Astra Blaze soared through the neon-lit canyons of Nova City, her Prism Glider a streak of crimson against the twilight sky. Her holo-communicator buzzed, revealing Cygnus Vortex's grim visage. "Astra," he rasped, "we've got a problem. Nebula's back, and she's not alone."Astra's heart hammered. Nebula Vortex, the rogue Prism Centurion with reality-warping powers, was bad enough. But who was her mysterious ally? A holographic map materialized, pinpointing their location – a derelict Xandrosian warship hovering on the outskirts of the city.Landing on the Prism Corps HQ rooftop, Astra found Orion Shield and Aurora Flux already prepping for battle. Orion, with his imposing physique and Celestial Prism, radiated an air of unwavering resolve. Aurora, cloaked in the shimmering energy of the Cosmic Prism, adjusted her helmet. "Looks like Xanathar's finally made his move," Aurora remarked, her voice laced with concern.Suddenly, the warship's hull pulsed with a malevolent energy. A figure materialized on the bridge - Xanathar Prime, his obsidian armor glinting under the neon lights. Beside him stood a cloaked figure shrouded in shadow – a chilling premonition of Nebula's accomplice.Astra activated her comm channel, her voice echoing across the city. "All Denarians and above, report to Sector X-12 immediately! We have a Xandrosian incursion."Across Nova City, Denarians clad in their cobalt battle suits surged into action, their hover bikes zipping towards the designated zone. Millennians, their imposing stature accentuated by their crimson combat suits, manned the city's energy grid, preparing to unleash a devastating counter-attack.As Astra, Orion, and Aurora rocketed towards the warship, the cloaked figure beside Xanathar stepped forward. A ripple of distortion ran through the air, and the figure solidified – a being of pure darkness, its features obscured by an inky shroud. It raised a hand, unleashing a torrent of dark energy that ripped through a nearby building."Behold!" Xanathar boomed, his voice amplified by the warship's speakers. "My new ally, the embodiment of the Null Dimension – Void Reaver!"Astra gritted her teeth. The Null Dimension, a realm devoid of light and energy, had long been a lurking threat. Now, it seemed Xanathar had forged a pact with this terrifying entity.The heroes collided with Xanathar's forces. Orion, fueled by the Celestial Prism, met the Xandrosian warriors head-on, his fists a whirlwind of devastating blows. Aurora, manipulating the fabric of space itself with the Cosmic Prism, created illusions that sowed confusion among the enemy ranks. Astra unleashed a torrent of solar energy, incinerating a group of Xandrosian soldiers.Meanwhile, Void Reaver weaved a dance of destruction. It drained the light from entire buildings, plunging them into an inky blackness. Its mere presence seemed to sap the strength of those around it.A wave of nausea washed over Astra. The combined might of Xanathar, Void Reaver, and Nebula was proving formidable. They needed a strategic advantage, and fast. A voice crackled over her comm. "Astra," Cygnus rasped, panting heavily, "Nebula's using her Quantum powers to teleport reinforcements onto the ship. We're overwhelmed!"Astra knew they had to cut off the head of the snake. With a determined nod to Orion and Aurora, she propelled herself toward the warship's bridge, determined to confront Xanathar and Void Reaver directly.