Akira and Akaza stood across from one another, the forest silent but for the people trying to get away from the debris of the wrecked Mugen Train.
Akira and Akaza faced each other, each lowering into their stance. Akira's pose was the iconic Rock Lee stance, one hand forward, knees bent, his body coiled like a spring ready to explode.
Akaza spread his legs slightly, his arms loose yet perfectly aligned with his center of gravity, and spoke in his deep, steady tone:
"Technique Development."
The ground beneath his feet flared red, patterns spiraling outward like cracks in molten rock. The crimson sigils twisted, then cooled into the shape of an intricate blue snowflake.
"Destructive Death: Compass Needle."
The moment the snowflake pattern solidified, in the next instant, Akaza vanished from sight.
"He's fast!" Akira barely tilted his head aside as a fist tore past his face, the air snapping from the force.
Akaza twisted mid-motion and swung a roundhouse kick toward Akira's head, but Akira ducked under it and countered.
"Leaf Hurricane!"
His foot whipped upward in a clean arc, crashing against Akaza's kick. Their blows collided midair. A pulse of wind rippled through the field, knocking both fighters backward. Dirt and gravel scattered as they landed and steadied themselves in perfect sync.
Akaza's eyes gleamed with surprise and excitement. "No human's ever taken my punch head-on before… Impressive. Your name is Akira, right? I'll remember that. My name is Akaza." He grinned wider. "Now, Akira, why don't you become a demon too?"
Akira's reply came flat and calm. "No thanks."
Akaza laughed and rushed at him again. His fist tore through the air like a cannonball, and Akira slipped to the side and counterpunched, but Akaza blocked effortlessly.
"Your form and strength are extremely refined," Akaza said mid-combat, his tone almost admiring. "But you're just a human, with a limited lifetime. You'll grow old. You'll die."
Akira's foot flashed in a counter-kick, which Akaza met with a punch. Sparks scattered in the night as both fighters were pushed apart once more.
"Become a demon, Akira," Akaza pressed. "In a hundred years, no, even two hundred years, if you could continue training endlessly. You could grow infinitely stronger. You could reach the Supreme Realm."
Akira shook his head and said with an unreadable expression. "I don't care about immortality. Everything that exists and everyone who lives will eventually perish. That's something no one can change. Even you, Akaza. No matter how hard you cling to life, you'll die too."
Akaza's expression hardened.
Akira continued with a smirk. "As for your so-called 'Supreme Realm'… I've seen people reach it within their human lifetime. But you've lived for centuries and still haven't. Doesn't that mean your immortality is just… a waste of time?"
Akaza's eyes flared with fury. "Is that so?"
He lunged, his fist snapping toward Akira's skull, only for Akira to block and redirect the blow, countering with a straight punch to Akaza's chest, which he blocked easily.
"If you don't want to become a demon," Akaza snarled, "then I'll just kill you!"
"You can always try," Akira shot back, his leg sweeping upward again in a blur.
Their fists and kicks collided again and again, blurring faster than the eye could follow. The ground trembled beneath the weight of their movements.
Tanjiro, who was watching from the side, could barely breathe. "They're so fast…"
Rengoku, who was resting against a broken train car, narrowed his eyes.
"How is Akira matching that demon in strength…?"
Erika, who is standing nearby, after finishing giving medicine to Tanjiro while tending his injuries, answered quietly, "Akira's always been stronger than normal humans, even when he was little. And his breathing technique amplifies his power even further."
Rengoku turned to her. "His breathing… feels different from ours. What style is that?"
"It's something he created himself," Erika replied. "It's called Star Breathing."
"Star… Breathing?" Tanjiro repeated, stunned.
Erika nodded. "Yes. I don't know much about it, but it increases his physical power to an extremely high level."
Yes, Star Breathing.
That was the name Akira had given to the breathing technique he himself created, a more advanced, evolved form of Sun Breathing.
But unlike the sun that gently nurtured life, Akira's style was modeled after something far more violent and radiant.
It was modelled after a star on the verge of going supernova, which burns with impossible brilliance just before it collapses.
By imitating that celestial fury, Akira could raise his physical strength, speed, and endurance to a level that defied logic, power bursting beyond human boundaries. But in exchange, his body paid the price.
Extreme strain tore at his muscles with each breath.
If a normal person tried to use it, they would die from the strain.
Only Akira could wield it thanks to his superhuman physiology and regeneration allowed him to endure it, and even then, it exhausted him rapidly.
And to make matters worse, Star Breathing was still incomplete; it didn't even have proper forms yet.
For now, Akira was simply using it to enhance his body and fighting purely on instinct and momentum.
BAM! CRACK! THUD!
Akira and Akaza exchanged blows at a blinding pace, fists and legs crashing like thunder. Each impact cracked the ground and shattered the air around them.
But even so, Akira was clearly on the defensive.
Akaza's speed was monstrous, inhumanly fluid, every motion honed by centuries of battle.
"Why do you refuse to become a demon?" Akaza demanded between strikes, his tone somewhere between irritation and pity. "As someone who's mastered the art of hand-to-hand combat, I can't understand you. Only the chosen ones can become demons. For one with such talent to waste away in an unsightly human death… I can't bear to see it."
He lunged forward with a punch so fast it blurred. Akira blocked it, his arms shuddering under the sheer force, and was pushed back several meters.
"Just die, Akira!" Akaza shouted, his voice echoing across the wrecked clearing. "Die while you're still young and strong!"
Akira steadied his stance and rushed forward again, clashing fists with Akaza once more. His eyes burned like violet flames.
"I don't need to live forever," Akira said calmly. "I am a star. All I have to do is burn brighter than anyone else, and one day, when my time comes, I'll go out with a glorious bang the world will never forget!"
