I nodded to Kenji: "Together, now!" We unleashed DOUBLE SLAYER STYLE: INFINITY SLASH! Our swords danced in perfect sync, cutting through Hellfire Tsunami and Gyutaro's defenses with a ferocity that split the very air, tearing through the thick veil of ash and flame that surrounded us like a suffocating storm. Sparks erupted as our blades struck Gyutaro's scythe, each clash reverberating with a thunderous echo that rippled across the ruined alleyway of District 14, where demon activity had recently surged. Kenji's crimson aura fused with my deep violet, our energies coalescing into a spiraling vortex of raw Slayer power, tearing through the molten ground beneath our feet. The heat from Gyutaro's Hellfire Tsunami should've been unbearable, but our combined technique overwhelmed it with a spectral chill born of centuries-old sword forms passed down by our masters. "He's weakening!" Kenji shouted, sweat streaming down his face, mixing with blood from a gash across his brow. Gyutaro snarled, stumbling back, his form flickering between his demon manifestation and a cracked, more human visage—proof we were breaking his regeneration cycle. "He's vulnerable—Kenji, NOW!" I cried, launching into the final arc of our combo. Kenji mirrored me flawlessly, and our swords became blurs of motion, each strike weaving an invisible tapestry of light and death. At the climax of INFINITY SLASH, we spun mid-air, crossing blades into a glowing X that split Gyutaro's scythe in two, the shockwave sending him crashing into a shattered temple wall behind him. For a moment, silence reigned—then Gyutaro let out a low chuckle, blood pouring from his mouth, eyes burning with hatred. We could end it now—deliver the finishing blow and rid the city of his menace once and for all—but something in his voice stopped us. "Fools," he rasped, coughing, "you've stopped nothing. This city is already infested. I'm just one of many." I exchanged a glance with Kenji. Killing him might bring closure, but what if he was telling the truth? We couldn't risk walking away without answers. "We interrogate him," I said. Kenji frowned but nodded. "Bind him," I instructed, and he used his Spirit Cords to restrain Gyutaro's limbs, pinning him to the scorched ground. "Talk," I demanded, crouching beside him. "How many are here? Where are they?" Gyutaro spat blood, then laughed. "You think they'd tell me everything? I'm not even high enough in the hierarchy to know the full plan. All I know is, there's a Nexus Point beneath this city. A convergence of spiritual leylines. It's being used to summon something bigger—something ancient." My pulse quickened. A Nexus Point? That could explain the spike in demonic activity, the black fog that never seemed to clear, the nightmares citizens had been reporting for weeks. "Where's the Nexus?" I pressed. Gyutaro grinned, teeth stained red. "You're standing above it." The ground beneath us shuddered. A deep rumble echoed from below, and the cobblestones cracked open, revealing a glowing sigil beneath the city—lines of ancient runes pulsing with demonic energy. "Kenji, move!" I shouted as the earth collapsed beneath us, and we fell into darkness. I landed hard, rolling to break the fall, Kenji beside me. We stood in a vast underground chamber, ancient pillars lining the walls, each etched with symbols of sealing and decay. "We need to finish Gyutaro before he can complete any ritual," Kenji said, and we turned to find Gyutaro staggering to his feet. "Too late," he hissed, "you brought me here. To the heart of the Nexus. Your Slayer energy will complete the summoning!" The sigils glowed brighter as if responding to our presence. We couldn't let this happen. Kenji and I launched into the air, activating FINAL FORM: CELESTIAL VOID STRIKE, a move so powerful we had only practiced it in simulations. Our blades were enveloped in pure spirit energy, forming twin crescents of light that dove straight through Gyutaro's chest. His eyes widened, then dimmed as his body dissolved into dust, the demonic energy dissipating like smoke caught in the wind. Silence fell again. No explosions. No catastrophic summoning. Just... stillness. We breathed heavily, our strength nearly gone. "Did we stop it?" Kenji asked, voice hoarse. I was about to answer when the chamber trembled once more—this time softer, but persistent. "No," I said slowly, scanning the symbols around us. "He was telling the truth. He didn't know the full plan. Someone else is behind this." We climbed out of the Nexus chamber and returned to the surface. Dawn had broken over the city, but the air still carried a weight, like an omen. "We need to search for more demons," I said. "If this was only the beginning, we can't wait for them to attack. We strike first." Kenji nodded, already scanning the skyline for movement. We split up, leaping across rooftops, chasing leads, interrogating minor demons who confirmed what Gyutaro hinted at: the hierarchy had shifted. Muzan was gone, but a new order was rising, led by a masked figure known only as The Harbinger. This entity wasn't interested in domination or fear—it sought fusion, the merging of demon and Slayer bloodlines to create a new hybrid race. I reported to HQ, and we were given a list of suspected demon hotspots: a theater in District 7, a collapsed shrine in the Old Quarter, and an abandoned train station where children had recently gone missing. Kenji and I regrouped and headed first to the theater, entering under the cover of night. Inside, mannequins lined the stage, and music played on a loop. Suddenly, the mannequins moved. Possessed. Dozens of puppet demons surged forward. We fought for hours, our blades dulled by the end. The shrine held a different horror—swarms of insect-like demons feeding on residual memories, trying to trap us in illusions. Kenji almost didn't make it out. But the train station was worse. It was a nest. Hundreds of small, child-sized demons crawling the walls, whispering secrets in voices not their own. At the center was a cocoon, pulsing like a heartbeat. "It's a summoning womb," Kenji realized. "The Harbinger is birthing something here." We had no choice. We activated HEART-SUNDERING BLADE: ECLIPSE REQUIEM, pouring our life force into one final technique that scorched the entire station clean. The cocoon burned. The whispers stopped. We collapsed in the rubble, exhausted but alive. Back at HQ, we were hailed as heroes, but we knew better. This wasn't over. Gyutaro was just a scout. The Harbinger's true army hadn't arrived yet. And worst of all, some Slayers had vanished—defected, we were told. But Kenji and I knew the truth. They had been turned. Hybridized. Somewhere out there, our former comrades were becoming something else. We had no time to rest. We sharpened our blades, reinforced our armor, and swore a silent oath. This war would not be won in glory, but in shadows. And we would be the ones to walk that path. Not for fame. Not for vengeance. But because we were the only ones who could.
