The world smelled of old paper, cold coffee, and a distinct, metallic tang of sheer exhaustion.He—a nameless male writer in his late twenties—felt the familiar, cold pressure behind his eyes. It wasn't the dull ache of a simple headache; it was the warning sign of a brain that had been pushed past its biological limits for the third consecutive day. He'd been staring at the digital manuscript on his laptop screen, agonizing over the climax of a highly technical military fantasy novel, when the exhaustion finally staged a coup.
He was a master of strategy, capable of mentally coordinating entire fictional armies—flank maneuvers, feigned retreats, artillery concentration—but his body, a flimsy vehicle fueled by instant noodles and caffeine, had no defenses left.
Just one more page. The general needs to secure the flank before the Imperial counter-attack...
A sudden, sharp pain lanced through his skull, so intense it felt like a tactical explosion. The keyboard, still damp from a recent coffee spill, blurred. His hand slid from the mouse, and his consciousness, which had spent years weaving complex tales of war and power, simply flickered out.
There was no white light, no chorus of angels, just a final, absolute darkness—a silence more profound than any defeat on a fictional battlefield.
The silence shattered. It was replaced by the overwhelming, demanding sound of his own cry.
He opened his eyes, except they weren't his eyes. They were wide, weak, and blurry with unbidden tears. A massive, confusing, shadowy figure loomed above him, its face a collection of harsh angles and deep-set crimson eyes. It spoke, but the words were a jumble of low, guttural sounds, entirely foreign to his knowledge of English, Japanese, or any language from his past life.
The world was vast, loud, and utterly terrifying.
He was in a baby's body.
The initial shock was so overwhelming that the strategic, calculating part of his mind—the part that analyzed armies and logistics—shut down entirely. All that remained was pure, helpless panic. He was small, incapable of movement, and completely reliant on the mercy of whatever colossal being held him.
It took weeks for the former writer to regain any semblance of control, months to fully grasp the devastating reality: he had transmigrated. He was now Aeris Vel, a baby girl, abandoned, and currently in the custody of a being that radiated an aura of raw, magical power that felt ancient and utterly dominant.
The environment was unlike anything he had written about. Towers scraped the sky, not with steel, but with smoothly carved obsidian and granite. Distant lights flashed with the sharp, crackling energy of powerful, unfiltered magic. The beings that moved around his colossal caretaker wore uniforms that were rich, dark, and utterly intimidating.
He was in the heart of a city belonging to the Demon Empire. And he, the reincarnated soul, was a human—the weakest, most scorned race in this entire world.
The strategy writer in him finally awoke, his consciousness snapping back into the cold, calculated focus he needed to survive. Mission objective: survival. Threat level: Extreme. Strategy: Absolute secrecy and immediate resource acquisition.
The colossal caretaker was Lord Valerius Kaelen, the Shadow Commander of the Demon Empire.
Valerius was not known for his tenderness. He was a ruthless general whose name was used to frighten misbehaving Angelic children. Yet, it was this fearsome being who had found the abandoned human baby wrapped in tattered rags near the outskirts of his estate and, for reasons Aeris still didn't understand, had taken her in.
He named her Aeris—a Demon word that loosely meant 'the unsettling harmony of light and shadow.'
Valerius never treated her with sentimental affection, but with rigorous, pragmatic training. As soon as she could walk, she was taught the language, the history, and the political necessity of the Lie.
"You are my daughter, Aeris," Valerius would state, his deep voice echoing in the marble halls. "You are blood of the Demon Empire, child of a respected General. Never, under any circumstances, allow your weakness to surface. Your true origin is a weakness that will be exploited, and I will not risk the political stability of my House to save a fool."
He drilled her in rudimentary Demon illusion magic—enough to smooth the texture of her skin, sharpen her features slightly, and disguise her lack of innate demonic aura. The single, small obsidian horn she wore was not real; it was a complex, rune-etched artifact, perfectly fitted to cement her identity as a Demon General's descendant.
The cold, focused persona Aeris wore in public was not a mask she chose; it was the survival uniform sewn for her by the most terrifyingly effective General in the seven empires.
