Yaksha demons, kill!!

After brewing a simple cup of tea for Uzumaki Gamu, Tanjiro, and Nezuko, Tamayo said to Uzumaki Gamu, "I'm terribly sorry. The earlier clash damaged the house, so I can't entertain you properly!"

"It's fine. I don't mind!" Uzumaki Gamu replied. Having something to drink was already good enough. Why ask for more?

With that, Uzumaki Gamu lifted his cup and took a sip, then praised her. "It tastes wonderful~ You're very good at brewing tea, Miss Tamayo!"

"...Thank you for the compliment!" Tamayo still couldn't figure out exactly what Uzumaki Gamu was, so she didn't know how to broach a conversation.

Just then, Tanjiro suddenly spoke up. "Um... Mr. Uzumaki Gamu, are you really a ninja?"

"Yes. Most members of our Uzumaki Clan are ninjas," Uzumaki Gamu replied. In short, he continued fooling them with half-truths!

Uzumaki Gamu had chosen to chat with Tamayo and Tanjiro mainly to mooch some food and drink, then see whether he could use Tanjiro to arrange a trade with the Demon Slayer Corps and get a couple of Nichirin Blades!

The earlier fight had given Uzumaki Gamu a sense of the demons' combat abilities. He could easily crush ordinary demons, and stronger ones probably wouldn't amount to much either. Their immortality, however, was genuinely troublesome. He couldn't drag every battle out until dawn, could he? Getting a suitable weapon specifically designed to kill them would make his later battles much easier!

Of course, doing without a Nichirin Blade wasn't impossible. He could try other methods... such as... developing a new ninjutsu?

Tamayo followed up on the topic. "The Uzumaki Clan... I've never heard of you before~"

Uzumaki Gamu smiled and waved a hand. "We're a small clan in the countryside, living a peaceful life cut off from the world~" The Warring States period really was rather rural, so there wasn't anything wrong with saying that!

I see. A hidden family, then? Tamayo had some familiarity with such things.

"Um... Mr. Uzumaki Gamu, why do you kill demons?" Setting aside the whole ninja business, Tanjiro was very curious about why Uzumaki Gamu hunted demons.

"Because I have a commission!" Uzumaki Gamu answered. "We might live in seclusion, but we still come out when we have a mission!" A system mission counted as a commission too, so there was nothing wrong with that statement!

"Your mission is to kill demons?" Tanjiro asked.

"Yes. My primary target is Muzan Kibutsuji... My client believes that he's clung to life for years while committing countless evil deeds, severely upsetting the balance of the human world, so he gave me... Hmm?" Uzumaki Gamu suddenly stopped halfway through.

Huh? Why had he stopped?

Because Uzumaki Gamu had suddenly realized that the lie he'd casually invented made an uncanny amount of sense!

Although the system had given him this mission, the system originated from Yama. And if the mission was to kill demons... these monsters refused to die and kept lingering in the human world, committing all kinds of atrocities. That could very well affect Yama's KPIs, so he gave Uzumaki Gamu a mission to deal with those demons and monsters who refused to die, improving Yama's Hall's KPIs... That idea was perfectly reasonable!

Did I accidentally stumble onto the truth? Maybe Yama's real reason for arranging my reincarnation was to get himself an employee like Black and White Impermanence? If that's the case... I wouldn't mind! If that really was the explanation, Uzumaki Gamu would feel quite reassured~

The earlier explanation-that he'd been granted reincarnation because he'd spent his entire life doing good deeds-had actually left Uzumaki Gamu rather uneasy. That reason was just too far-fetched. It felt like a windfall falling out of the sky, and that wasn't reassuring at all!

If the explanation he'd just thought of was the truth... being forced to work for someone was a little annoying, but at least he was giving something in return. That made it easier to feel at ease!

Seeing Uzumaki Gamu suddenly stop, Tamayo asked curiously, "Mr. Uzumaki Gamu, is something wrong?"

