A piercing alarm shrieked through Nova City, its crimson glow painting the neon-lit skyscrapers a sinister red. In the heart of the Prism Corps headquarters, Astra Blaze, the Prism Prime, bolted upright in her quarters. Her heart hammered against her ribs, a stark contrast to the usual serenity gifted by the Solar Prism."Intruder alert! Level Alpha!" blared the omnipresent AI, its voice echoing in the sterile white room.Astra wasted no time. Throwing on her holographic interface, she accessed the security feed. A colossal, obsidian ship, unlike anything in their database, loomed over the city. Its hull pulsed with an unnatural darkness, tendrils of inky energy lashing out at the city's energy grid. Power flickered, buildings plunged into darkness, and screams rose from the panicked citizens below."Vega, Cygnus, report!" Astra barked into her comm link."Multiple hostiles detected," came Vega's voice, laced with urgency. "Energy signatures unlike anything I've encountered.""They're bypassing the shields!" Cygnus reported, his voice strained. "They're draining the city's power!"Astra gritted her teeth. This was no ordinary attack. This was a calculated strike aimed at crippling their defenses. But who? And why now?Suddenly, a holographic image flickered to life on her console. A cloaked figure, shrouded in shadow, materialized on the screen. Tendrils of dark energy swirled around them, obscuring their features."Greetings, Prism Corps," the figure rasped, its voice dripping with malice. "I am Nebula Vortex. And your reign of light ends today."Nebula cackled, a sound that sent shivers down Astra's spine. "I've come for the Prism Stones," she continued, her voice turning cold. "Their power will be mine, and with it, the universe!"The image flickered and died. Astra didn't need another word. Nebula Vortex, a rogue Prism Corps member presumed dead for decades, had returned with a vengeance. And her target? The very source of their power, the Prism Stones."Centurions, report to docking bay Alpha!" Astra roared, her voice resonating with authority. "Vega, take point. Cygnus, secure the city. We're taking the fight to her!"Moments later, Astra, clad in her blazing battle suit, stood at the helm of the flagship, the resolute faces of her fellow Centurions mirroring her own determination. Outside, the obsidian ship bristled with weaponry, a chilling premonition of the battle to come."Prism Corps, engage!" Astra commanded, her voice amplified through the ship's speakers. "For Nova City, for the Galactic Council, for the light!"The flagship surged forward, a beacon of hope against the encroaching darkness. Beams of energy erupted from both sides, painting the void in a dazzling display of light and shadow. This was the battle for the future of the universe, and the Prism Corps stood as the last line of defense.