Its name was Rust-Eater.
In this cordoned-off mountain forest, it wasn't among the strongest tier; at least four or five other demons could throw their weight around over its head. But now, those most arrogant demons had already been turned into scraps in the dirt.
Yet, it still stood here, safe and sound. It even dared to appear shamelessly before the members of the Demon Slayer Corps.
What it relied on was its special ability.
[Blood Demon Art: Corrosive Rust]
This was a special power bestowed by the blood of the demons' creator, Muzan Kibutsuji, which evolved and developed as the demon devoured humans and grew in strength. It could instantly corrode the vast majority of metals.
However, it was limited only to metal. It had no special effect on other demons or humans.
But for these swordsmen holding Nichirin Blades, it was an entirely different story. Whenever it wished, the moment a slash struck its body, it could rapidly corrode and rot the weapon away.
A swordsman without a Nichirin Blade—how was that any different from a little kitten without claws and fangs?
"I'll eat you all and then find a chance to escape. I'm certain that Lord will make me one of the Twelve Demon Moons!"
"My ability is the natural nemesis of you brats who use swords."
It lunged forward suddenly. For a moment, it actually forced Kuguruma Natsunishi to protect Yukiziri Sashiko while dodging several steps to the left and right.
"So, you're actually not even an executive-level demon?" Kuguruma Natsunishi asked tentatively. "And who is 'that Lord' anyway?"
What do you mean, not even an executive!
Kuguruma Natsunishi's words struck a nerve. In an instant, Rust-Eater's roaring slashes and scratches became several degrees more ferocious.
"You aren't qualified to know that!"
"Just like those swordsmen before, just stay still and let me eat you!"
The other swordsmen, seeing Kuguruma Natsunishi fall into a "hard fight," swarmed forward to support him. But after the Nichirin Blades of all three were turned into scrap metal, they found themselves in a bind—they could neither continue the attack nor retreat.
"So annoying, you flies."
Seeing that it couldn't take down Kuguruma Natsunishi quickly, Rust-Eater turned its gaze toward the unarmed ordinary swordsmen surrounding it.
Just as it was about to strike, it suffered a heavy blow to the abdomen, nearly having its stomach acid knocked out of it.
"You..."
The incredulous Rust-Eater finally realized that this youth hadn't shown a hint of panic from beginning to end. Even after the weapon he relied on was damaged, his expression remained unchanged.
"I asked you a question. Just answer honestly."
Taking advantage of the enemy curling its body in pain, Kuguruma Natsunishi smoothly followed up with a knee strike. It hit the bridge of the demon's nose directly; a large amount of dark blood sprayed from its nostrils, coating its own face.
With a cry of pain, Rust-Eater's entire vision became blurred. Even after becoming a demon, the pain receptors on the face and the bridge of the nose remained the most sensitive parts.
Before it could recover, it felt its feet leave the ground, and it fell flat on its back.
"Tell me, what are the Twelve Demon Moons? Are they your executives?" Kuguruma Natsunishi asked, having just floored the demon. "And is the ability to rust a katana your unique power, or can the Twelve Demon Moons do this too?"
"..."
Rust-Eater looked at the blurry starlit sky, still failing to process what happened. This was the selection ground for the Demon Slayer Corps. This brat hadn't even become a corps member yet—how could he be so ridiculously strong?
"I'm talking to you."
"I'm going to kill you!"
Rust-Eater struggled to get up, wanting to bite Kuguruma Natsunishi. But before it could even crawl up, it was easily knocked down again.
Even this demon still followed the power mechanics—or rather, the habits—of the human body. Power began from the core and waist, supported by the neck and arms, and finally, the kinetic chain was completed by the hips and lower limbs. This was the complete sequence for standing up.
But for Kuguruma Natsunishi, he only needed to interrupt it.
He kicked its knee directly, then pressed his body weight sideways, concentrating all his strength into his right palm to slam the opponent's head down.
Rust-Eater was pinned back down even faster than it had tried to rise. Its back of the head hit the gravel on the ground with a loud thud. It was a miracle its lights weren't knocked out completely.
The surrounding swordsmen who saw this strike all felt a faint chill at the back of their own heads. This guy is so practiced...
For Kuguruma Natsunishi, this was an instinct almost carved into his muscles. It was just an "Okizume" (pressure on wake-up). It was actually simpler than what he had achieved in other fighting games. After all, in the game he was playing now, there was no "Super Armor" protection when getting up.
"If you talk, maybe I'll let you go, you know?"
Rust-Eater's eyes gradually regained focus. Shame and rage made it almost unable to control itself. It roared, "How could I know something like that!"
Kuguruma Natsunishi: "Then what about your BOSS? You wanted his appreciation just now, so don't say you don't know."
The demon's face stiffened. As if thinking of something terrifying, it instinctively shuddered but continued to be stubborn.
"Stupid brat, even if you kill me, I won't talk!"
"Besides, without a sword, can you even kill me? Hahahaha!"
Hearing this, Kuguruma Natsunishi only let out a slight sigh. He figured if he wanted to extract information, he would probably need some interrogation skills or special items.
Forget it. There would be plenty more demons later. Some information might even be held by the Demon Slayer Corps headquarters and high-ranking officials. Let's push the main quest first.
A fist fell, and this time, there was no holding back. Using the strength boosted in a short time by the Breathing Style, a single punch reduced the demon's face to a bloody mess. Then another punch.