"Well... I just sensed something subtle. That little girl is a demon too, isn't she?" Uzumaki Gamu shifted the subject to Nezuko.

Tanjiro immediately shielded Nezuko and said nervously, "My sister isn't an evil demon! She's never hurt a human!" He couldn't help being nervous. The strength Uzumaki Gamu had displayed earlier was terrifying. Tanjiro's eyes couldn't keep up with him at all, and he could only barely track Uzumaki Gamu's general location by scent. The gap between them was so enormous that even if Uzumaki Gamu chopped Nezuko into mincemeat right in front of him, Tanjiro might not react in time!

To be fair, Tanjiro was probably exaggerating. Uzumaki Gamu shouldn't have been quite that fast!

He could still kill Nezuko, though!

Uzumaki Gamu smiled and waved a hand. "Don't be nervous~ This lady here and that hot-blooded young fellow over there are demons too, and I haven't attacked them. So you don't need to worry about me hurting your sister~"

The lady beside him-Tamayo-asked, "If your mission is to kill demons, Mr. Uzumaki Gamu, why haven't you attacked us?"

"Oh~ I'm only responsible for killing evil demons. This young man's sister and that fellow from earlier-Yushiro-don't harbor any malicious thoughts, so naturally, I won't do anything to them. But... Miss Tamayo, you seem to be carrying some sins, don't you?"

"..." Tamayo fell silent at those words. Indeed, she had originally been a doctor, but she suffered from a terminal illness that medicine could not cure. Wanting to see her children grow up, she had searched desperately for a treatment. During that search, however, Muzan Kibutsuji had deceived her. After becoming a demon, she had lost control and killed her own husband and children. Under Muzan's control afterward, she had also eaten many humans. By all rights, someone who had committed such sins belonged in hell!

But before she went to hell, she still had something to do. She had to take revenge on Muzan! She had to eradicate that devil from this world!

Otherwise, even in death, she would never rest in peace!!

So Tamayo said, "I know I should fall into hell and suffer its torments, but I cannot accept leaving this world without destroying Muzan!"

Uzumaki Gamu replied, "Don't be nervous. Although I sense a kind of taint from you, Miss Tamayo, I can also feel your kindness. You should do the right thing, so I won't do anything to you either!"

"...Thank you very much!" Having met someone so understanding, Tamayo could only thank him for now!

"All right, enough of that... It's time I left!" His tea was finished, so it was time to go!

"Huh? You're leaving already?" Tanjiro asked in surprise. Hadn't they barely talked about anything yet?

Why was he leaving just like that?

"Time waits for no one. I'm off to kill demons!" After arriving in this world, he had also confirmed the point at which the mission began. There was basically nothing he needed to wait for. He just had to find Muzan and kill him!

Of course, to make sure he could actually finish off that coward, he needed to make some preparations first. Uzumaki Gamu intended to do that now!

Just then, Tamayo called out, "Wait! Since we're both targeting Muzan, then... why don't we work together? I have a plan..."

Uzumaki Gamu interrupted her. "Well... let's see how things go? But I don't think it'll be necessary. The moment I appeared here, Muzan Kibutsuji had only one possible ending... Muzan is dead! Not even Jesus can save him! I said it!!" After saying that, Ah Wei~~ no, Uzumaki Gamu left with the Body Flicker Technique!

Tamayo and Tanjiro were left staring at each other. What exactly had he come here for?

... Preparing ninja tools ...

After leaving Tamayo's home, Uzumaki Gamu began wandering around Tokyo late at night. Yes, Tamayo's home was in Tokyo's Asakusa district.

As he wandered aimlessly, Uzumaki Gamu thought, It should be around 1920 now... Well, Tokyo is already showing some signs of modernization! But at this hour, I suppose only the red-light district would still have people around? Uzumaki Gamu wasn't particularly interested in red-light districts, so there wasn't much left to explore.

Uzumaki Gamu simply found a spot to think through his next moves!

