As the dust clouds cleared, the woman in the red cloak revealed herself: Oda Nobunaga.
Her appearance chilled the air on the battlefield.
Upper Moon Two, Akaza, glanced at her with disgust and turned his back.
"I told you to get lost. I don't fight women. My interest is solely in the strong one, Kyojuro."
Akaza's voice held clear contempt.
To him, who revered strength, women were outside his consideration.
This woman before him wasn't even holding a sword—just a strange iron rod, a matchlock gun.
Such things were useless against demons. No, even if they hit, they'd regenerate instantly; it was the weak's way, relying on tools rather than pure strength.
"Oh? Interesting fellow. Discriminating by gender in the middle of a battlefield."
Nobunaga chuckled softly and slung the matchlock over her shoulder.
"Is this how all demons are? Spouting outdated romanticism. That's why you're relics of a bygone era."
"You seem weak, little girl. Your fighting spirit isn't bad, but you're still just a woman. Crushing a weakling like you won't help me reach the pinnacle of martial arts."
Akaza turned his stance toward Rengoku once more.
A gunshot tore through the air like thunder in a clear sky.
Akaza didn't even react. A mere lead bullet wouldn't pierce his flesh. Even if it did, it'd heal in an instant.
He had fought humans who used guns in this era, so he knew.
The impact struck.
"...?!"
Akaza's eyes widened. The bullet, which should have crumpled, pierced his steel-like shoulder muscle as if it were tofu.
It wasn't a simple puncture. The cells where the bullet grazed screamed in agony.
A sizzling sound echoed.
"Guh...! What is this attack?!"
Akaza clutched his shoulder and hastily retreated. The wound was being consumed by intense heat.
The demon's signature hyper-regeneration didn't kick in. No, the cells trying to gather and regenerate were necrotizing from the energy imbued in the bullet.
"Hey, fighting demon. Aren't you too confident in your Mystery?"
Nobunaga blew on the acrid gunpowder smoke rising from the barrel and smirked coldly.
"My bullets pierce deeper the thicker the Mystery, the more inhuman you are. For a demon like you, it's like poison. That's the principle of Tenkafubu."
"You bitch...!!"
Akaza's face twisted in rage. Nobunaga's strike was so insulting and lethal that it shook his conviction not to hit women.
Above all, the wound that refused to heal properly sent a warning to his instincts.
"Fine. I'll make an exception for you. I acknowledge you."
Thud!
Akaza stomped the ground, and a snowflake-shaped domain expanded beneath him.
[Technique Deployment: Destructive Kill: Compass Needle]
"No matter where you attack from, that attack will never reach me now!"
[Destructive Kill: Chaos Style!!]
Akaza charged at invisible speed. As he threw a punch, compressed air became a shockwave, engulfing Nobunaga.
Power enough to turn rock to dust—a barrage even Rengoku struggled to block.
But Nobunaga didn't evade. No, she didn't even seem inclined to move.
With a languid expression, she flicked her finger in the air.
Click.
In that moment, there was fire. Dozens, hundreds, no, thousands of matchlock guns opened portals in the air and revealed themselves.
"Demon King's Roaring Descent. The Demon Lord's triple-barreled cannons are like this."
[Three Thousand Worlds]
The countless gun barrels, arrayed in a dome around Nobunaga, all aimed at Akaza simultaneously.
Ratatatatatatatang!!!
The gates of hell opened. Before Akaza's fist could connect, a storm of anti-Mystery bullets poured down like rain.
"Gyaaah!!"
Akaza's shockwave was pierced and dissipated by the bullet storm. His fist, his forearm, his chest, his thigh—all were relentlessly punctured.
Thud! Smack! Crack! Bang!
"T-this... this isn't real strength...!"
Akaza was horrified. The Compass Needle was reacting. Killing intent poured from all directions, 360 degrees.
There was no escape. If he tried to regenerate, he was pierced again; if he tried to dodge, the bullets chased him like homing missiles.
"Graaah!! [Destructive Kill: Leg Style: Flowing Flash Swarm Light]!"
Akaza tried to deflect the bullets with kicks tracing trajectories, high-speed kicks accompanied by shockwaves.
But Nobunaga's bullets were the innovation's iron cannons that pierced Mystery.
The moment Akaza's leg met a bullet, it shattered to the bone and flew off.
"Khh...!"
Akaza knelt, his body a mess. The word "honeycomb" wasn't enough to describe it.
Smoke rose from his entire body, and his regeneration speed slowed markedly.
"Why so? You spoke of the pinnacle of martial arts, yet you kneel before mere lead bullets?"
Nobunaga sat on one of the guns floating in the air, sneering.
"Times have changed, you monster. The era of fighting with swords and fists is over. Now it's firepower."
Oda Nobunaga, the revolutionary hero who commanded the realm during the Warring States period.
She quickly embraced the changes of the times, adopting advanced culture and even using foreign slaves as firearms.
As an innovator, unlike the stubborn people of her era, she rode the tide of change and transformed countless things, a figure of greatness.
"I... can't accept this..."
Akaza rose, spitting blood. His eyes were bloodshot.
He couldn't die like this. Not useless to Muzan, not dying meaninglessly to an unknown woman's bullets.
He burned all his life force to prepare a final strike.
"[Destructive Kill: End Style: Blue Silver Chaotic Remnant Light]!!"
