All of the Hashira aside from Tengen who had retired where in a meeting room with Ryu as nonchalant as ever.

Sanemi: Ugh, I envy you guys. Why can't I bump into Upper Moons?

Ryu: Trust me, it gets annoying after too long.

Iguro: It's not like people bump into the all the time. But how are you two doing, Kanroji, Tokito?

Mitsuri: Oh, I'm feeling a lot better!!

Tokito: I... I'm not at full power yet, but I'm better off than I would've been if Ruby didn't show up when she did.

Ruby: You're welcome.

Gyomei: If we lose any other Hashira with the alarming growth of the Demons, the Demon Slayers will be in trouble, but defeating another 2 Upper Moons without a casualty is very noble indeed.

Shinobu: You two recovered surprisingly quickly from this.

Ryu: Not only that, it looks like you both have what we're here to talk about.

Giyu: I don't think that's all Master Oyakata wanted us to talk about.

???: That's right.

They all looked to see Kagaya but he was different. He no longer had the rash over his face and in fact it was clear and his eyes were a pale blue. Ryu seemed to sigh in relief.

Ryu: It's done. That antidote was fully worked through you master.

Kagaya: I am eternally grateful to you, Ryu Kaizen.

Ryu: Your gratitude is all I need.

Kagaya: As you all know, there is only one Upper Moon left in the world. Sadly, that is the most powerful one there is. Upper Moon One. Though he may be powerful, I do believe that he isn't an insurmountable object. And Nezuko Kamado has recently conquered the Sun, so Kibutsuji will be after her now. Ryu, Muichiro, Kanroji, you all have had marks appear on you correct?

Ryu pulled his collar down revealing three dots on the right side of his neck.

Shojo: 'Oh that is just too perfect. Naruto fans, you should know this.'

Ryu: But the fact is the none of us here unlocked the "Demon Slayer Mark" first. It was Tanjiro Kamado.

Ruby: I think I first noticed it when he battled one half of Upper Moon 6 with me. He used the Breath of the Sun during that fight. I tried asking how he got it at first but as it turns out-

Rengoku: His explanations were... Less than helpful.

Ryu: Before we continue this further, Master, you must know something more about this mark correct?

Kagaya: Yes. In the Sengoku Era, there were warriors of the first breath that had these marks and were close to defeating Kibutsuji. It was hidden since some became envious that the marks hadn't appeared. The most important detail is that once one has this mark, it begins spreading to others as if they're resonating.

Ryu: *Sigh* That might be bad.

Shinobu: Why would that be?

Ryu: Well, through my own experience I found out how to forcibly unlock the mark.

Sanemi: Then don't hold out! How can it be unlocked?!

Ryu: There are two conditions that are deadly for most. Me having been close to those points multiple times it doesn't effect me greatly but in order to unlock the Demon Slayer Mark, your heart rate has to be over 200 and your temperature has to reach past 39 degrees celsius.

Iguro: Is this a joke?

Shinobu: Those conditions are madness for human beings.

Rengoku: He speaks the truth. I've seen the training Ryu has done and he unintentionally unlocked the mark through it.

Sanemi: Tch. So it's that simple?

Giyu: I envy those who can say this is simple.

Sanemi: What?

Giyu: Nothing-

Ryu: You're dumbass has ears. Now why it could be bad news. The Mark also tries to eat away at someone's life force.

Everyone's eyes minus Kagaya's and Ryu's widened.

Ryu: For anyone who's got a normal life force, it's possible their lives will be cut short at 25.

Ruby: That's definitely bad news.

Ryu: Unless they're born with it, most likely like Tanjiro, there's no exception. Not unless your willpower is stronger than your life force.

Kagaya: I see.

Ryu: BUT it's not impossible to live through. I say there's about a 30 percent chance you can live through it.

Ruby: -_- Great, you gave us the odds.

Kagaya: Well, that is all. I must be going now.

Soon the man had gone as only the Hashira were left in the room.