Uzumaki Gamu thought, First, the primary target of this mission is Muzan Kibutsuji. Killing him will end the mission and earn me the completion reward. However, the Dungeon System said killing demons increases the reward. But... once Muzan dies, all the demons descended from him will perish too... In other words, demons who die that way don't count toward my KPIs? Then, to maximize my profits, I should kill as many demons as possible before finishing Muzan off... In that case, there's no rush to kill him.

Uzumaki Gamu considered that approach for a moment. "I can't simply leave him until last, either. If that coward discovers all his subordinates are dead, who knows where he'll hide!"

Muzan Kibutsuji had absolutely none of the dignity of a powerful fighter.

The shadow of death had haunted Muzan before he was even born. His weakness had caused his heart to stop beating in his mother's womb, and he had even entered the world as a stillborn child. Although his obsession with living had driven him to claw his way back from death's door, his terminal illness still meant he was not expected to live past twenty. He spent his days bedridden. Those experiences had given him an abnormal fixation on life!

Even after becoming an ageless, immortal being who surpassed humans, he would immediately flee whenever he encountered a threat that might kill him. Centuries ago, when facing the strongest swordsman to wield a breathing technique-Yoriichi Tsugikuni-he had realized he was no match for him and split his body into over eighteen hundred fragments that scattered in every direction. He had then hidden away until Yoriichi Tsugikuni died of old age before emerging again. What a disgraceful creature!

Ugh... If I show too much strength, that guy will probably split into a bunch of pieces, bury himself somewhere, and hide like a turtle until I'm gone, then come out again, right? Apparently, he's even overcome decapitation and can regenerate from a single piece of flesh. Only sunlight can kill him... Being hard to kill is bad enough, but he's such a coward too... What a disgusting villain design~ Uzumaki Gamu couldn't help grumbling inwardly.

Even if Muzan really found somewhere to hide, it wasn't as though Uzumaki Gamu couldn't find him. He couldn't conceal himself from the Mind's Eye of the Kagura combined with Sage Mode. But... that would inevitably create unnecessary trouble.

Uzumaki Gamu didn't want to go digging holes everywhere looking for that man!

In short, to eliminate Muzan cleanly and directly, Uzumaki Gamu needed a method guaranteed to kill him!

"In theory, I just need to create sunlight!" Uzumaki Gamu said, clapping his hands. The Demon Slayer Corps clearly still lived in an older era and didn't understand much about science and technology!

Sunlight was ultimately just a kind of light. It wasn't impossible to produce. Uzumaki Gamu could head to Germany or America, the world's leaders in science and technology, find some scientists to develop a device that emitted sunlight, then use it to destroy Muzan!

At that thought, Uzumaki Gamu suddenly lowered his head dejectedly. "...It's a good idea, but... could they build a device like that in 1920?" Even Stroheim had only obtained ultraviolet lamps from German scientists to fight the Pillar Men around 1940. Where could Uzumaki Gamu find one twenty years earlier?

Besides, passenger planes couldn't handle extremely long-distance travel yet. To get from Japan to Germany or America, Uzumaki Gamu would have to take a ship... Didn't sea voyages take a month or so in this era?

Uzumaki Gamu couldn't help complaining, "That's just wasting my youth! At that rate, the Demon Slayer Corps will be finished!" In short, this method wasted too much time. Scrapped!

"Then the remaining option is... seal him with my sealing jutsu first? Then wait for dawn? That's just asking for more complications... Isn't there a more direct method?" As Uzumaki Gamu pondered this, he looked at his palm. "Wait. Whatever else I am, I'm a ninja... I have ninjutsu, which lets me take shortcuts. In that case... why don't I develop a ninjutsu that emits light similar to sunlight?"

Developing a ninjutsu seemed a little troublesome, but it was worth trying, so Uzumaki Gamu immediately put the idea into practice. After all, practice was the only true test of everything!