By the age of ten, Aeris was intelligent, strategically minded, and paranoid—the perfect General's heir. But she was still physically weak, and her magic remained frustratingly thin compared to the true Demon children who could shatter stone with a minor spell. She needed power. And then, during a desperate moment in training, it arrived.
Valerius had set her a tactical exercise in the deep, private training grounds of his estate. It wasn't about magic; it was about strategy. She was tasked with breaching a fortified illusionary defensive line guarded by spectral soldiers Valerius had summoned.
Aeris tried everything Valerius had taught her: infiltration, minor illusions, and patience. All failed. The specters were too disciplined, and her energy was too low.
"You fail, child," Valerius's voice boomed from the observation point. "You are too soft. You rely on trickery when true strategy demands decisive action."
The words sliced through Aeris's carefully constructed composure. She wasn't afraid of the specters; she was terrified of disappointing the only person who had ever protected her.
In that moment of immense emotional and strategic pressure, the mental walls that kept her past life separate from her current life buckled. The strategic mind of the nameless writer collided with the historical figure that had occupied his thoughts just before his collapse: Oda Nobunaga, The Demon King.
Aeris didn't scream. She didn't collapse. Her small, ten-year-old body went rigid. Her eyes, usually dark and guarded, gained a terrifying, calculating depth—the cold fire of a revolutionist.
A strange, old voice, authoritative and ringing with a history she didn't know, spoke in the back of her mind: Fools worship tradition. True command is found in the speed and volume of fire.
Aeris raised her hand, her mind instantly calculating ballistics, reload times, and optimal firing arcs—knowledge that had no place in this magical realm. Her own thin human Mana pool was instantly converted into Strategic Energy (SE), a resource that felt sharp, metallic, and utterly precise.
Target locked. Execute Three Thousand Worlds protocol: Phase Alpha.
She didn't summon a fireball or a shadow tendril. Instead, with a sudden, deafening magical crack that echoed the sound of ignition, three flintlock muskets, carved of shimmering black energy and imbued with destructive force, materialized instantly in the air around her.
They weren't aligned for a traditional siege. They were positioned in a quick-fire sequence, targeting the spectral commander's illusionary weak points that her mind, now augmented by Nobunaga, had instantly perceived.
Crack! Crack! CRACK!
The three muskets fired in succession. The spectral shields collapsed instantly, the commander illusion dissolving into smoke. Aeris had breached the line—not with magic, but with superior firepower and flawless tactical execution.
She slumped instantly, the overwhelming rush of SE draining her to exhaustion, but the job was done.
Valerius Kaelen descended from the observation point, his crimson eyes wide with something close to awe. He looked at the smoking remains of the muskets, then at his small, exhausted, human daughter.
"That was not Demon magic, Aeris," he stated, his voice hushed. "That... was something new. Something terrible."
He placed a massive, shadowed hand on her head, not in anger, but in a solemn, protective pact. "Your secret is no longer just your origin, child. It is your power. And this power," he whispered, "will make you either the master of the Seven Empires, or its most hunted prize."
The training became more intense. The disguise became more vital. Aeris, the human girl, was now armed with the mind of Oda Nobunaga, the Demon King.
And at the age of eighteen, she was ready to challenge a world of Dragons and Angels, all while pretending to be one of their own.
Following the terrifying debut of her Strategic Archive, Aeris's childhood ceased to exist entirely. Lord Valerius Kaelen, recognizing the immense, volatile potential of the power, shifted their dynamic from simply a father-daughter relationship to that of a Commander and a Classified Weapon.
Training was no longer about survival; it was about efficiency and control. Valerius, despite his lack of understanding of the "Flintlock" concepts, quickly grasped the strategic utility of the power. He began throwing complex, multi-layered tactical problems at her, forcing the Nobunaga persona to manifest and convert her limited human Mana into devastating Strategic Energy (SE).
"If your enemy relies on brute force, you must shatter their foundation," Valerius instructed one morning, watching Aeris execute a rapid-fire sequence of muskets that obliterated a magically reinforced target. "Your technology is your advantage, Aeris. Their magic is predictable; your bullets are not."
