Ryu was fighting a Demon not even trying hard as he parried the claws and punches.

Ryu: 'Killed 4 already, number 5 is gonna be my test dummy.'

He backflipped away before grabbing the giant sword.

Ryu: Magma Breathing, 2nd Form.

The blade glowed as Ryu readied himself to swing it forward.

Ryu: Searing Dance!

He spun around the Demons slicing all of it's limbs off while also slicing off it's head. He put the sword back on his back as it cooled off.

Ryu: Hm, I wonder what would happen to a Demon's regeneration if my sword is superheated and they don't die in one hit.

Once again he had heard cawing in the air looking to see it was his own crow.

Crow: Ryu Kaizen! You have been summoned to the Butterfly House by Lord Oyakata! Do not be late under any circumstances!

Ryu: Alright I hear yah.

He cracked his neck before stretching.

Ryu: How far is it from here?

Crow: It would be a trip that last a 5 hour run.

Ryu's eyes flashed before he began running and blinding speeds.

Ryu: Should be there in a minute or two if I keep this speed up.

TIME SKIP!!

BUTTERFLY MANSION

Rengoku: Believe me when I tell you Master, that man is something special. He along with the woman he's traveled with.

Rengoku was bowing in front of a man with his head and hand on the ground.

KAGAYA UBUYASHIKI!!

Behind Rengoku were 8 other Demon Slayers who were simply just kneeling watching Rengoku bow.

THE HASHIRA!!

Fang: If you thought I was gonna individually name 8 people at once you're insane.

Kagaya: Rengoku, you are an honest man, but it is still hard for me to believe what you are saying.

Sanemi: A man who can defeat a Demon with his bare hands is impossible with the exception with Gyomei!! Do you really expect anyone here to believe that he defeated one of the 12 Kizuki doing so?!!!

Shinobu: It is hard to believe.

Rengoku: It may have been the lowest of them, but it's still one of them. I've even seen his strength with my own eyes.

Mitsuri: 'For Rengoku to bow and speak this highly of someone, he must be powerful and dear to him.'

Muichiro: ...

Kagaya: Well, when he arrives we will have to see.

Right then they had heard a sonic boom in the distance.

Obanai: What in the world could that have been?

Rengoku looked back knowing exactly who this was coming from.

Rengoku: If I were a betting man...

There was a sudden gust of wind making everyone close their eyes. When it stopped it was revealed that no one was there.

Shinobu: Well that was a little... Anti Cli-

Ryu: Look up.

They all followed the sound of the voice and saw Ryu with an apple sitting on the roof of the mansion. He bit into it pleasantly surprised.

Ryu: Hm, sweet apple.

Rengoku: And that, is my student.

Gyomei: Incredible. If he didn't say anything I'm not sure if I would've felt his presence.

Ryu dropped onto the ground with the eyes of the Hashira still on him.

Ryu: What? It's not like I'm gonna vanish out of sight right when I just got here.

Rengoku pointed to behind Ryu as he turned and saw a smiling Kagaya. Putting two and two together seeing that not one Hashira was standing on two feet knelt himself.

Ryu: It's an honor to finally meet you.

Shojo: Fun fact readers, Ryu can be respectful when he's in a good mood.

Kagaya: So you are the one who Rengoku had trained for only 2 months but already has such respect for?

Ryu: Yes. My name is Ryu Kaizen.

Kagaya: I understand. Is it true you've defeated one of the 12 Kizuki alone? And truly in one strike.

Ryu: Yes. Even though it seemed pretty arrogant, I still know I would've defeated it without any trouble.

Tengen: 'Hm. Confidence with a good bit of style. I like him.'

Kagaya: And is it true that Rengoku has yet to hit you when you both have sparred on numerous occasions?

Ryu: Yeah, that's right.

Kagaya: I understand. There was no waver in the voices of yours or Rengoku. Tell me, what breathing style do you use?

Ryu: Well, I have the Flame Breathing that's been taught to me by Rengoku, and I created my own Breathing derived from it called Magma Breathing.

They all heard a slam on the ground as it was revealed to be the fist of Sanemi.

Sanemi: Forgive me for speaking out of term Master, but it's impossible for someone like this to have already created his own Breathing Style in the span of what they claim to be only 2 months!!

Ryu looked back at Sanemi with a confused expression.

Ryu: Well once I see an example of something it's not exactly difficult to replicate the movements. Creating it took more time but nothing really to-

Sanemi: Replicating someone's exact movements are easier said than done!!

Ryu: *Sigh* Well I can't exactly prove it to you with just my words alone can I?

Ryu turned back to Kagaya looking down.

Ryu: Lord Oyakata, would you allow me to spar the Wind Pillar if only to show him that neither I or Rengoku are are giving false information.

Kagaya seemed to ponder this thought before nodding.

Kagaya: Well I suppose it wouldn't be a problem so long as the two of you only use the forms and not apply your elemental effects. There are two wooden swords in the back.

Fang: Just me again, the effects are real for fun damnit.

Sanemi was the first to get up and rush to get two wooden swords.

Sanemi: I admit you might have speed but it takes more than physical power to create a breathing style! I will see for myself if you truly are as talented as Rengoku claims!!

Ryu cracked his neck getting into a stance saying nothing.

Sanemi: 'Wind Breathing: 1st Form!!'

He launched at Ryu with incredible speed spinning.

Sanemi: 'DUST WHIRLWIND CUTTER!!!'