"First, ninjutsu that emit light are basically either Fire Release or Lightning Release, so I'll consider those as my foundations... Fire Release focuses more on heat and range. In terms of pure brightness, Lightning Release is stronger, and it comes in all kinds of colors. It can produce yellow light-Lightning Release: Lightning Ball-blue light-Chidori-purple light-Purple Electricity-and even black light-Lightning Release: Black Panther.

"In theory, it should be possible to produce light that counters demons... Maybe this could work?"

With that thought, lightning emerged from Uzumaki Gamu's palm. Looking at the blue lightning in his hand, he grumbled, "Changing its color feels difficult... I'll just have to keep experimenting!"

Just then, another thought struck Uzumaki Gamu. "Wait. Are demons afraid of sunlight itself, or ultraviolet rays? If it's ultraviolet rays, I wouldn't need to simulate sunlight. Wouldn't increasing the frequency of Lightning Release be enough?"

Ultraviolet rays were produced when an atom's outer electrons became excited. The main natural source of ultraviolet light was the sun, while artificial sources included electrical arcs in various gases, such as low-pressure and high-pressure mercury arcs. Compared with simulating sunlight, reproducing an arc like that seemed more feasible!

If he developed it, he would call it Lightning Release: Ultraviolet Technique... Aside from killing Muzan, it didn't seem to have much use. Maybe... if he visited the world of JoJo in the future, it could be especially effective against Dio?

If Uzumaki Gamu's theory was correct and Yama had arranged for him to kill people who refused to die, it might actually be useful later!

"Well... I'll work in that direction first. If it doesn't work, I'll use the mighty sealing method and let the sun destroy Muzan! But before that... time to start killing demons!!" To increase his reward, Uzumaki Gamu began hunting demons that very day!

Tremble, you damned monsters! It's time to descend into hell and face Yama's judgment!!

... Preparing ninja tools ...

After Uzumaki Gamu left, Tanjiro reached an agreement with Tamayo. He would help collect demon blood so she could research a way to turn demons back into humans.

Afterward, Tanjiro continued carrying out Demon Slayer Corps missions with his sister... Yet over the next few days, those missions didn't go very smoothly.

Every time he followed his instructions to the designated location, he found... no trace of the enemy!

Using his nose, Tanjiro could tell that the demons had already been killed. They left no traces only because demons turned to ash after death.

Had someone beaten him to it?

It must be Mr. Uzumaki Gamu, right? Tanjiro smelled the scent Uzumaki Gamu had left behind, so he credited everything to him. This also made Tanjiro marvel... Uzumaki Gamu really was strong! Killing demons so efficiently without leaving any traces clearly meant he had dispatched them outright!

Maybe... Uzumaki Gamu really could kill all the demons by himself? If so, does that mean I don't have to work hard anymore?

At that thought, Tanjiro hurriedly slapped his cheeks hard and rejected the idea. "I can't let myself get complacent like that! I can't leave something so dangerous entirely to others. Besides, I still have to save Nezuko! I need to work twice as hard!!" Just as Tanjiro was thinking this, a new mission arrived!

"South-southeast! South-southeast!!" The Kasugai Crow responsible for delivering the Demon Slayer Corps' orders flew to Tanjiro's side with new instructions. He was to head to a building the Corps called the Demon House and eliminate the demons there!

Tanjiro followed the instructions to his destination, then... saw the ruins of a house, some rescued civilians who were soaked to the skin, two unconscious Demon Slayer Corps swordsmen, and... Uzumaki Gamu!

"Huh? What's going on here?!!" Tanjiro ran over in a panic!

Hearing him, Uzumaki Gamu glanced in Tanjiro's direction and greeted him. "Oh, Tanjiro... Hey. It's been two days. You're looking pretty lively."

"Hello, Mr. Uzumaki Gamu... Um, what happened here?" Tanjiro asked, pointing at the people on the ground.

"Saved some people, killed some demons, got misunderstood, then knocked them out!" Uzumaki Gamu gave a brief explanation. Of course, Tanjiro couldn't understand an explanation that brief, so Uzumaki Gamu elaborated.

