What if Self Insert with Chaos Gacha in Highschool DxD instead FGO
(Kael Rukmono POV - Not Far from Kuoh Town Park)
I adjusted the microscopic earpiece nestled in my ear, pulling my plain grey hoodie tighter around my head. The cool spring air of Kuoh Town was remarkably peaceful, which felt wrong considering the sheer amount of hormonal stupidity and cosmic conflict brewing beneath the surface. My Omni Phone, hidden securely in my pocket, hummed faintly, TB running passive sensor sweeps on all known supernatural signatures in the area.
"Final check, TB," I muttered, my voice barely above a whisper.
"Affirmative, Shikikan," TB's voice, chirped directly into the earpiece. "Target designation 'Fallen Angel A-1' (Raynare) and 'Pawn-Protagonist' (Issei Hyoudou) are approaching the central fountain. All signatures align with known DxD lore."
I sighed, adjusting the scope on my own imaginary weapon. "Can't blame him. It's hard to stay rational in the middle of a literal Harem Anime. Shizu, are you locked on?"
From a safe distance about three city blocks away, nestled high atop the tallest building in Kuoh town
came a single, flat reply.
"Affirmative, Master. Range: 712 meters. Wind factor: negligible. Trajectory stabilized. Weapon System: Railgun Sniper Rifle Mk. II fully charged. Engaging per parameters"
I watched the scene unfold through a pair of miniaturized, enhanced binoculars I had fabricated using the Unknown Dictator. The "date" was reaching its inevitable, cringe-worthy climax. Raynare, looking sweet and innocent in her civilian guise (Yuuma Amano), was leading the poor, horny idiot, Issei, toward the center of the deserted park.
I could practically hear the melodramatic strings playing in the background. Issei was smiling, blissfully unaware that he was about to get a spear of light shoved through his gut.
"This is it, TB," I breathed. "The moment of truth. Let's fast-track this plot point and get out of this cringe-zone."
I watched as Raynare stopped, turning to face Issei under the faint glow of a streetlamp. She opened her mouth, and even from this distance, I could see the false sweetness dissolve into a predatory sneer.
"Would you die for me?"
The infamous line. The starting pistol for the entire DxD plot.
Before Issei could open his mouth to sputter some idiotic, hormonal answer or perhaps a confused 'Huh?' the world was split by a sound that wasn't a crack or a thunderclap, but a sharp, clean Tz-zing!
It was the high-pitched, screaming signature of a tungsten carbide slug accelerated to Mach 7 by magnetic rails, tearing the atmosphere apart.
The Railgun slug, invisible to the naked eye and moving at a velocity that would make even a High-Class Devil weep, struck Raynare with surgical precision.
The visual was immediate and disgusting. One moment, Raynare was sneering, summoning a light spear in her hand; the next, the entire upper third of her head vanished in a pink mist and a shower of dark red, chunky spray. The sheer kinetic inertia from the hit didn't just kill her; it violently spun her body around before slamming it into the park fountain.
The light spear she was conjuring fizzled out into harmless particles. The lights in her eyes both the human disguise and the Fallen Angel underneath, snuffed out instantly.
She collapsed like a broken marionette.
Issei stood there, drenched not in rain, but in the warm, iron-scented vitality of his date. His expression was frozen in a perfect mask of shock, confusion, and primal fear.
"Target 'Fallen Angel A-1' eliminated. Threat neutralized," Shizu's voice reported, perfectly calm, as if she had just finished dusting a shelf rather than liquidating a biblical entity.
I clenched my fist, letting out a relieved breath. "Thank you, Shizu. Another problem solved with the efficiency of Aperture Science and the budget of the Dreadons Chair."
"Should I engage the secondary targets?" Shizu asked.
"Negative," I commanded instantly, pulling my hoodie even further down and starting my retreat. "Do not engage. We only neutralize the primary threat that directly impacts 'Pawn-Protagonist' and avoid all unnecessary plot divergence. If we wipe out the whole Fallen cadre, Kokabiel might accelerate his plans, and I haven't unlocked the BFG-9000 yet."
"Listen up, crew," I said, addressing both AIs and Shizu. "Mission status: COMPLETED. It's time to ghost. TB, pull all sensor logs and mask our energy signatures. Shizu, execute immediate, low-profile extraction from the building. Do not use the flight module unless absolutely necessary; keep it grounded."
"Understood, Shikikan. Initiating full tactical withdrawal," TB responded. "However, warning: High-Energy Devil Signatures detected. Rias Gremory and her Queen are teleporting in. ETA: 15 seconds."
I glanced back at the park one last time. The scene was pure horror: a bewildered teenager covered in viscera standing next to a headless corpse in a fountain that was rapidly turning red.
"They're going to be here in moments," I muttered, quickly melding into the shadows of a nearby alley. I could already feel the slight, subtle shift in the air pressure—the heavy, cloying scent of high-grade demonic power.
"Get out, Shizu. The 'bats' specifically the ones led by the Gremory heir are mobilizing now to investigate. If they find us, we'll have much bigger problems than a messy headshot."
My goal here wasn't to fight a Devil King's sister; it was to preserve my comfortable life. Stealing a major plot device (the Pawn-Protagonist from 'Boobsland') was too much chaos, even for me. We just saved the idiot from the trauma of dying (though replaced it with the trauma of seeing death) and ensured the plot wouldn't collapse entirely. Rias would still find him, likely wipe his memory or recruit him as a witness protection measure.
"Rias Gremory can find her own new slave pawn," I chuckled under my breath, checking my Omni Phone to ensure my electronic footprint was scrubbed. "I'm going home to run a clean-up query and finally install GLaDOS's preferred cable management system."
"Acknowledged, Master. Extraction commenced. Returning to base. ETA: 12 minutes," Shizu confirmed.
"Shikikan," TB chirped, her voice taking on a slightly smug tone. "Initial sensor sweeps indicate the Gremory group has arrived. Rias Gremory appears... highly confused. Audio interception picked up the phrase: 'What in Lucifer's name hit her?'"
I picked up my pace, blending into the evening crowd of salarymen and students. The adrenaline rush was already fading, replaced by the deep, comfortable calm of a job well done.
Chaos begun. Game saved. Now, back to my 100% completion run.