Right before he could get hit Ryu seemed to have vanished out of thin air. Sanemi stopped shocked and confused.

Sanemi: Where is he?!

Ryu appeared a few yards away from Sanemi preparing his own attack.

Ryu: Magma Breathing: 4th Form.

Ryu gripped his blade before swinging it forward causing a blast of wind to hit Sanemi.

Ryu: Scorching Slash.

Sanemi was knocked into a wall with Ryu slightly shocked.

Ryu: ... So are we going by the rule of the first to get hit or the one to be knocked out? Cause I~ might've done both.

Sanemi got up slowly looking at Ryu.

Sanemi: What in the world was that?! It looked like an ordinary slash!

Ryu: Keyword is looked. That swing had force enough to break a boulder.

Sanemi couldn't keep standing as he fell flat on his back.

Sanemi: 'Damnit he's right! That attack knocked the wind out of me!!'

Sanemi looked at the sword he tried to block with seeing it got snapped in two. Each of the other Hashira couldn't even fathom how he had beaten him so quickly as Rengoku watched with a smile. Ryu walked over holding a hand out.

Sanemi: Are you looking down on me?!

Ryu: Only the weak do that.

Sanemi looked at his hand before scoffing and slowly picking himself back up.

Shinobu: 'So Rengoku wasn't exaggerating his strength. Not one bit.'

Giyu: 'This guy...'

Ryu knelt back down sticking the wooden sword into the ground.

Ryu: Thank you.

Kagaya: No Ryu, thank you. It's been generations since a Demon Slayer of your a caliber has arrived. Although it wouldn't exactly be right for you to become a pillar right away, I don't think it's far fetched to let you become a Kinoe.

Ryu: If you think that's the right choice. Another 50 Demons or 12 Kizuki Demons is a small number when you think about how powerful a Hashira really is.

Kagaya: With that logic it would. Also, I'm keeping an eye on the Ruby Rose girl as well. She is powerful as well correct?

Rengoku: Yes, although she is not nearly as powerful as Ryu is, she has still proved to be in a league above my own.

Kagaya: Very well. Oh, and check your ranking with your pass code.

Ryu: Remnant.

Ryu clenched his right fist seeing the marking had changed to Kinoe.

Ryu: I'm humbled. Before I go, may I ask about that... I want to say sickness but it honestly look like a disease I've seen were I come from.

Everyone hearing this was shocked beyond belief.

Muichiro: Did you just say you've seen that curse?

Ryu: Like I just said, more like a disease, but yeah. It's kinda rare, but the side affects include death before or in 30's, frailness of the body, and sight is destroyed after so long.

Kagaya: I see. Might I ask how many survivors you've heard of?

Ryu: Hmm, about 20 before it stopped... I memorized the components of a cure so it should actually be pretty simple to help you out.

There was an unwavering silence when those words escaped Ryu's mouth. When he realized that he said that himself he internally facepalmed.

Ryu: ...

All: ...

Shojo: You dug your own grave on that one buddy.

Everyone's eyes were on Ryu as he sweat dropped.

Ryu: If I get to work on it now then it'd be done in a day-

All: EHHHHH?!!!!

TIME SKIP!!

Ryu was repeatedly hitting his head on a desk as he seemed to be at work grinding herbs in a bowl constantly having to stop and pull things out of thin air.

Ryu: -_- Why does the kind part of me always come out of nowhere when it see's a sickly person?

Ruby and Rengoku were watching him as Ruby seemed slightly confused.

Ruby: So Lord Oyakata's sickness is just a bad case of Herophytus Ryu?

Ryu: -_- Yeah pretty much.

Rengoku: Ryu, what you're doing is an amazing thing! If you are successful in finishing that cure then the master will be able to help us even more with his foresight in the long run!!

Ryu: Yeah I guess.

Ruby: Also I'm gonna address the obvious question- How do you know how to do this?!!!

Ryu: If I've seen it done once I can do it Ruby. You know that.

Ryu seemed to turn off his own aura and bit on his thumb.

Rengoku: Why would you need your own blood?

Ryu: Because it requires the blood of someone with a healthy body and an AB- blood type.

Ryu wrote down some notes before adding just a drop of blood into the liquid he had concocted as it seemed to turn a dark shade of blue.

Ryu: I did warn you though that there is a 40% chance this doesn't work.

He brought out a syringe needle sucking the injection for flicking the glass to make sure it was even.

Rengoku: If nothing bad happens then we are all willing to take that chance!

Ryu: -_- For someone else.

Rengoku had noticed something looking at Ryu.

Rengoku: Where did the cut on your finger go?

Ryu: Healed.

Rengoku: So quickly?!

Ryu: Yeah a lot of shit has happened to me so I can basically heal minor wounds like this pretty fast. Kinda like a Demon.

Rengoku: Fascinating. Is that also the reason for your incredible strength?

Ryu: No that was just a result of 24/7 training for years and years. Anyway this is it.

He handed the injection to Rengoku.

Rengoku: Why are you giving it to me?

Ryu: Give it a sec.

Crow: CAW!! RYU, RUBY!! YOU HAVE A MISSION!!

Crow: YOU AS WELL RUBY ROSE!!

Ruby: How did you even-

Ryu: Instinct. Let's go Rubes. I'm trusting you Rengoku.

Rengoku: Leave it to me!! Now go!

CHAPTER END!!