Aeris mastered the conversion of Mana to SE, learning exactly how many seconds she could sustain the power before falling into mental exhaustion. She understood the cruel arithmetic of her power: while a true Demon heir like Malakai could sustain a battle for hours, Aeris had perhaps three focused minutes of maximum output. She had to win—or escape—before the clock ran out.
Her physical body also underwent a transformation. Valerius brought in specialists—sworn to secrecy and often silenced permanently after their work was done—to refine Aeris's movement. She developed a terrifying, focused agility and stealth, skills that compensated for her lack of raw demonic strength. She learned how to move with the coiled, predatory grace expected of the Demon race, practicing the exact angle of her spine and the cold indifference in her gaze until the deception was second nature.
She was no longer just a girl; she was a highly polished, resource-limited weapon designed by the Demon Empire's Shadow Commander himself.
The price of this power and protection was a suffocating isolation. Aeris had no friends. Her existence was a carefully constructed lie that could crumble at any moment.
Her only emotional anchor remained her adoptive father. In the rare moments of downtime, usually late at night in his private study, Valerius would sometimes soften.
"The CA will be treacherous, Aeris," Valerius told her once, tracing the outline of her artificial horn with a massive finger. "The Angelic Heir (AE) will judge you for your darkness, the Draconic Heir (DRE) will mock your lack of innate strength, and the True Demon Heir (DE), Malakai, will despise you for being an outsider."
Aeris nodded, her face blank. "I will be strategically invisible, Father. I will not seek confrontation."
Valerius gave a rare, unsettlingly warm smile. "No. That is the plan of a coward. You will make a noise. You must prove immediately that engaging you is too costly. Do not hide your Nobunaga magic, Aeris. Show them its decisive, terrible power. Make them fear the General's daughter more than they despise her."
His words became her final mandate: Make engaging me too costly.
At the age of eighteen, Aeris was ready. Her application to the Celestial Academy (CA) was a political masterpiece orchestrated by Valerius, leveraging old pacts and veiled threats. It positioned her as a promising, if controversial, entrant from the Demon Empire.
The journey to the CA was an event in itself. The Academy was not built on the ground of any single empire; it was a colossal, flying fortress—an arcane masterpiece that defied physics and served as a neutral zone, suspended high above the central continental plain.
Aeris was transported by a massive, winged Demon warship that broke through the continental cloud layer. When she finally looked out, her breath caught, despite her practiced indifference.
The CA was breathtaking. It was a fusion of architecture: Elven spires, Dwarven forged metal battlements, Angelic white marble towers, all unified by powerful, pulsating magical arrays that kept the entire city afloat. It looked less like a school and more like a captured, aerial kingdom.
A perfect target for artillery concentration, the Nobunaga mind immediately calculated, much to Aeris's silent frustration. Even beautiful things were just potential weak points to her now.
As the warship docked in the Demon sector of the CA's port, the magnitude of her predicament slammed into her. This was the most diverse, condensed population of power on the planet. For the next four years, she would be surrounded by beings who viewed her as prey, a political rival, or—worst of all—a potential threat to their social order.
The first test was the walk from the dock to the Grand Ceremony Hall. The Demon sector was cold, dark, and elegant, but it rapidly transitioned into the neutral zones: areas where Angelic light magic clashed visually with Draconic bronze statues, and where Beastfolk warriors strode past Vampire aristocrats.
Aeris maintained her focused, cold expression, her movements measured and silent. She was a shadow, but she knew the eyes of the Heirs were already on her.
The other Empire successors were already gathering in the Hall, a line-up of breathtaking power and beauty. Aeris cataloged them instantly, the Nobunaga mind assigning threat ratings and weaknesses:
Seraphina Lumen (Angelic Heir): Radiant, almost painfully bright. Threat Rating: High (Pure magical output). Weakness: Predictable reliance on Holy Magic and a perceived moral high ground.
Valeriana Nocturne (Vampire Heir): Alluring, cloaked in shadow and silk. Threat Rating: Extreme (Political and psychological manipulation). Weakness: Vulnerability in direct, rapid-fire conflict.