Giyu: I'll be taking my leave now.

Sanemi: Whoa, hold it. Don't leave just yet man. We oughta make our future plans now, am I right?

Ryu: -_- What have introverts ever done to you?

Giyu: Then you nine can talk about it. It's got nothing to do with me.

Iguro: What do you mean nothing to do with you. Or what? You planning to get a head start on training without us? Don't say such a thing during the meeting.

Ruby: Iguro, lay off.

Giyu had gotten up beginning to walk away.

Sanemi: Hold it damnit!!

Shinobu: Tomioka, please, just tell us why. You're leaving out a lot of details.

Giyu stayed silent for a few moments.

Giyu: ..... I'm not like you guys.

Sanemi had taken offense to that comment.

Sanemi: Wow, you're pissing me off. You said the same thing before Tomioka. Are you making fun of all us?!

Mitsuri: N-No fighting you guys!! Let's be-

Sanemi: HOLD IT FUCKWAD!!!

Ryu snapped his fingers causing a shock to go through the room diverting everyone's attention to him.

Ryu: Giyu, I know what you meant to say, but wording is pretty important. Also, calm the fuck down before I make you hot head.

Gyomei: May I make-

Ryu: No.

Gyomei: ... You didn't even let me finish my sentence.

Ryu: And that saved a lot of time.

Ryu looked towards Giyu.

Ryu: Dude, I know depression when I see it, trust me.

He got up putting a hand on the Water Hashira's shoulder.

Ryu: But, are you really going to let everyone up until now down because of it?

These words seemed to hit Giyu harder than anyone was prepared for. Right as he was about to say something something in the back of Ryu's mind surfaced.

Ryu: AH SHIT WE NEVER GOT TO GET SYAKE DAIKON LIKE WE PLANNED IN THAT FOREST!!!

Giyu: ... You remembered that?

ONE HOUR LATER!!

Ryu and Giyu were sitting down enjoying salmon braised in red whine with daikon radish.

Ryu: Hm, you know, this isn't the first time I've tried this, and it definitely won't be the last.

Giyu only nodded in agreement in the middle of biting down a radish.

TIME SKIP!!

Ryu: COME ON, STOP SLACKING!!!

Ryu was currently going against multiple Demon Slayers that were armed with their actual Nichirin Katana's while he was only armed with a single wooden sword.

Not enough of handicap for the rest honestly.

This was apart of the Hashira Training for the finale fight against Muzan. The first thing to do would be to pass the stamina training under Tengen, the next would be combat speed with Muichiro, then after that Mitsuri would focus on flexibility -GO TO CHURCH- and next Iguro would focus on strictly swordplay, while Sanemi would handle endurance by beating the everliving daylights out of whoever came until he saw fit. After that was done, they'd be with Gyomei focusing on muscle reinforcement to allow them to use all of their strength, and after they moved on from that they would train with Rengoku to enhance the power of their Breath Techniques. Second to last was Ruby who taught them to use their speed to its fullest extent without getting tired after a single burst. And then there was Ryu. His training made each of them use everything they learned in battle against him.

Needless to say anyone who had made it to that point felt like they'd rather deal with Muzan himself.

Ryu: 'I'm honestly considering hunting him down myself at this point.'

Shojo: Patience is a virtue Ryu.

Ryu: Alright people, take a break, I'm gonna check how the other Hashira -Just Sanemi's- Training is progressing.

Ryu vanished before going to the Wind Turf.

Ryu: That dumbass better not fuck anything up more than he has to.

He entered the training area seeing multiple people on the ground, one of them being Zenitsu.

Ryu: JESUS FUCKING CHRIST!!!

Zenitsu: RYU, HELP ME!!! I CAN'T GO ON WITH THIS ANYMORE!!!! HELP!!!!!

Zenitsu clung to the leg of his pants before being soundly slapped.

Ryu: GET A HOLD OF YOURSELF BOY!!!

