Opening: Distortion by BABYMETAL

Tanjiro, Inosuke, and Zenitsu were following their mentor, Rengoku. There were reports of a demon army gathered nearby and all available members in the Demon Slayer Corps were to mobilize immediately. From what they can tell, they were the closest besides anyone else. They were speeding through a forest path but it would take a bit more time for the others to show up. Knowing this, why don't they wait for the rest of the corps to show up? Wouldn't it be ill-advised to tackle the army head-on with no reinforcements? Rengoku didn't think so.

A Kasugai Crow sweeped down and glided alongside the crew as it stated, "The Hellwalker has engaged the enemy! I repeat! The Hellwalker has engaged the enemy!" The three boys were baffled, even Tanjiro's heart skipped a beat upon hearing this. Zenitsu cried out:

"How?! I thought we were the closest group!" There was no response from the Crow as it soared into the sky and ventured elsewhere. Inosuke was pissed, sprinting even faster as he exclaimed:

"Damn it! There's a whole army of demons for me to kill and he's dining in, first! Hurry up, slowpokes! Lord Inosuke's got places to be!"

Rengoku smiled before exclaiming, "I concur with Boar Boy, how about we pick up the pace?" The three boys sprinted even faster now, doing their best to keep up with their master.

.

.

.

.

.

The Slayer threw a powerful punch that was far too fast for Akaza to dodge as his into a million pieces. The warrior followed up with a gut punch that made his fist shoot through the demon's body, allowing him to split the Upper Moon demon with ease. He tossed the body in front of him and watched as it regenerated instantly. This was an annoying scuffle. Without his nichirin blade, they would both be repeating this cycle endlessly until the sun came up, an outcome he isn't particularly in-favor of. He'd much rather kill the demon with his own hands than wait until the sun came up to do the job.

Akaza smiled, he was in no way intimidated by the hellwalker, the prospect of fighting such a legendary warrior excited him more than anything else. He was incredibly thankful for the fact that the Warrior was without his blade or else this fight would've been over in seconds. The Upper Moon had a unique ability where he could predict his opponent's attacks based on how strong their battle spirit is. The Hellwalker's was strong, unbelievably so. He could see the attacks in his head as clear as day but none of that mattered because he simply couldn't dodge any of it. This man was in a league of his own, far beyond Muzan or any of his other colleagues he's competed against for years. This was an excellent opportunity for the demon to grow stronger and hone his skills.

Akaza spoke up, "You know, I'm enjoying this, I-" The Slayer struck the demon's jaw off with a swift strike followed up with a secondary one that blew the demon's away. The creature landed on his back several meters away as he regenerated and finished his statement, "As I was saying, I'm glad that we're able to fight like this, you and I. No one else quite has the stamina that you do and your strength is astonishing! I truly see why you are the Hellwalker. I thank you for this opportunity to let me improve, I'm looking forward to what I can learn from you."

The Slayer lunged forward and threw a left punch towards Akaza. The demon quickly got on his knees in preparation and miraculously side-stepped the Slayer with his eyes wide in anticipation and shock. He had not believed he'd be able to dodge the Slayer's attack but he was not prepared for the warrior's next one as the Hellwalker grabbed Akaza's face with his right hand to hold him in-place and split him in half with a simple backhand swing from his left arm. The Doom Slayer chucked Akaza's upper torso at the ground as hard as possible, causing it to explode in blood as there was nothing left of the creature's torso but it's insides.

As soon as Akaza began to regenerate, he tried to put some distance between him and the Doom Slayer. However, The demon wasn't fast enough to evade the warrior's next attack as he had his head pummeled in by the Slayer's fist. The warrior kicked the demon just high enough for him to grab both ends of the body. With a tight grasp on the demon's torsos, the Slayer pulled them apart as the insides spilled onto the floor. After this, he smashed the two halves together, squishing Akaza's body like a pancake as the blood splashed all over the warrior's already-stained suit.

He tossed the sandwiched demon in front of him, waiting for it to regenerate so he could continue ripping and tearing. It only took a second for the sandwich to regain its shape with the limbs jutting out with it. Akaza wasn't terrified in the least, in fact, he was enjoying this more than ever. He got back on his feet before springing into the air and assumed a pose as he stated his next attack, "Destructive Death, Air Type," Throwing several consecutive punches directed towards the Slayer. Each attack created a shockwave powerful enough to be launched towards the Slayer like a projectile. It took no time for the projectiles to hit the warrior, but it was about as effective as a rain droplet.

