Within the empty circle, two streams of light—one bluish-green, the other crimson—collided, separated, and clashed again in a frenzy.
Every exchange came with a piercing metallic hum.
The shockwaves they kicked up cracked the ground below into countless fractures, sending pieces of rubble flying into the air before they rained back down.
Rip!
Shinichi slid low across the ground, and at the same time, his blade swung faster and faster.
The Transparent World had raised Shinichi's perception to a level he had never reached before.
He could "see" the trajectory of every thorn whip Shōkyū released.
He could "predict" the angle of each attack, and he could even clearly make out the flow of that strange power inside Shōkyū's body.
And with the enhancement of Life Breathing, Shinichi's strength, speed, and reflexes had all been pushed to their absolute limit.
Every swing of his sword seemed ordinary, but its power was dozens of times stronger than Forest Breathing.
On the battlefield, the demons Shōkyū had summoned were extremely troublesome.
Aside from the massive number of ordinary demons, there were also some powerful demons mixed in among them, demons on the level of the Lower Ranks.
They had been called out from Yomi, and to the members of the Demon Slayer Corps, these Lower Rank-level demons were a tremendous threat.
Since the battle had broken out, more than a dozen Demon Slayers had already been slaughtered by them.
But threat was relative.
A demon suddenly lunged at Shinichi from the side. Its body was larger than the other demons, its face marked with eerie black patterns, while several tough, rope-like serpents extended from its back.
It was none other than Rokuro, one of the former Twelve Kizuki, and also the first Lower Rank demon Shinichi had ever faced.
Back then, Rokuro had pushed Shinichi through a bitter, exhausting fight before he finally managed to deal with him.
But now, Shinichi did not even spare him a proper glance. His blade merely turned, and a streak of bluish-green sword light swept past.
Rokuro's body froze in midair.
His eyes widened, and strange, clicking sounds came from his throat.
Then, from his forehead down to his chin, a thin line of blood appeared.
In the next instant, Rokuro's body split cleanly down the middle and fell into two halves.
It did not end there.
Another demon crawled out of a crack behind Shinichi.
Several drums were embedded in its body, and strange runes were carved across the drum surfaces.
Shinichi's blade light swept out again, so silently it made almost no sound at all.
Kyogai, the former Lower Rank demon, had his neck cut through.
One after another, the Lower Rank demons who had forced the Demon Slayer Corps to pay such a terrible price fell beneath Shinichi's blade like paper figures.
His sword was too fast!
So fast that not a single Lower Rank demon could withstand even one exchange.
"Not bad, not bad! You're even stronger than I imagined!"
Shōkyū's voice rang out in the middle of their battle, carrying a trace of mockery.
"But does it matter, Shinichi?"
As he spoke, Shinichi's blade cut a wound into Shōkyū's body so deep that bone could be seen. Crimson blood gushed out.
But in the next second, that wound healed at a speed visible to the naked eye, as if it had never existed.
Shōkyū's claws tore toward Shinichi's chest.
Shinichi turned aside to dodge, then cut off Shōkyū's arm with a backhanded slash.
The severed arm fell to the ground and melted into a puddle of blood, but before the broken limb had even fully disappeared, a new arm had already grown from Shōkyū's shoulder.
Shinichi's brows furrowed slightly.
He had clearly mixed the power of Life Breathing into his attacks.
By all logic, it should have countered the power of Yomi inside Shōkyū.
So why?
He had even cut through Shōkyū's neck several times just now!
"Surprised? Did you think that understanding Life Breathing would be enough to deal with me? How naive. Moriki Shunichi's betrayal back then made me cautious. How could I possibly allow something like Life Breathing to become a threat to me?"
Shōkyū grinned, as if he had seen through Shinichi's thoughts. His crimson eyes were full of smug satisfaction.
"My body doesn't only contain the power of Yomi. It also contains Muzan's flesh! On top of that, I have combined it with centuries of Tamayo's research. So what if your blade is fast? What can you do? You can't kill me! You will never be able to kill me!"
As he spoke, Shōkyū spread his arms wide, and the thorn whips behind him poured down like a storm.
Shinichi swung his sword to block.
Bluish-green blade light formed a tight barrier in front of him, cutting down the thorn whips one after another.
But every time one whip was cut apart, two more grew in its place.
Shōkyū's attacks came without pause, as if there would never be an end.
