Akaza vanished from where he stood.
Tanjiro's eyes widened.
Only a blurred blue trail remained in his vision.
The sound of air being forcibly torn apart exploded beside his ears.
Akaza's fist was already bearing down on Rengoku's face.
Rengoku gripped his sword with both hands, sweeping its searing tip diagonally upward into the oncoming fist.
"Flame Breathing, First Form: Unknowing Fire."
The flaming sword slash collided head-on with Destructive Death.
Amid a muffled roar, a violent shock wave rolled outward.
The topsoil of the overgrown field beside the train was ripped up, roots and all.
Stones wrapped in turf struck the steel carriages with a clattering din.
The shock wave pushed Tanjiro backward across the ground.
Inosuke plunged both swords into the dirt and barely managed to steady himself.
On the train roof, Yaha still crouched on the sloping sheet metal.
His eyelids drooped as he watched the red and blue blazes tear into each other below.
Akaza burst into wild laughter.
His fists rained down, giving Rengoku no room to breathe.
"Destructive Death: Air Type."
Invisible air cannons blasted from his fists in rapid succession.
Rengoku swung his sword again and again to block them.
The invisible pressure tore at the flames along his blade like a gale scattering a campfire.
With every blow he blocked, his feet stamped shallow craters into the dirt.
"His punches are so fast." Cold sweat soaked Tanjiro's sword hand.
"He's even scattering Mr. Rengoku's flames."
But to Yaha, the battle moved painfully slowly.
So slowly that he could see the muscle fibers tightening with every punch Akaza threw.
One glance at the snowflake formation beneath those feet told him everything he needed to know.
"He senses his opponent's fighting spirit to predict the path of their attacks."
Yaha gave a soft scoff.
"An instinct like a wild beast's."
He lazily rubbed his knuckles, his gaze filled with the mockery of someone looking down from above.
"Too bad, against a law like me, with no fighting spirit at all-only pure killing intent..."
"This thing is just a worthless piece of junk, blind with its eyes wide open."
Compass Needle worked by reading the flow of an opponent's will to fight.
That logic worked beautifully against Rengoku, because the Flame Hashira's fighting spirit blazed outward, laying every move bare.
But Yaha held nothing at all.
No warmth, no breath. Fighting spirit simply did not exist within him.
If Compass Needle scanned him, it would find nothing but absolute emptiness.
Once Yaha saw through that, he lost even the slightest interest in investigating it further.
Below, the battle was reaching a fever pitch.
Rengoku seized an opening in the gap between Air Type attacks.
His blade flashed.
"Flame Breathing, Third Form: Blazing Universe."
A crimson fire dragon slashed down viciously onto Akaza's right arm.
The arm was severed at the shoulder, exposing charred flesh at the stump.
Tanjiro's eyes lit up.
But that flicker of hope lasted only half a second.
Flesh writhed at the stump of Akaza's severed arm.
In the blink of an eye, a brand-new arm grew back.
Blue demon markings rapidly spread across the fresh skin.
"Do you see, Kyojuro?" Akaza's assault never stopped; it only grew fiercer.
"This is the tragedy of the human body."
Rengoku's breathing grew ragged.
The relentless, high-intensity exchanges rapidly drained even a Hashira's stamina.
An uppercut from Akaza grazed the left side of his forehead.
His skin split, and blood ran down his brow into his eye.
Rengoku shook his head, half his vision stained red.
The next Air Type struck his left ribs with brutal force.
With the dull crack of breaking bones, one side of Rengoku's body buckled.
An alarming trickle of blood spilled from the corner of his mouth.
"You could slash me a hundred times, and I still wouldn't die." Akaza's knuckles bore down again, charged with sick excitement.
"But I only need to land one punch, and you're finished."
Tanjiro shouted and was about to charge in without a thought for the consequences.
Inosuke grabbed him.
Beneath his boar mask, Inosuke's calves trembled faintly.
It was the instinctive fear of a wild animal facing an apex predator.
"Don't get in the way! Against a monster like that, you'd just be throwing your life away, you idiot!" Inosuke snarled through gritted teeth.
On the train roof.
Yaha's gaze settled on Rengoku's sword.