The Hellwalker jumped after Akaza, unleashing several powerful whips of his chain which Akaza barely managed to dodge one before the force of the chain made his body crumble before the Slayer. The warrior rammed through the demon, leaving nothing but a spray of blood to descend to the ground along with him. Once he landed, he turned around to try and destroy the blood that Akaza was about to regenerate from. Unfortunately, he underestimated the Upper Moon's regeneration time as it was faster than everything he's seen thus far. Akaza's body was already restored and kicking into gear.

.

.

.

.

.

The group made it out of the forest and hiked over a steep hill. Rengoku was the first to clear the hill, freezing at the top as he was shocked to see what was on the other side. The other three caught up and their eyes all widened in unison, they were at the verge of throwing up. On the other side of the hill was a field of blood-stained grass. There were noticeable cuts across the landscape as well as random holes. Zenitsu covered his mouth as he said, "W-w-was this the Hellwalker's work…?"

The three boys were terrified of his strength more than ever as they tried to wrap their heads around the fact that one man decimated an entire army. Rengoku's expression was quite serious compared to usual, observing the environment as he commented, "It appears so. Let's get a closer look."

Tanjiro was frozen as he gazed upon the bloody fields the Hellwalker wreaked havoc upon. There was simply no keeping up with the warrior of legend, Rengoku was bullshitting about the ceiling talk before. Even Rengoku was nowhere near as mighty as the Slayer, and they're both better than Tanjiro. How useless is he? He struggles to kill a single demon but the Hellwalker just annihilates an entire army by himself as if it was another walk in the park. Tanjiro could only dream of being that good, much less on Rengoku's level. As impressive as the sight before him was, it was discouraging because it made it clear to him that he doesn't have what it takes to get the job done. He won't be able to take down the likes of Muzan or anyone else. He won't be able to save his sister, all he can do is sit by and watch as the people around him get further ahead.

"Kamado, follow along." Rengoku called out before turning his attention back to the scenery. Tanjiro regained his focus, acknowledging his master's words before chasing after his friends who were already making their way down the hill.

.

.

.

.

.

The Slayer grabbed the demon by the leg, repeatedly spinning in-place to build up momentum before hurling the creature quite a distance away. As Akaza was chucked away, the Slayer prepared his Meathook chain and latched it onto the demon, yanking the back towards him before smashing his fist into Akaza. The Demon's eyes widened in pain before he quickly disintegrated to the might of the Slayer's punch. The Slayer was growing extremely weary from his encounter. He puffed his chest angrily as he was trying to calm himself down. His patience for this fight was growing extremely thin and Akaza's constant banter and taunts were frustrating to listen to.

Once he regenerated, Akaza distanced himself from the Slayer as he regenerated from his previous injuries. The demon found it odd that the Slayer remained stationary and pointed out, "Nice punch! I think my reflexes are getting a little better, what do you think? Sure, you're still hitting me but I'm better able to dodge your attacks a little bit at a time. I'd say a couple more hours of this and I think I'll become an expert at dodging!" Akaza stopped once he noticed the intense growls of the warrior in front of him and commented, "You know, no amount of punching and kicking is going to kill me. If it's any consolation, this is the most fun I've had with a fight in a couple centuries. No one else can quite compare to you, you really do live up to the legend. However, unless you have one of those dinky little blades, you can't kill me but I'm pretty sure you know that."

The Slayer breathed heavily into his helmet due to his frustration. This demon's constant taunting and his inability to kill it was pushing him over the edge. He had enough of it, he inflicted every possible death to Akaza but he still regenerated. A series of violent images flashed in his mind, every way he wanted to kill Akaza played out one by one but none of it would work. He could do it, yes, but there would be no satisfaction because it wouldn't work. He clenched his fist tightly as a headache started to annoy him. He felt sweat on his forehead because his overall body temperature was starting to rise incredibly. On top of that, his heart rate spiked considerably, nearly capping out at 200 beats per minute. He was beyond angry.

Akaza raised his eyebrows out of curiosity as he saw the Hellwalker hunch over, head hanging low. He then noticed something that really caught his attention. Akaza saw things differently, he was able to visualize the battle spirit of the opponents he faced. As a result, he was even able to see the Slayer's which was raging hot like a fire. It was in that moment when the already intense flame of his spirit exploded into an even larger inferno.

