Tekkai vs Iron Skin

"I am going to kill you, Demon Slayer," the demon declared in anger as he looked at Kyojuro "Though not Hashira, your strength is close to theirs. Perhaps, I will be granted a drop of blood if I slay you both."

The demon could sense that Ryou was the tougher opponent, so he planned to finish Kyojuro first before dealing with Ryou.

"You have to be alive for that to happen," Kyojuro stated before executing his Flame-breathing first form: Unknowing Fire! He dashed toward the demon at incredible speed, ready to unleash a powerful horizontal slash.

Unlike before, the Four-Arm demon didn't wait for Kyojuro to complete his strike.

With a powerful cry, he unleashed his 'Blood Demon Art: Copper Arms'. His once gleaming metallic skin reverted to a normal appearance, but his four arms transformed, gleaming with a copper sheen.

Just a glance was enough for anyone to recognize the extraordinary strength exuded by his arms.

Without delay, he slammed his fists into the ground, creating a deep crater that sent dust and clouds swirling into the air.

The force of the demon's blow shattered the ground like a spider's web, forcing Kyojuro, who had his sword just inches from the demon's neck, to hastily retreat.

"Hahaha... Witness my true strength before you meet your end," the four-arm demon declared, as he charged at Kyojuro with intent to kill.

"Boom!"

As the copper fist of the demon collided with Kyojuro's sword, a resounding sound filled the air, and the overwhelming strength of the demon forced Kyojuro to skid several steps back.

"What strength!" Kyojuro thought.

The clash between them intensified as the Four-Arm demon unleashed its full might, attacking with all four arms relentlessly.

Despite his gutsy attacks, Kyojuro found himself struggling to keep up with the relentless barrage of attacks as time passed. Unlike the demon with limitless strength and inhuman regeneration, he's a mortal.

Exhaustion began to show itself on his face, while his arms grew heavy from the repeated swings of his sword.

Kyojuro panted as his chest heaved with exertion, but he refused to stop his attacks. With a fierce cry and the burning desire to slay the demon, he swung his sword once more.

His attacks weren't without any results, as the demon's regeneration considerably slowed down after repeated damages. Only through consuming human flesh would the demon be able to fully regain its former strength.

Just as Kyojuro prepared for his next strike, Ryou intervened, proposing, "Hey Kyojuro, I know you can still fight, but let me take over. I'm curious to test the demon's strength..."

"Sure," Kyojuro replied, sheathing his sword into its scabbard.

"Ah!" Ryou exclaimed in surprise, then commented, "I thought you wouldn't argue!"

"Though I can still fight, I want to see how you handle the demon and the gap between us!" Kyojuro expressed his thoughts.

"Good," Ryou responded. Kyojuro returned to the injured Demon Slayer's side while Ryou faced the demon.

The Four-arm demon seethed with fury at the sight of Ryou and Kyojuro's actions. It felt as though they regarded him as nothing more than a plaything or a mere whetstone to sharpen their strength upon.

'How dare they?' The demon clenched his fists before charging at Ryou.

Observing the demon's charge, Ryou stood firm without reaching for his sword, intending to confront the demon with his bare hands. It was a move that even fools wouldn't dare attempt when faced with a demon.

"What is he doing?" Kyojuro and the injured demon slayer watched in disbelief, dumbfounded by Ryou's audaciousness.

'Tekkai!' Ryou silently muttered as the demon's barrage of fists struck his chest, triggering a blasting sound accompanied by a slight shockwave.

But to everyone's horror, Ryou stood his ground, merely taking a single step back.

'As expected, the Advanced level Tekkai combined with my physique is formidable,' Ryou thought to himself, 'Now, it's my turn!'

With swift action, Ryou countered the four-arm demon by launching a powerful kick aimed directly at its chest. His Tekkai-enhanced strike connected with the demon's torso with a resounding impact, sending shockwaves rippling through the air.

With a deafening 'boom', the demon was sent flying backward, crashing into one of the nearby retro-style houses with tremendous force.

Under the impact, the entire structure collapsed with the sound of splintering wood while a cloud of dust engulfed the scene.

"Ahhh!" With a fierce roar, the demon emerged from the rubble with a noticeable dent in its chest and blood trickling from the corner of its lips.

Its wound is healing slower than usual, evidence of the energy expended in its prior clash with Kyojuro.

"What are you?" Shin, the Four-arm demon, asked, looking at Ryou with shock.

'A human fighting a demon with bare hands. It's unheard of. Is it Blood Demon Art? But it's impossible since he's not a demon. Is it some kind of special ability?' The Four-arm demon pondered and began to doubt the path he took.

'How can a human possess such power? Why did I become a demon? Wasn't it for its extraordinary power? And now, a human exerts the same skill just like me. Why did I become a demon in the first place?'

Despite its momentary self-doubt, the demon quickly regained its focus. Unlike some demons, it retained its memories after becoming a demon.

Muzan hadn't erased his memories because his ultimate pursuit in life was to become stronger and live long.

"I'm just an ordinary demon slayer," Ryou replied to the demon's question before drawing out his Nichirin sword.

He didn't plan to engage in hand-to-hand combat anymore; after the single exchange, he had gauged the limit of his Tekkai. Now, it was time to kill the demon.

"Nice, Ryou," Kyojuro commented loudly. "I didn't expect him to possess such physical skills. No wonder he's so strong."

'It doesn't matter,' the four-arm demon snapped out of his thoughts and sneered. "Once I kill and consume you, maybe I'll take a step further without his help."

"Then come," Ryou beckoned, his sword pointing toward the demon.