Shinichi's heart gradually grew tense.
His blade was still fast. Every strike was precise and fatal.
But his stamina would run out.
Shōkyū never seemed to tire.
His strength did not weaken. His wounds did not remain. His vitality was like a boundless sea, and no matter how Shinichi slashed at him, he could not reach the bottom.
"It's useless!"
Shōkyū suddenly swung his hand, and a blood-red thorn whip shot out from his palm, hurtling straight toward Shinichi.
Shinichi's pupils shrank. He twisted aside at the absolute limit, and the thorn whip scraped past his shoulder before stabbing deep into the wall behind him.
A wound was left on his shoulder as well.
The power of Life Breathing surged toward the injury, but its healing was unusually slow.
"Do you see it now?"
Shōkyū's voice was full of mockery.
"Your power is useless against me."
Shinichi did not answer.
He simply tightened his grip on his sword and charged forward again.
Blade light and thorn whips collided once more.
Bluish-green and crimson intertwined, turning into an endless tug-of-war.
"Useless! Useless!"
Shōkyū laughed wildly as his claws raked viciously toward Shinichi's throat.
"You can't kill me at all! You can't even hurt me!"
Shinichi leaned back to avoid the attack, then flicked his blade upward and cut off Shōkyū's wrist.
The severed hand hit the ground and melted into blood, but a new hand had already grown out.
Shinichi gritted his teeth and kicked Shōkyū hard in the chest, using the force to retreat and open up some distance.
"Give up, Shinichi."
Shōkyū flexed his newly grown wrist.
"Your fate has already been decided. After you die and I take full control of Yomi, I'll remember you fondly."
"Give up?"
Shinichi raised his head. Shōkyū's smug face was reflected in his black eyes, and he let out a cold laugh.
"Why would I give up? Like you said, if you want to control Yomi, you have to kill me first."
Shōkyū's smile froze slightly.
"And besides, I can see your heart."
Shinichi's voice stayed calm as he continued.
"Those hearts of yours are beating like mad. It isn't just excitement from trying to control Yomi. There's fear too, isn't there? Don't deny it. You're afraid. I can sense it."
"I'll admit it. Your regeneration, your stamina, your power of Yomi—all of them are stronger than mine. But!"
He tightened his grip on his sword, and bluish-green light flared along the blade.
"Fear means you have a weakness. It means you can be killed, doesn't it?"
Shōkyū's face darkened.
"Arrogant brat. Pointless nonsense won't help you! What do you think you can do?"
There was a trace of anger in his voice.
"How would I know without trying?"
Shinichi smiled faintly.
The moment his words fell, he charged out again.
Bluish-green blade light erupted in the darkness. Shōkyū roared, and countless thorn whips shot madly toward Shinichi.
The two collided again.
Blade light and thorn whips intertwined. Bluish-green and crimson crashed against each other.
Every impact unleashed a terrifying shockwave, further destroying the surrounding ruins.
At the same time, outside the empty circle, the battle was just as fierce.
Tengen Uzui and Giyu Tomioka stood back-to-back, their blade lights crossing as they cut down every demon that tried to approach the empty circle.
Both of them were wounded, and both were nearly out of stamina, but their blades were still as fast as lightning.
"How's Shinichi doing over there?"
Tengen panted heavily as he cut down the demon in front of him.
"Still fighting," Giyu said, his voice as cool as ever, though it carried a trace of worry. "That thing's regeneration is too strong. It looks difficult to kill."
"Then what do we do?"
"Believe in Shinichi."
Tengen froze for a moment, then grinned.
"You're right. Believe in him."
The two said nothing more and simply continued swinging their swords.
Farther out, the members of the Demon Slayer Corps were still fighting a bloody battle.
Yet their fighting spirit only burned stronger and stronger.
As demon after demon fell, Demon Slayers also continued to die heroic deaths.
But no one retreated.
No one ran.
"Kill them!"
"For the Demon Slayer Corps!"
"Cut down every demon!"
"The Demon Slayer Corps will never die!"
The shouts of the Demon Slayers outside the empty circle rang out clearly.
And within that circle, Shinichi and Shōkyū's battle remained just as intense.
Blade light and thorn whips kept colliding, bluish-green and crimson weaving together.
Several new wounds had opened on Shinichi's body, and blood had stained his haori red.
Shōkyū's body had also gained several wounds.
But those wounds were healing rapidly.