While hunting demons everywhere, Uzumaki Gamu had used his sensory abilities to reach this area, intending to kill the demon occupying the house.

It happened to be dawn at the time, so Uzumaki Gamu only needed to destroy the house to kill the demon. One Great Fireball would do the job! It would be effortless!

But things hadn't gone quite so smoothly. The demon occupying this house had captured a young man the previous night. The young man's younger brother and sister wanted to rescue him, so they had followed the trail of blood he'd left behind and were now stuck outside the house, unsure what to do~

Kindhearted as he was, Uzumaki Gamu naturally couldn't bear to see two children crying there, so he chose to send them to the afterlife to reunite with their brother... Just kidding. Uzumaki Gamu wasn't the Master of Logos. He wouldn't do something like that.

Back to the point: Uzumaki Gamu promised to rescue their brother, then entered the Demon House alone.

The demon occupying it was the former Lower Rank Six, Kyogai. The Lower Ranks were part of an organization Muzan had established to wipe out the Demon Slayer Corps! Its members answered directly to Muzan and were the twelve strongest demons. The Twelve Kizuki were divided into Upper Ranks and Lower Ranks, with the Upper Rank demons being the strongest among them.

Kyogai was an unlucky fellow who had been expelled from the Twelve Kizuki for being too weak! He was now occupying this house, hoping to increase his strength by eating humans, earn Muzan's approval, and return to the Twelve Kizuki.

His Blood Demon Art was Drumming. It could alter positions within the Demon House, and he could also rapidly strike all the drums on his body at once, making the house's rooms flip over continuously.

In short, it was... field magic!!

It barely qualifies as a spatial ability... Honestly, it's pretty useless~ Uzumaki Gamu grumbled inwardly. It only worked inside this house. If the house was destroyed, the Blood Demon Art would become completely useless.

Tanjiro and the others might find it difficult to handle. After all, they were merely swordsmen who cut people with blades and didn't possess that kind of overwhelming power. But for Uzumaki Gamu... it was far too easy!

After entering the house, Uzumaki Gamu used his sensory abilities to locate the captured older brother. Then, without even seeing Kyogai, he activated his ninjutsu...

Well, with someone nearby, burning down the house with Fire Release was clearly not an option. It would be rather awkward if he burned an innocent bystander to death!

At a time like this, he had to take the opposite approach. If fire wouldn't work, then he would use water!!

"Water Release: Great Waterfall Technique!!" This was an A-rank offensive Water Release ninjutsu. After gathering chakra in the throat, the user spat a massive ball of water forward to strike the enemy. Alternatively, existing flowing water could be gathered into a waterspout, then sweep over the enemy like a waterfall!

Although there was no water here, Uzumaki Gamu had so much chakra that he could turn Water Release into river release even in a waterless environment! His chakra still wasn't enough to make his Water Release resemble the adult Second Hokage's ocean release... For now, he was only at river-release level!

Still, river release wasn't to be underestimated!

For a little two-story house like this, a river's worth of water was terrifying!

And so, the house was torn to pieces by the torrent born inside it. Deprived of the house's shelter and exposed directly to sunlight, Kyogai died under the sun, bringing his wicked life to an end!

That was also why the three children were soaked to the skin.

After hearing the story, Tanjiro exclaimed, "Ninjutsu... can produce water directly too? That's amazing! But anyway... what happened to those two?" Tanjiro shifted his attention to his two fellow Demon Slayer Corps members!

Uzumaki Gamu answered, "They were outside when I destroyed the house. After seeing my Water Release, they thought I was using a Blood Demon Art and immediately treated me as an enemy. I'm not going to indulge anyone who draws a sword on me... One punch each, and they were out cold!"

Tanjiro broke into an embarrassed sweat. These two fellow Corps members he hadn't met before had been a little too reckless... In any case, he would apologize on their behalf first!

Tanjiro really was a good kid!