Starting from that day Kyoshi was being taught how to fight by Habuki. His suikendo was weird at first. It imitated the sense of water falling from a high place while the body was centered and the legs and feet practiced multiple striking and breaking moves.
Suikendo combined elements of combat, balance, and agility while also developing strength, flexibility and a "combat alert spirit". Kyoshi not only practiced these martial arts and worked out, but he was also trying to find out what his demon blood arts were.
Him and Keiko tried multiple things and testing, but he didn't seem to have one. Keiko's demon blood art was called "Vocal Maiden." Basically she had the ability to sing and people who heard it would go under three effects.
they would be under her control like goons.
They would have subjective thoughts that she could transfer into them.
Lastly, she would be able to completely break the mind of the person she's using it on.
When Kyoshi found this out he was completely enamored. A simple lyric from a song could get people killed or have somebody become her puppet. He was also bummed out because demon blood arts seem so cool and unique, but he didn't whine over it. After all he's still quite amazing or so Hanuki said.
His growth speed is spectacular. How fast he's able to grasp the concept of Suikendo was amazing. He was able to perform the moves and add his flesh manipulation into it as well to make it more deadly. Not to mention his strength, speed, and intuition.
When they're practicing he's like some totally different kid. Serious, determined, and almost like Muzan in personality. Kyoshi was able to find out what Hanuki's blood arts were when they were sparring and Habuki got cornered.
His blood art was called "Bunkai Teleport" It was a move that let his original body shatter into pixel-like pieces and re-emerge wherever he wanted. The move was instantaneous and freezed time in the real world, while he entered a pocket dimension.
A/N: Sorta like Janemba from DBZ.
After that day, Habuki promised that he wouldn't use it again since Kyoshi suddenly threw a temper tantrum complaining that he would've won if he didn't cheat. It's only been about 6 months since he came there and although he's learned a lot and was being treated well, he still wanted to meet Mizan.
They've only been staying in contact through animals that have been turned into demons, sending letters back and forth detailing Muzan about his progress while Muzan seemed to hold genuine interest in him.
Habuki and Keiko were confused at first. What made this boy so much more special than any other demon and why was Muzan so fascinated by him? They couldn't wrap their heads around it, but eventually they gave up on wondering about it and just decided to take care of him like they were told. It's not like they didn't like it though. At nighttime they would all go out and hunt in some villages that were a bit far away from the mountain so they wouldn't draw suspicion to themselves.
They also stole a lot of stuff like clothes, cameras, jewelry, etc. With the camera they took lots of pictures together and got stuff to decorate Kyoshi's room in their base. He got a proper bed even though they don't have to sleep, a desk, some shelves and his own journal.
So over the course of a year they grew closer and closer to each other. Muzan also took pleasure in seeing that Kyoshi was growing nicely and that he didn't seem to care about getting humans to kill for himself. They sent messages back and forth like Muzan was some inmate contacting his son.
He actually did something that shocked the soul out of Habuki and Keiko. He complimented them and gave them a bit more of his blood. He also made them the offer of joining the lower ranks of the Kizuki if they kept up the good work.
They were completely elated by this and promised him that they would see Kyoshi become the beat version of himself.
Something else piqued his interest as well and he chose to address it today.
…
"Muzan likes punctuality and professionalism, so make sure to act with respect." Keiko said as she combed out his hair. It grew to the point his bangs were past his chin and the back of his hair was put into a ponytail that stopped just below his shoulders.
Today Keiko and Habuki were sent a message from Muzan that he wished to see them and Kyoshi for a meeting he was having with the 12 Kizuki. So in a nervous rush, they started getting themselves ready.
They knew he probably wanted to see Kyoshi more-so than themselves and so they dressed him properly while they wore something they would usually wear. Habuki, wore some black gi pants, with no shirt or shoes and wore some bracelets that Keiko got him.
Keiko wore a long sleeved kimono that had a primary black color with flowers designed on it. She was "well endowed" so you could still see a bit of cleavage, but she was covered up for the most part and she left her hair as is other than combing it a bit.
Kyoshi wore a black kimono with white lining along with a haori of the same color. His bangs were braided and his hair was left in a ponytail. His style was simple, but professional. While he was trying to hide it, he was extremely excited.
He got to meet both Muzan and all the members of the 12 Kizuki! Habuki and Keiko told him they were the strongest demons in existence; how could his child-like heart not be excited?
"Alright this should be good." Keiko said as she stood up. Kyoshi got out of his seat and stretched before moving his ponytail behind his shoulder.
"Alright let's go." He said smiling as he left out the door. They met Habuki already in the room that they would be teleporting from and he seemed annoyed.
"It took you guys this long to do some hair?" He asked as he started drawing the symbol.
"We're meeting master Muzan so perfection is required." Keiko said, hunching her shoulders. Habuki sighed and completed the symbol. Just like the first time they were teleported here, the floor glowed a golden color and in the next moment they were on some brown platform inside what looked like a complex maze of infinite places and doors to go through.
This was called "The Infinite Castle.
…
Habuki and Keiko dropped to one knee and bowed their heads instantaneously. Standing next to them on a different platform were the 12 Kizuki and standing on a third platform in front of them was their master. Muzan Kibutsuji.
At their appearance, the 12 Kizuki looked at them from the side of their eyes while keeping their head down. All of them were confused as to why these three people were here and then they all went wide eyed at what happened next.
Kyoshi vanished from his spot and appeared again hugging Muzan like some kid that hasn't seen his father in years. The craziest part about it was that when Kyoshi stopped rather than killing him, Muzan smiled and rubbed his head.
'What the hell?' The 12 Kizuki thought simultaneously. Muzan glanced at them and opened his mouth to speak.