Blue fighting spirit exploded from Akaza's entire body. An omnidirectional area-of-effect attack capable of devastating the surroundings.
It was a desperate blow meant to kill Nobunaga, piercing through even hundreds of bullets.
"Oh? Not bad. That fighting spirit, I'll praise it."
Nobunaga's expression turned serious for the first time. She stood up.
"But, it won't reach. Gods, Buddhas, demons... all are just ash before me."
A crimson-black aura surged behind Nobunaga. Space tore apart, and a massive skeletal figure manifested.
A giant black skull wreathed in burning flames.
"Noble Phantasm, release."
It was a flame that even incinerated gods. A Reality Marble that demonstrated what superheated hell was, a great anti-divine Noble Phantasm.
"This is the karmic fire that burns Mystery. The power of me, the enemy of Buddhism, the Demon King."
[Sixth Heaven Demon King Papiyas]
The heat compressed in her palm was like the surface of the sun.
To humans, it was just hot sauna-like warmth or flames, but to demons, who were Mystery itself, it was the karmic fire of hell.
"Vanish, fighting demon."
Kwaaaaaaaang!!!
With Nobunaga's shout, the flames of destruction poured toward Akaza. Akaza's ultimate technique, Blue Silver Chaotic Remnant Light, collided with the Demon King's flames.
Sizzle! Whoosh!
But the outcome was instant. Akaza's blue fighting spirit evaporated the moment it touched the crimson karmic fire. Before the power that negated Mystery, the Blood Demon Art was powerless.
"Ah... aah...!!"
Akaza saw it. His fist, his arm, his torso disappearing like dust in the flames. Overwhelming annihilation where not even pain could be felt.
Not a single cell remained to regenerate; his very existence was being erased from the world.
'Strong... this woman... is strong...'
His final instinct as a fighting demon paid her respect. And Akaza was completely annihilated.
As he vanished, what did he see? Did he see his life flash before his eyes?
Or.
Was it the image of the woman he loved, who had stayed by his side for centuries as he lost his purpose and pursued strength aimlessly?
In the all-consuming flames, he shed a single tear.
The final moment of the fighting god who could protect nothing was seen only by the Demon King.
The battle was over.
In the raging flames, no trace of Akaza could be found.
All that remained was the charred black earth and Nobunaga, still radiating heat.
She released her Noble Phantasm before her clothes could burn completely.
She slowly descended to the ground. She casually discarded her burnt cloak, which dissolved into particles of magical energy. She gazed at Rengoku and Tanjiro, who stood dumbfounded.
"Th-thank you... for saving us! Mhm!"
Rengoku, dragging his wounded body, shouted vigorously.
One of his eyes was closed, but his voice was strong. Tanjiro couldn't close his mouth as he looked up at her.
The power to incinerate an Upper Moon demon—Upper Moon Two, at that—alone and without a single injury. An existence far surpassing the common sense of the Demon Slayer Corps.
"Who... are you...?"
Tanjiro asked in a trembling voice. He could tell by the smell.
She was human, but beyond human.
No, she smelled human but was subtly different.
"Me? Hmm~ I see. Is it introduction time?"
Nobunaga fluttered her regenerated red cloak and introduced herself arrogantly and boldly.
"I am Oda Nobunaga. In the past, I was the Sixth Heaven Demon King who cried out 'Tenkafubu' and sought to unify Japan."
"O-Oda Nobunaga?! But how? You're from the Warring States period!"
"The Hegemon of the Warring States period! Unbelievable!"
Tanjiro and Rengoku were astonished.
A historical figure from hundreds of years ago stood before them.
"Whether you believe it or not is your freedom. However, I am no longer the hegemon of that era."
Nobunaga's gaze softened, but with a deeper, more affectionate look.
"Now, I am merely a vassal following one man."
"... Akatsuki Trading Company."
Tanjiro recalled the scent that flashed in his mind. He faintly sensed that smell from the three demons who attacked Tamayo's mansion.
"Remember this, kids. The true king who rules the darkness of this world and can destroy demons lies elsewhere."
Nobunaga grinned and pointed to the sky.
"You got lucky today. My master ordered me to spare your lives. Get stronger. That way, my master will be pleased."
She finished speaking and hopped onto her matchlock.
"Wait! That person's name...!"
Tanjiro shouted, but Nobunaga vanished without looking back.
Left behind, Rengoku and Tanjiro gazed at the burnt forest and the sky brightening with dawn.
They sensed it. Beyond the fight with demons, a larger, unknown force was at work.
A massive wave of a new era was rising like the smoke of the Infinite Train.
And.
"What the hell, why is this guy a woman now?"
"Ah, is it you? The one who guided me to my new master?"
Nobunaga met the resurrected Enmu in the forest. She was dumbfounded by Enmu's appearance.
[Hey, Master.]
She immediately sent a magical communication.
[What?]
[Why is Enmu a woman now? Can you control that now?]
[Ah~ I did that on purpose. If left as a man, he's just a creepy pervert, right?]
[Ah~ Well, if a woman does perverted things, it's more tolerable. I'll allow it.]
Knowing Enmu's personality, Akira thought it'd be less off-putting if he were female, so he intentionally changed the gender.
[More importantly, return quickly. It's almost time to head to the Infinity Castle. With Akaza's death, of all people, Muzan will likely summon an emergency gathering in anger.]
And so, the curtain was finally rising on the grand finale.
Infinity Castle.
The time had come to usurp it.