Zenitsu: Q_Q I think I needed that.

Ryu: -_- He really fucked them all up that bad.

That's when they heard a crash as through the doors came Tanjiro and Genya tumbling out. A furious Sanemi walked out.

Zenitsu: HE'S BACK!!! HE'S BACK!!! THE HEARTLESS EVIL MAN!!! HIDE!!!! PRETEND TO BE DEAD!!!!

Tanjiro: What are you doing?!! Are you trying to kill Genya?!!!

This comment didn't go unnoticed by Ryu.

Sanemi: I'm not killing him. That would be easy, but against the code of conduct. I'll just leave him incapable of regenerating! When he does, he can quit the Demon Slayers and I'll forgive him.

He felt a hand grab his head before sweating profusely.

Ryu: -_- Don't even try and get a word out, you knew the fucking deal.

Tanjiro: What deal?

Ryu: Take shit too far and he gets leaned.

Tanjiro: ... Leaned?

Ryu: Observe.

Ryu did the according.

Pulled back his fist.

Turned Sanemi around.

And hit him with the MEANEST right hook any of them had ever seen.

Tanjiro: OH GOD!!!

Ryu: And THAT Tanjiro, is how you properly lean a mother fucker.

He blew the smoke off of his fist seeing Genya with his mouth open in horror.

Ryu: Kid calm your shit I only knocked him out.

He looked at Sanemi before checking his pulse sighing in relief.

Ryu: Yeah he's just out cold.

Tanjiro: ... Does this mean this part of our training is-

Ryu: Over? Yes. Yes it is. Hell I might just up and ask the master to remove this part entirely. Good luck with the next two before me.

Zenitsu: WE HAVE TO TRAIN UNDER YOU?!!!

Thunder struck down as Ryu looked back with a smirk that widened to ridiculous proportions.

Ryu: Bye~!!

TIME SKIP!!

Many weeks had passed as Ryu seemed to be waiting patiently on the top of a cliff. The only ones that actually came Ryu had passed out of pity. He soon realized that they were the only one's to come in the entire time for the months they had trained.

Ryu: Tanjiro, Inosuke, Zenitsu, please get here soon. Hell I expected Kanao to get here before anyone else.

???: THE WAIT IS OVER!!!

He turned around seeing everyone he had just mentioned.

Ryu: Speak of the Devil and he shall appear huh? Or they specifically.

He jumped down in front of them as only then each of them realized his immense presence.

Tanjiro: 'Th-This is what it's like to have to battle someone like Ryu?'

Inosuke: 'He's definitely in his own league...! Tanjiro said he even admits that he's not some regular human!'

Kanao: 'This must be how normal slayers feel when the encounter an Upper Moon...'

Zenitsu: '... We have to do this.'

Ryu: Everything up until now has been leading up to my training. Draw your blades.

Tanjiro: But isn't that dangerous?!!

Ryu: Haha! Don't worry, I'm only gonna be using this.

He showed the wooden practice sword surprising the others.

Kanao: Do you really plan on doing that?

Inosuke: ARE YOU MAKING FUN OF US?!!!

Ryu: Kids, do you really wanna deal with me using an actual sword against you?

Each of them had thought back to literally every time they had seen Ryu using his actual sword. For Tanjiro it was obvious as the first time he had seen the hero's swordplay was against Kyogai easily cutting off his head faster than he could perceive. For Inosuke he had the same experience in the forest with Rui's father. Zenitsu's very first experience he remembered was against Ryu beating both Akaza and Doma. For Kanao however, her only real demonstration for Ryu was how he cut through 5 boulders at once.

Yes you read that right.

They all shook their heads before drawing their swords.

Ryu: That's what I thought.

Ryu looked and saw Tanjiro had a new sword. The shade of black was deeper and the edge seemed to have flames while the hilt resembled the one Rengoku used. The thing that stood out the most was how there was the kanji for "Destroy".

Ryu: Come at me like your life depends on it.