He smirked. "A coward's life of hiding in the shadows isn't for me."
Akaza's expression hardened. "Then die!"
He flipped backward into the air, twisting gracefully.
"Destructive Death: Air Type!"
A shockwave erupted as he punched the air, sending invisible blades of compressed force flying toward Akira.
But Akira's Mystic Eyes of Truth gleamed. He could see them, every ripple, every distortion in the air.
He dodged fluidly, flipping backward in rhythm with each invisible strike as the ground where he'd stood exploded in violent bursts of dust and stone.
Then suddenly, Akaza closed the distance, his fist cutting through the smoke, and Akira twisted and countered with a powerful kick.
Their blows met with a thunderous impact, BOOM!
Both fighters were sent flying in opposite directions, Akaza smashing through a row of trees into the forest, Akira crashing into the side of a derailed train car.
For a moment, silence hung in the air.
Then both of them got up, almost simultaneously, their eyes meeting again with renewed fire.
The battle unfolding before their eyes felt unreal.
Even though Akira was clearly holding his ground, it was obvious that Akaza had the advantage; he is faster, sharper, and eerily precise. It was as if the demon could predict every one of Akira's movements before they happened.
Each time Akira tried to counter, Akaza deflected it with minimal effort. It wasn't a fight anymore; it was a storm of motion.
"Can't you see, Akira?" Akaza grinned, his voice echoing over the shattered ground. "Can't you see, Akira? You can't beat me. Become a demon! Join me! We can fight forever and become stronger, without end!"
Akira blinked, then gave him a disgusted look.
"Who the hell wants to spend eternity with you? Go away, you freak."
His exaggerated tone, complete with a scrunched-up face, was so absurd that Erika nearly burst out laughing despite the tension.
Even Akaza froze for a second, unsure whether to be insulted or confused.
Then, without missing a beat, Akira straightened, dusting off his coat and casually said. "Well then… I guess that's enough for a warm-up."
He bent down, completely ignoring the upper-rank demon still standing before him, and reached toward his ankles.
Erika's eyes widened as she realized what he was doing. "Wait… it can't be. Is he really going to…?"
Selena's telepathic voice echoed in her head, calm but amused.
"Yes, Erika-chan. He's really going to do that. He's been wanting to do this his whole life for this moment."
Akira unlatched the metallic cuffs strapped around his ankles, training weights, almost identical to Rock Lee's.
Tanjiro, watching from the side, whispered, "Are those… training weights?"
Rengoku's lips curved in amazement. "He's been training even during battle."
Meanwhile, Akira sent a quick telepathic message to his sister; his calm voice echoed in Selena's mind. "Listen, sister. As soon as I drop them… you know what to do, right?"
Selena replied telepathically, in a serious tone. "Don't worry, brother. I've got you."
Akira stood upright, holding the weights loosely in his hands as he exhaled deeply, the tension in his body shifting. "Sigh… Now I can finally move freely."
And then, Akira dropped the weights.
Akaza smirked, almost amused.
"You think dropping those tiny things is enough to…"
THUD—BOOOOOOOOOOM!
The instant the weights hit the ground, the world shook.
The earth split apart beneath them, exploding in twin bursts of dust and stone. A violent shockwave tore through the field, scattering dust like a storm. When the haze cleared, two deep craters yawned at Akira's feet, smoke rising from the shattered ground.
Even Akaza, Upper Rank Three of the Twelve Kizuki, blinked in brief, unmasked surprise. "…What?"
Akira straightened, a small grin tugging at his lips. "Alright then…" he said, lowering into his stance. "Here I come."
And just then, from nowhere, a triumphant, blazing melody echoed faintly from Akira's system.
[Naruto OST 3 – "Beautiful Green Wild Beast"]
The moment the beat dropped, Akira vanished.
"—!"
Akaza barely registered it before Akira reappeared in front of him, instantaneously, and his fist flashed toward his face. Akaza reacted on instinct, raising an arm to block, but Akira was already gone.
A split-second later, a punch came from his side, and Akaza spun and caught the motion, with a kick, but again, Akira vanished.
A kick came from behind. Akaza twisted to guard, but once again, nothing connected. The air itself screamed with displaced motion.
And then, a punch came directly from the front, but Akaza had no time to react.
BAM!
Akira's fist crashed into Akaza's face, sending the Upper Moon flying through the air like a cannonball.
"IT HIT!" Tanjiro and Inosuke both shouted at once, their eyes wide in disbelief.
Akaza's body tore through the forest, but before he could recover, Akira was already there.
He appeared behind him in a blur, kicking upward with incredible force and sending Akaza spiraling into the sky.
Then, as if gravity itself bowed to him, Akira appeared above the demon mid-air and brought his heel crashing down.
BOOOOOOM!
Akaza slammed into the ground, the impact leaving a crater that swallowed him whole. Dust billowed outward, shaking the surrounding trees.
Akira landed smoothly a few meters away, his breathing steady, his eyes glowing faintly violet. He stared into the cloud of dust where the demon had fallen.
When the haze finally cleared, Akaza was there, kneeling, his body torn and cracked…
But before Akira could speak, the wounds sealed instantly, the demon's flesh stitching back together as if nothing had happened.
Akaza's expression darkened. "Then I'll have to get serious, too."
He sank into his stance, muscles tightening like coiled steel. His voice roared across the clearing.
"Destructive Death!"
Akaza's roar tore through the air as his arms blurred faster than sight.
"Disorder!"
Dozens of punches erupted from him at once, each strike powerful enough to shatter stone. Invisible shockwaves screamed outward, slicing through trees like blades of compressed air, all converging on Akira.