Lyra Swiftclaw (Beastfolk Heir): Fierce, muscular, radiating primal energy. Threat Rating: High (Physical combat). Weakness: Prone to anger and strategic tunnel vision.
Ignis Scaleheart (Draconic Heir): Towering, with eyes like molten gold, already radiating latent heat. Threat Rating: Critical (Raw, overwhelming force). Weakness: Overconfidence and disdain for 'weaker' magic.
Faelan Whisperwind (Elven Heir): Calm, distant, surrounded by elemental motes of magic. Threat Rating: Medium (Ancient, complex magic). Weakness: Potential lack of urgency in fast-paced conflicts.
Bronwyn Stonehand (Dwarven Heir): Sturdy, focused, her eyes constantly analyzing the magic arrays in the Hall. Threat Rating: Medium (Technological defense). Weakness: Focus on machines may blind her to human strategy.
Aeris placed her own rank: Threat Rating: Low (Perceived). Actual Rating: Highly Volatile.
As she took her designated spot among the representatives of the Demon Empire, Aeris knew her three minutes of effective power were her only chance. She was surrounded by enemies who had centuries of advantage.
Then, the final, and most dangerous, opponent entered the Hall. The arrival of Malakai Shadowbane was less a walk and more a declaration of ownership. Malakai moved with the absolute authority of the True Demon Heir, the scent of ancient shadow magic clinging to her obsidian armor.
Malakai stopped directly in front of Aeris. Her crimson eyes, full of ancestral pride, burned with unconcealed contempt for the low-ranking General's daughter who dared to stand in her space.
"General Kaelen's whelp," Malakai stated, her voice a low, melodic sneer. "I was told the General dared to send a student. I expected... more."
The final confrontation had begun.
Malakai Shadowbane's contempt was palpable, a suffocating wave of pure, aristocratic malice. Her insult, delivered with the low, commanding sneer reserved for disobedient servants, hung heavy in the vast, echoing Grand Ceremony Hall of the CA.
"I expected more," the True Demon Heir repeated, stepping so close to Aeris that their robes almost brushed. "A General's whelp, yet so thin, so quiet. You lack the bloodlust, the raw aura that validates our claim to this institution. If this is the best Lord Kaelen can offer, perhaps the Demon Empire is truly decaying."
The surrounding Heirs—Seraphina, Ignis, Valeriana—watched the exchange with rapt attention, their expressions a carefully calibrated mix of amusement, disdain, and calculated interest. This was the true entrance ceremony: a public test of hierarchy.
Aeris felt the familiar, cold pressure behind her eyes—the signal that the Nobunaga persona was stirring, ready to assert its strategic dominance. She did not allow it to surface yet. A sudden outburst of power would be tactically unsound. She needed to draw Malakai into a favorable engagement.
"An interesting calculation, Princess Malakai," Aeris responded, her voice dangerously smooth and low, laced with the taught arrogance she had learned from Valerius. "To mistake efficiency for decay. My presence here is defined by strategy, not by unnecessary theatrical displays of mass."
The insult landed cleanly. Malakai, with her reliance on centuries of pure, destructive demonic power, valued mass and spectacle above all else. Aeris had just called her strategy inefficient.
Malakai's crimson eyes narrowed into slits. Her tail lashed once, hard, creating a sound like a whip crack against the marble floor.
"Audacity," Malakai hissed. "You mistake clever phrasing for strength. You are an insignificant creature propped up by a General's reputation. Here, only power speaks. And I shall silence your mewling pronouncements with a demonstration of true Demon authority."
Before Aeris could offer a calculating retort, Malakai raised her hand. A swirl of pure shadow magic—deep, absolute, and terrifying—coalesced over her palm. It was a potent, casual display of overwhelming power, designed to make Aeris cower.
"I challenge you, General's Daughter, to a Demon's First Strike before the gathered council," Malakai announced, her voice booming now, staking her claim not just over Aeris, but over the entire Demonstration Hall. "You are a blot on our honor. I shall remove you from this institution before the day is done."
The response from the crowd was a mixture of gasps and murmurs. A formal challenge on the first day was unprecedented.
Aeris's analytical mind went into overdrive. This was too fast, too public. She hadn't finished her survey of the terrain. But retreat was impossible; it would confirm the accusation of weakness and shame Valerius.