The Flame Hashira panted hard, his left eye caked with blood and his left ribs caved in, swaying on the verge of collapse.
But his grip on his sword never loosened.
With his hand clenched around the hilt, the flames along his blade did not weaken; instead, they burned ever brighter in his desperation.
They lit the bloodstained half of his face a vivid red.
He was staking his life on this.
Preparing to unleash his ultimate technique, trading his life for a chance to stop the monster.
The flames leaped so high they seemed about to melt the night.
Yaha's gaze flicked between the blazing blade and Akaza's fists.
At the edge of his mind, the progress bar that had been stalled for so long lit up.
The unlock condition for [Open (Flame Arrow)] appeared.
[With absolute destructive power, burn straight through the martial faith the target takes pride in.]
What was martial faith?
Akaza's Destructive Death was exactly that.
This martial-arts-obsessed demon had lived for hundreds of years, honing his fists to perfection and treating them as his claim to supremacy over all living beings.
To unlock this fire, Yaha needed an even more overpowering flame.
He had to burn Akaza's Destructive Death and his pride to ash in a head-on clash.
Understood.
The curve of Yaha's lips widened little by little.
He looked down at his right hand.
The ring finger that had twitched throughout the journey stopped spasming entirely.
In its place came an unnatural excitement in the muscles of his arm.
The burning pain deep in his bones turned into intense pleasure.
Sukuna's instincts were taking over this body.
Ancient black cursed markings slithered out from beneath his collar, climbed his neck, crossed his jaw, and covered half his face.
His pitch-black pupils filled completely with savage crimson.
This martial-arts-obsessed demon was at the height of his triumph.
Yaha licked the corner of his mouth.
What he wanted was to grind all of it into the mud at the very moment his opponent's faith burned brightest.
To show this insect what it meant to be crushed by a power on an entirely different plane.
Below, Akaza sensed Rengoku's rising killing intent.
The Flame Hashira's fire gathered at its peak, his blade burning white, his whole body like a stick of dynamite about to explode.
Akaza did not retreat. His entire body trembled with excitement.
He drew back half a step and stamped both feet down.
The snowflake formation beneath him expanded wildly, and his blue demon markings darkened almost to black.
"Good, very good!" He grinned, a scorching hunger burning in his golden eyes.
"Show me your strongest move, Kyojuro!"
He crossed his fists before him, assuming an exceptionally savage opening stance.
Even the surrounding air warped under the pressure.
"Destructive Death: Annihilation Style."
Rengoku moved as well.
He wiped the blood from his face and fixed his gaze on his opponent.
The flames along his blade surged, illuminating the overgrown field as brightly as daylight.
Tanjiro held his breath.
Inosuke tightened his grip on his swords.
Both figures lowered themselves at once, one red and one blue, ready for a charge to the death.
At the instant before they collided.
Yaha's figure became a pitch-black afterimage of cursed energy.
Only a murmur remained in the night wind above the empty train roof.
"Playtime's over."
"Stop being a damn eyesore."
The next second.
Akaza's fist, packed with the full power of Annihilation Style, came within three inches of Rengoku's face.
A pale hand reached out from nowhere.
Its five fingers spread slightly.
Without a single wasted movement, it pressed against those knuckles with utter casualness.
The savage blast of wind from the punch cut off instantly.
A force powerful enough to crush a Hashira's body met what seemed to be an immovable divine mountain.
It failed to stir even the faintest breeze.
Akaza's pupils contracted uncontrollably.
Rengoku's left eye widened, the flames of his blade frozen in midair.
Behind them, Tanjiro and Inosuke forgot to breathe.
The owner of that hand had somehow already stepped between the two fighters.
The wind lifted his black hair, and pitch-black cursed markings covered half his face.
A pair of crimson eyes looked down upon Upper Rank Three.
No warmth, no fighting spirit.
Only a deathly stillness so pure it made the soul tremble.
Yaha tilted his head and spread his lips into a smile of absolute brutality.
"That's a pretty heavy punch."
His fingers tightened slightly, and the sharp sound of grinding bones cracked through the air.
"Too bad you hit the wrong person."
Before you continue