"Now that everyone is here, let's get down to business. Keiko and Habuki come forward." He ordered in a monotone voice.
They stood up and walked to the edge of the platform and stopped there. Muzan picked up two glasses that were next to his feet and put some of his blood in it. The Kizuki all were surprised when they smelled Muzan's blood, they knew what was going on the lowker moons were cursing themselves.
Keiko and Habuki started drinking the blood and once they were done, their body suddenly went stiff and veins started to bulge from their necks and forehead. They dropped to their knees choking with teary eyes and grit teeth.
"What's happening to them?!" Kyoshi asked in a concerned tone while pulling on Muzan's blazer.
"They're just getting stronger. If they can handle it that is. Everyone has a limit after all." He muttered.
"What'll happen if they can't?" He asked.
Muzan glanced at him before looking back at Habuki and Keiko.
"We'll just have to hope they can." He answered as he too was looking at them curiously. He wanted to know if they could do it. If they could get stronger and reach their full potential and hopefully break their curse of having to hide in the morning.
Even if they couldn't, he was fairly sure that Kyoshi would help solve his problem, but he needed more information. Information from when he was a human and not memories. He needed Kyoshi's original blood back from his human days.
However, that was impossible to get.
The blood from Kyoshi when he was a human was something that he was more interested in. He said he killed a demon before he turned into a demon himself, so he had to possess some type of power as a human, but now that his blood had been tainted he can't be sure.
His hypothesis though was that Kyoshi contained a large amount of RC cells, but they weren't active which was common amongst humans. What he was more interested in was the quantity of his RC cells and how his body was able to activate them.
RC cells are special cells in the body that don't particularly hold any use until they are activated. Some people are born with active RC cells and some people have RC cells that activate on their own.
Multiple era's ago there was a way for people to activate their RC cells which came in the form of breathing techniques and spiritually practices. Over time people stopped with these practices and breathing techniques were passed down from generation to generation, but there was a problem.
Demons.
The main reason people activated their RC cells and worked so hard was to fight and kill human eating demons. More and more demons started to be produced over the centuries while the number of people who fought them off dwindled.
People were scared and a lot didn't want to have direct confrontation with these scary monsters, but mainly it was the work. As technology started to become more and more advanced people became lazy.
They didn't want to be kept under such strict training nor be committed to something that would ultimately come with a lot of pain and most certainly death. So in the current time, people have almost completely forgotten about their RC cells.
All besides those of the Demon Slayer Corp, but I'll get to them later. When Muzan found Kyoshi, he was 10 years old. His body should in no way be capable of using his RC cells especially without proper training.
So he was confused and interested in the quality and quantity of his RC cells as a human, but now that his blood wasn't that of human blood and his RC cells have also most likely increased in quantity and changed in quality, he couldn't use them.
Or so he thought before.
Finally Habuki and Keiko got up while gasping for air and Kyoshi had a big smile on his face. They stood up straight and bowed their heads respectfully.
"Thank you Master Muzan for your gift. We'll be sure to serve with our utmost performance." Habuki said.
"Good, because I'll now be promoting you to a lower moon. Both of you." He replied with a slight grin.
The lower moons of the 12 Kizuki grit their teeth. They all knew damn well that Muzan would be getting rid of the two lower ranks to replace them with Habuki and Keiko.
Lower Moon Rank 6: Kamanue.
Lower Moon Rank 5: Rui
Everyone knew they were being replaced.
"Kamanue and Habuki. Rui and Keiko. You'll all be having a death match to see who stays and who goes." Muzan announced.
'Death match?! What kind of bullshit is that? Those guys are obviously-'
"You call my decision bullshit? Kamanue." Muzan said with a stern voice. His aura exploded and everyone in the room could feel it. Kamanue started having blood come from his eyes as he coughed blood.
"What about my decision is bullshit? Is there something on your mind?" He added.
"I-I would never have such a thought sir." He stuttered.
"So I'm lying?" Muzan asked.
"N-no sir."
"Pick one Kamanue. Is that not what you were thinking or was it? Make your choice."
"I-I-I thought about it! It's true!!" He yelled.
Muzan's aura went back to normal and Kamanue started gasping for air.
"So tell me. Was it bullshit?"
"No sir, but…"
"But?"
"But you've given them more of your blood. How can we compete with that? We can't just-…"
"Don't speak for me you coward." Rui said as he glared at Kamanue with his own aura increasing in intensity.
"I'll fight my battle and return to my family. This group will be all the more better without a weakling like yourself." He added.
"Tch, you haven't done a single thing since becoming a demon or a member of the 12 Kizuki! You stay on the mountain with your puppets and do nothing. YOU'RE USELESS TO THE GROUP!!" Kamasu yelled as he stood up and pointed at Rui.
Rui's eyes widened and in an instant he dashed towards Kamanue preparing to slash Kamanue's head clean off.
"STOP!!" Kyoshi yelled.
Everyone in the room turned their heads towards him.
"You can't kill him. How else will my uncle get into your group?" Kyoshi asked. Habuki chuckled dryly and scratched his head.
"The kid's right. How you lower moons behave in the presence of master Muzan is deplorable. Show some respect and close your mouths." Kokushibo, the Upper Moon Rank 1 demon.
"Yes, that's quite enough. The decision I've made is final. You'll have a week to do what you can to prepare." Muzan said.
"Yes sir." The four of them said in unison.
"All of the lower moons may now leave. Habuki and Keiko are dismissed as well." He said. Although they seemed hesitant they bowed their heads and left.
"How will I get home?" Kyoshi asked.
"I already have that figured out." Muzan answered. He looked towards the Upper Moons who were left in the castle and spoke.
"Raise your heads. This is Kyoshi, it'd do you well to become familiar with him."