized.
Suddenly, the Reliquim Core within Astrocat activated, revealing the weaknesses of the giant sandworms. His eyes widened. "Luna! Their cores are inside their bodies! We have to strike simultaneously!"
Luna, now recovering, quickly stood up. They devised a swift plan. Luna soared into the air, carrying Astrocat with her, then hurled him to the right to eliminate three sandworms while she took care of the remaining two.
Astrocat used his final Chrono Freeze, extending the time-stop duration to 20 seconds. Within that brief window, they simultaneously struck the cores of all the sandworms. This time, they truly perished, unable to regenerate.
However, before they could celebrate, Undeath Titan launched a devastating attack at Astrocat, sending him flying and knocking him unconscious. In his unconscious state, Nyx appeared in his dreams, warning him: "The time is drawing near. A great enemy is coming."
As Astrocat regained consciousness, Luna screamed in panic, "Astrocat! Are you okay?!"
Just then, the Reliquim Core in Astrocat's body activated once more, emitting a faint glow that enveloped him. In an instant, his mind was filled with a stream of data and energy insights that revealed something shocking—Undeath Titan had no physical weak points but was highly vulnerable to light and lightning energy.
Luna noticed the change in Astrocat's expression and asked, "What do you see?"
Astrocat took a deep breath. "This Titan… it cannot be harmed by ordinary attacks. The only way to defeat it is with Lightning Force energy."
Luna fell silent, recalling the words of her fallen mentor: "The only way to defeat Undeath is with Lightning Force."
Astrocat frowned. "I don't have a light element."
Luna gripped her sword tightly. "I do… and I'm willing to sacrifice everything."
Astrocat shook his head firmly. "No! I won't let you sacrifice yourself, Luna! There has to be another way!"
Before Luna could respond, Astrocat's body began to tremble—not out of fear, but from the energy flowing within him. A faint glow radiated from his body, merging with the light emanating from Luna. Their energies began to resonate with each other.
The air around them vibrated, creating a whirlwind of energy that enveloped them in dazzling light. It was as if two long-separated forces had finally reunited. Luna's eyes widened as she felt a warm, familiar energy surge within her, as if her body had been waiting for this moment all along. Astrocat, too, felt something strange yet natural—like destiny had scripted this moment long before they met.
With a look of unwavering determination, they clasped hands, allowing their powers to merge. Lightning and wind swirled around them, forming an energy vortex that expanded, shaking the ground and fracturing the air.
"Let's finish this together!" Luna shouted.
"Together!" Astrocat responded.
In one flawless motion, they shot into the air at an unmatched speed, circling Undeath Titan in a pattern that left trails of lightning. The combination of Luna's holy light and Astrocat's cosmic energy fused into their ultimate attack—Celestial Lightning Burst!
In an instant, Undeath Titan's body was cleaved apart, sacred lightning exploding from within. Its final scream echoed across the sky before its body disintegrated into light, fading into the air. With her last remnants of holy power, Luna raised her sword and unleashed Holy Lightning to purify the monster's soul, ensuring it would never return.
However, before they could retrieve the artifact, a surge of dark magic from The Void struck them, sending Astrocat crashing to the ground.
From the sky, The Void descended, his aura of darkness consuming the stars. The atmosphere around them shifted drastically, as though all life energy was being drained by his presence. His pitch-black glowing eyes locked onto them, filled with the intent to annihilate.
Without warning, The Void raised his hand, and a dense surge of dark magic shot toward Luna. In mere seconds, Astrocat leaped toward her, blocking the attack with his own body. The dark explosion struck him with immense force, hurling him to the ground with a powerful impact. Blood trickled from the corner of his mouth, but he stood firm, staring at The Void with unwavering determination.
The Void smirked coldly. "You are truly persistent. But it all ends here."
With a single gesture, he conjured a massive black orb, its power so dense that the surrounding gravity began to distort. The energy waves from the black orb trembled violently, signifying enough destructive force to annihilate an entire planet.
Astrocat and Luna stared at the orb of devastation in horror. If it were released, there would be no salvation left.
However, just as The Void was about to hurl it, a massive explosion shook the sky. From above, a colossal spaceship sped down at extraordinary velocity, crashing directly into The Void, sending him hurtling into the planet's surface. A deafening boom resounded across the battlefield, unleashing shockwaves that shattered the debris around them.
Astrocat and Luna watched in utter shock as the spaceship, now wrecked from the impact, lay near them, severely damaged from the collision. From the wrecked cockpit, a gravely injured, near-lifeless figure emerged—Astrodog.
Luna immediately rushed to him, supporting his nearly collapsed body. His breath was ragged, blood dripping from numerous open wounds. Burns and slashes marred his armor, nearly destroying it, and one of his eyes was obscured by a streak of blood.
"Astrodog! Hold on!" Luna cried in panic.
Astrodog gave a weak smile, his voice hoarse and trembling. "I… couldn't let you die…"
Astrocat knelt beside him, seeing his friend and rival in such a dire state. Yet, even in his near-death condition, the fire in Astrodog's eyes had not extinguished.
Above them, The Void began to rise from the wreckage, his eyes glowing with deepening rage. Seeing this, Luna tightened her grip on Astrodog's hand, trying to pull him toward the altar where the artifact now radiated brightly.
At the same time, Astrocat struggled to rise, approaching the artifact pulsing with immense energy. As the three of them touched it, a blinding light suddenly erupted from the artifact, engulfing them in a dazzling white radiance.
And in an instant, they vanished from the battlefield… teleported to another dimension.