He walked forward dragging his blade on the ground. He vanished from their sights as Tanjiro tensed up. They all sensed a heavy presence behind them knowing Ryu was about to attack.

Tanjiro: 'DAMNIT!! NOT AGAIN!! MOVE!!!'

Surprisingly Zenitsu while awake had pushed Tanjiro out of the way as a burst of wind came from Ryu's downwards swing blowing each of them back.

Ryu: Huh, who knew the coward could actually fight awake? Someone's got their confidence.

Both Kanao and Inosuke flanked him trying to catch him in a pincer attack.

Inosuke: YOU'RE DONE!!!

They both swung but found that they had clashed blades with each other.

Inosuke: THE HELL?!!

They looked up seeing Ryu falling before he paused in the air split kicking the two away.

Ryu: Come on, at least make me using a breathing art.

He sensed an attack coming before stepping to the side avoiding a speeding Tanjiro.

Tanjiro: 'Flash Dance!!'

Ryu: 'Sun Breathing.'

He hit Tanjiro on the back with the sword making him fall down.

Ryu: That's a bad habit Tanjiro! If you go in for a charging attack like that then don't give the enemy the time or room to land a counter if they dodge!!

Inosuke: 'Beast Breathing, Second Fang: SLICE!!!'

Inosuke slashed at Ryu's back with both blades but saw that they only sparked off him.

Inosuke: What the hell just happened?!!

Ryu: Blades will need to be sharper than that to scratch my skin.

He swung his blade not hitting Inosuke but sending him flying from the air pressure. Kanao ran in trying to attack almost seeing an opening.

Keyword: Almost.

Ryu caught the blade with his bare hands with Kanao questioning everything she had ever known up until that moment.

Ryu: Don't take the obvious bait Kanao.

He raised her blade throwing it back and her along with it. Zenitsu had come in attacking as Ryu dodged each one kicking him over to a tree. The blonde corrected himself landing on his feat readying himself for an attack.

Zenitsu: Thunder Breathing, First Form: Thunderclap and Flash, Eightfold!

He dashed as fast as lightning towards Ryu only for his attack to be dodged. He landed on another three bounding back making Ryu block that time. This pattern continued impressing Ryu.

Ryu: 'I didn't think the kid could get his confidence. Not bad at all Zenitsu.'

For the eighth and final attack Ryu had gripped his blade.

Ryu: Magma Breathing, First Form: Eruption Blade!

Their blades clashed as to no one's surprise Zenitsu had been sent flying back. They all gathered around Ryu readying to actually formulate a plan Ryu rose his hand.

Ryu: Take five you lot.

Tanjiro: Huh? Already?

Ryu: Yeah, you kids earned it. You managed to do this after all.

He held up the sword revealing that it broke in half.

Ryu: Your goal was never to beat me. It was just to break the weapon for now.

Inosuke: HOW THE HELL WERE YOU ABLE TO DO THAT?!!!

Ryu: Do what?

Kanao: He's right. You caught my blade with your bare hands and his swords did nothing to you.

Ryu: Oh right. Well kids I have this little thing called aura. It basically provides a forcefield around me at all times. Mine is kinda special though. It's mutated to be harder than steal.

Inosuke: Lutabed?

Zenitsu: NOT EVEN CLOSE DUMBASS!!!

Tanjiro: To be fair I didn't know about that word until recently either.

Kanao: It means something's genetic makeup changing.

Ryu: There's a lot more to it but that's way over your heads. Next round I'll actually try a little.

Tanjiro: ... Y-You mean you weren't even trying before?

Zenitsu: Th-This is gonna be t-tougher than I thought...

Zenitsu resisted the urge to scream as Kanao shook along with Inosuke.

Ryu: This is why my training was last. There others were all fun and games compared to me.

They all looked at him determined.

Shojo: Looks like you lit a fire in those kids.

Ryu smirked.

Ryu: 'I think they'd be fine without me.'

CHAPTER END!!