264 BPM Track by Mick Gordon

The Slayer whipped his head back as symmetrical, red markings began to cover his body like a tattoo. His muscles expanded greatly, causing them to strain from going past their limit. Akaza's heart stopped in fear as goosebumps overwhelmed his body, causing every strand of hair to stand tall. He choked up, unable to speak or utter a word while his lips trembled and his eyes rattled as gazed into the burning abyss of the Doom Slayer. It was like the sun was directly in front of Akaza, the flames of the Hellwalker's battle spirit were strong enough to even sear the demon. The Slayer was now hunched over, his glowing red eyes locked with Akaza's as the flames of his battle spirit threatened to consume Akaza with his rage. It was like staring into death, itself.

The warrior bent his knees just slightly before vanishing, instantly reappearing before Akaza as if he had teleported. With his fist drawn back, the Slayer threw a ferocious punch towards the demon. Everything was in slow-motion for Akaza, he could see the attack, he could predict it. Every fiber in his body was screaming for him to move and he desperately tried to. However, it was no use. It wasn't that he couldn't, he was simply far too slow.

The Hellwalker smashed his fist into Akaza's head, obliterating it as his movements were fast enough to practically break the sound barrier. The force of his punch created a massive shockwave that blew harshly against the trees. The Slayer proceeded to grab the demon, lifting him up before ripping him in half. In that same instant, he threw the body to the floor and proceeded to pummel it to smithereens. It was like getting hit by a mountain repeatedly. Each punch caused the floor to rumble intensely like an earthquake, only magnified by the repeated flurry of his punches. He wouldn't stop until every single drop of blood was reduced to nothing.

Nearby, the group of Demon Slayer's stopped their movements because an earthquake hit the area. The magnitude of this quake was incredibly high, so much so that the three boys could barely stand on their feet and fell to their knees. Rengoku stood his ground, looking around in a panic as he was trying to understand what was going on. They each had their own way to pinpoint the origin, turning towards the same general direction. Something was going on and they needed to check it out.

The Slayer kept punching the floor, any trace of Akaza he saw was obliterated. He was getting faster, his punches were becoming stronger. Everything became a mesh of colors for the Slayer as his vision was blinded by the repeated swinging of his arm and the dirt lifted from his strikes. He didn't want to stop, he wanted this demon dead. The Slayer dug himself deeper into the ground with each strike, creating a massive crater as a result. The chaos ensued for a little bit longer until the Slayer came to a halt and he allowed the dust to settle.

The warrior found himself inside of a crater that was several dozen meters deep. He sat within the center, panting as he tried to catch his breath. He had never pushed his body that far before in all of his years of fighting. The red markings on the Slayer's body faded away as he was slowly calming down. He didn't know what that was that overcame him, it was like an impulse had taken over, a dormant power he did not know was there. Unfortunately, this surge of power caused his body to go beyond it's already-high limitations which left him writhing in pain at the bottom of the crater. This had never happened to him before. This was also the first time in years since the Hellwalker felt pain of any sort. It's odd that the thing that ended up damaging him more than anything else in his life was himself.

Outside of the crater, a tiny drop of blood had managed to survive the carnage. Fortunately, it was enough for Akaza to regenerate as he was restored back to normal. Akaza didn't bother to move as he lay on the floor, wide-eyed with shock as he stared into the night sky with his mouth half-open. His smile along with his eyes grew larger as a chuckle escaped him. His chuckling slowly transitioned into an insane laughing fit as he was processing what had just happened to him. Akaza raised his voice for the Slayer to hear, "You're fucking insane! Only you are capable of nearly killing a demon with his bare hands! I've never seen that before! It's unheard of and yet you did it!" Akaza leaned forward, looking into the humongous crater as he continued, "Hellwalker, I want to remember you for the rest of my life! You are the greatest opponent I've ever fought! Everything else is nothing but weak trash! I want to keep on fighting, fighting you for the rest of my life. Let us engage in non-stop combat, let us improve each other as we reach new heights, together!"

Akaza got up, his expression made him look like a psychotic maniac as he stared at the Hellwalker. Without any hesitation, he leapt towards the Slayer inside the crater. The warrior did not budge from his position, lifting his head slightly to see the demon approaching him. He didn't flinch even though he was exhausted. As the demon was about to strike the Slayer, something had intercepted Akaza, stopping his attack. Someone passed between them both, surrounded by flames as they sliced off the demon's arm without warning. Akaza backed off right away, keeping his distance from the new challenger.

The person turned around to reveal himself as the Flame Hashira, Rengoku. Akaza was intrigued as he hadn't seen a Flame user before and called out, "And who might you be?" Rengoku replied back:

"That's none of your business, demon. All you need to know is that I'm here to end your life. Now prepare yourself, you're fighting me now."