Objective: Defeat Malakai decisively without exposing the full extent of the human resource limitations. Strategy: Accept the duel, use the raw power disparity as a tactical funnel, then execute the Nobunaga shock.
Aeris lifted her chin, meeting Malakai's furious gaze with the unnerving, cold focus of the Strategic Archive.
"A duel of power, Princess? Very well," Aeris stated, her voice carrying a cold conviction that stunned even the watching Heirs. "I accept your challenge. But be warned: you will find that strategy, wielded correctly, is a sharper weapon than any raw torrent of darkness."
Malakai gave a short, triumphant laugh. "A pity. You chose your grave quickly."
The officials of the CA were forced to intervene, hastily preparing the Hall's central arena, cloaking it in powerful runic wards designed to contain the magic of the Heirs.
Aeris was given a brief moment of seclusion in a sterile preparation chamber. She ignored the officials' hurried, anxious warnings. She closed her eyes, letting the ambient noise and the adrenaline fade.
In the complete silence of her mind, the Nobunaga Persona fully manifested. It wasn't a voice; it was an influx of cold, logical data. The memory of the writer and the spirit of the Demon King merged into a singular, calculating entity.
$Malakai Shadowbane. Threat Level: Critical. Power Source: True Demon Blood. Weakness: Arrogance, reliance on mass-output, predictable channeling. Terrain Advantage: None. Time Constraint: Three minutes of effective SE.$
Aeris opened her eyes. They were no longer the simple, guarded eyes of a young woman; they were the terrifying, calculating instruments of a military commander. She reached out mentally, accessing the Mana reservoir she had spent years cultivating.
Mana Conversion: Execute.
The Mana flowed not into her hands or her standard Demon illusion runes, but into her core—a sharp, precise conversion that immediately yielded a pool of metallic, vibrant Strategic Energy (SE). It felt like holding the compressed power of a thousand perfectly cast steel bullets.
Weapons Manifestation: Nobunaga's Arsenal. Bayonet Whirlwind and Three Thousand Worlds Volley ready.
Aeris walked back into the arena. Malakai was already there, radiating a fierce impatience, standing in the center of the vast, warded circle. The other six Heirs were watching from the viewing stands—Seraphina worried, Valeriana intrigued, Ignis dismissive.
Aeris stopped at the opposite edge, her posture perfect, her face a mask of cold anticipation.
The official signal was given. The duel began.
Malakai wasted no time on subtlety. She sneered at Aeris's stillness, mistaking it for fear, and raised her hand, summoning a power that shook the very wards of the arena.
"Witness the difference between an appetizer and the Abyss, Aeris!"
A colossal, swirling vortex of Shadowflame erupted from Malakai, pure destructive darkness designed to engulf Aeris completely. It was a spectacular, wasteful demonstration of brute force, consuming immense amounts of Malakai's infinite Demon Mana, but it was impossible for a human to survive. It was a spell of absolute annihilation, moving with the speed of a charging dragon.
The sheer power of the blow sent a massive psychological shockwave through the viewing stands. Even the Angelic wards began to groan under the pressure.
Aeris, however, didn't flinch. She had predicted the strike's predictable center and its wide, inefficient energy consumption.
Target confirmation: Shadowflame front approaching. Execute Defense Protocol: Bayonet Whirlwind.
A massive burst of SE left her core. Instantly, dozens of materialized flintlock rifles sprang into existence around Aeris. Not firing, but spinning—their magical bayonets forming a perfectly symmetrical, defensive, high-velocity cyclone shield.
The Shadowflame hit the Bayonet Whirlwind with the force of an avalanche. Instead of penetrating, the demonic energy was violently deflected and carved apart by the sheer speed and the anti-magic precision of the spinning blades and barrels.
Aeris, utterly untouched, stood serene in the heart of the magical storm, the center of her own protective technology. The Demon Heir's ultimate attack had been neutralized, not by greater power, but by superior engineering and perfect tactical defense.
The crowd was silent, frozen in shock. Malakai's triumphant sneer vanished, replaced by a raw, furious disbelief.