A continuous barrage of fists fell like a rainstorm. Rust-Eater wanted to resist and wanted to get up and run. But whenever it made a slight movement, it would be interrupted by Kuguruma Natsunishi's powerful fists.
For a moment, Rust-Eater had become a drum that couldn't feel pain, pinned to the ground and pounded frantically by Kuguruma Natsunishi.
For Kuguruma Natsunishi, suppressing the demon in front of him was only natural. Setting aside its slightly troublesome Blood Demon Art, its strength was inherently inferior to his own when enhanced by a Breathing Style. And on a technical level, it was a complete idiot. Now that they had entered a ground state, it couldn't even pull off a decent piece of grappling or groundwork. Naturally, it was being completely suppressed.
The game was different. The techniques he had practiced didn't get any special effect bonuses in this game. But martial arts skill and a strong physique were objective realities. Therefore, this was a victory for martial arts.
However, the opponent wasn't just taking a beating; Rust-Eater's mouth was still very tough.
"Stupid brat, you can only act tough for now!"
"Strong? What can being strong do!"
"I am an immortal demon!"
"You can fight now, but can you fight forever?"
"It's still early before sunrise. Do you plan to waste the whole night with me?"
"Just be a good boy and let me eat you. Don't worry, I'll bite your neck off as fast as possible. Am I not merciful? Hahahaha..."
Kuguruma Natsunishi's fists slowed down. "You actually have a bit of a point."
The surrounding swordsmen widened their eyes. One of them even called out, "Brother, don't listen to his nonsense! We'll help you. If we drag it out until sunrise together, this monster is finished!"
Nearby, Yukiziri Sashiko stopped the swordsmen who were about to step forward to help. She said, "Kuguruma Natsunishi-kun knows what he's doing."
"You're the smart one, Yukiziri Sashiko."
The sound of snapping bones rang out in succession. Kuguruma Natsunishi brutally shattered the opponent's four limbs. Then he stood up naturally, picked up the broken blade that was only half its length, and walked to the side of the opponent's head.
"Say, you must have eaten a lot of people, right? After all, your name is so red."
Rust-Eater cried out in startled pain, "Sss... it hurts! What do you want to do?!"
"The sword?"
"Are you stupid? Do you expect that little broken knife to hurt me?"
Kuguruma Natsunishi said expressionlessly, "Have you forgotten? Your hand was severed by me once just now."
Rust-Eater: "Ah?"
Although the sword broke, the fact that it could sever the demon's hand earlier meant that while the rusting speed was fast, it had a limit.
"The slash just needs to be faster than your rusting speed. Right?"
Kuguruma Natsunishi flicked the broken sword in his hand, getting a brief feel for it.
"Besides, so what if the sword is broken..."
[Total Concentration]
In that instant, Kuguruma Natsunishi's energy level began to climb frantically. Among his three attributes, the value for Physique shot up rapidly from 26 all the way to 52.
[Breath of Wind: Fifth Form - Cold Mountain Wind ]
A frost line flashed across, like the chill of late autumn instantly piercing through the mountains. The sharp edge, descending from above, directly tore through Rust-Eater's neck and head.
Kuguruma Natsunishi landed and smoothly sheathed the sword.
"Since when were swords such inconvenient things?"
Immediately afterward, the half-blade of the Nichirin Sword in his hand turned completely to ash.
[Progress: 419/2000 (+156)]
The experience was quite high, but it was a bit hard on the swords.
Looking at the group of stunned swordsmen, Kuguruma Natsunishi called out to them.
"Hey, bring a sword over."
"Shotaro, don't just stand there."
The swordsman named Shota hadn't recovered yet, murmuring, "Is this the wild wind that can tear through evil..."
Only then did Kuguruma Natsunishi realize he had turned off the [Breathing Style Effects]. Could it be that the sword technique he just performed looked too flashy in their eyes even without the effects?
Maybe... I should leave them on from now on.
Kuguruma Natsunishi pondered as Yukiziri Sashiko eventually took a sword from one of the fallen swordsmen and brought it over.
"Kuguruma Natsunishi-kun, please don't be picky."
Kuguruma Natsunishi gave the sword a few spins to get used to it, then slid it into the scabbard. He looked at Yukiziri Sashiko with confusion. Picky about what? Picking up teammates' gear?
Without thinking much, he spoke to the swordsmen who were gradually coming to their senses. "Anyway, the demons are probably mostly killed off."
"Follow me for now. Help me look for any stragglers along the way."
"It's best if not a single one of these demons is left. It would be a waste otherwise."
The swordsmen nodded one after another. One girl even shrunk her neck in fear. This youth's killing intent is so heavy.
"Is there a problem? Say something."
"No... right?"
"This won't count as cheating, will it?"
"It should be fine..."
A few swordsmen showed hesitation.
Kuguruma Natsunishi raised his voice slightly. "A problem?"
Everyone shuddered in unison. Thinking of the hurricane-like force he used to kill the demon, the biting killing intent that wiped out the evil, and... that face that lacked any expression from beginning to end.
Could he be a demonized swordsman whose whole family was killed and sister died tragically, leading him down a path of obsession and revenge? If they refused now, would they be cut down on the spot?
"We'll be in your care!"
The few people actually bowed deeply to Kuguruma Natsunishi in unison.
Good, very spirited... Wait, do I look that much like a villain?
Kuguruma Natsunishi turned his head toward Yukiziri Sashiko in bewilderment. He only saw the young female swordsman tightly covering her mouth, her shoulders trembling as she turned red from holding back laughter.