Muzan, who sensed Giyu coming up from behind him a while ago, smirked:
"Hello there, Hashira."
Swiping at the neck of Kie, who was petrified in place with confusion, Muzan mockingly glanced at Giyu.
Perhaps it was due to Muzan turning his head to look at Giyu, Muzan's hand didn't rip off the neck of Kie, but instead, it somehow hit Kie's head.
Frowning, Giyu launched another fierce attack:
"Breath of Water: Fourth Form - Striking Tide."
Evading the blow of Giyu, Muzan brandished his claws as he prepared to use the trees behind him as a springboard to pounce onto Giyu.
Sensing something wrong, Giyu immediately changed from an offensive posture to a defensive posture.
"Breath of Water: Eleventh Form - Dead Calm."
Just as Giyu got into his eleventh form, Muzan sent out numerous bone spikes and jumped from the tree's trunk.
*BOOM*
The tree got annihilated by the force input by Muzan, sending tree fragments everywhere as he propelled forwards.
Giyu, still standing in the same spot, calmly deflected all of the bone spikes and prepared for the incoming impact of Muzan.
As Giyu and Muzan continued to fight, with Giyu mostly defending, Kiyomi got closer and closer to getting rid of her paralysis.
Nezuko, beside her, wouldn't be waking up until half an hour after the sun had completely risen, and luckily, the dark clouds covering the sunlight would be able to protect her from disintegrating.
Standing up with slight difficulty, Kiyomi's body trembled as she struggled to walk:
'I can't reveal my hybrid form to Giyu, or else he'll most likely get rid of me first! Good thing I created that earing that can hide my demon aura from Humans. But how should I help him?'
Kiyomi first coped with the numbing paralysis as she walked around the battle area of Muzan and Giyu, deciding to leave behind Nezuko, who would definitely be fine for the time being, and walked into the house from the back.
As soon as she walked in the door, a group of children-Hanako, Shigeru, Takeo, and Rokuta-ran to Kiyomi and huddled around her.
"Nee-san!"
Hanako and the others, scared, could only rely on Kiyomi to give them a sense of comfort.
Their second eldest sister had disappeared, their mother in now unconscious, their father had died a few years ago, and Tanjiro, who they treat as their fatherly figure, was not there at the moment.
Comforting the scared children, Kiyomi hugged everyone:
"It's okay... we'll be fine. Let me sing you guys a song and everything will be alright.."
Kiyomi's soothing voice brought the panicked children a little calmer, and Kiyomi, who was singing lightly, kept some of her attention on the battle outside.
After finishing her song, Kiyomi put the children back to bed and told them to never come out of the house, no matter what they hear.
Opening the door and hugging her mother and taking her inside the house, Kiyomi assessed the overall situation of Giyu's battle with Muzan.
'Overall, Muzan is still definitely holding back a little, and Giyu can only mostly defend as his eleventh form gives him many chances to counter-attack, but his speed is too slow compared with Muzan.'
Grabbing the woodcutting axe, Kiyomi walked to the front door and was just about to go and help Giyu before hearing her siblings' anxiety and worry for her:
"Nee-san, be careful..."
"Be safe, nee-san, I'm still waiting for you and Tanjiro to chop wood with me together!"
Opening the door, Kiyomi stepped out of the house and took one last glance at her siblings, and smiled brightly:
"I'll be fine. You guys just stay inside."
Seeing the slowly closing the door, the children saw the scene of destruction behind Kiyomi.
Takeo: "...I knew nee-san was amazing..."
Hanako: "Stop... We are all thinking what you're thinking."
If Kiyomi were to hear Hanako's words, she would definitely laugh and say:
"When did you little girl learn to talk like me??"
Out on the battlefield...
Giyu: "..."
Muzan: "..."
Giyu was bleeding slightly, his originally clean haori has somewhat ripped and stained by soil.
Muzan on the other hand was still smiling mockingly at the water pillar, taunting:
"Is this what the slayer corps call a Hashira? You're pathetically weak."
Kiyomi, hiding behind a tree, slowed her breathing and lowered her presence as much as possible before inching towards Muzan's back.
During the nine years of peace, she has developed another breathing technique that she uses to offset the pressure brought by the continuous use of Moon breathing.
She couldn't think of a name for this technique, but its uses as the first-ever auxiliary breathing are absolutely amazing.
The main benefit is that it offsets pressure after each technique used so that the user would be able to continue attacking with no pressure build-up on the lungs and heart.
Taking inspiration from the rule of the Transparent World and the Kagura Dance, this new auxiliary breathing technique combines the continuity of the Kagura Dance and the ability to see your internal organs.
This new ability by combining the two is the ability to control your own body to relieve the pressure on your lungs and heart, and other uses include the user's own comprehension and creativity.
Technically, the pressure relief effect is just a way of advanced control over your body, so other uses include presence diminishing by controlling the lungs and controlling different parts of your internal organs to achieve different effects.
Of course, if this technique is to be perfected, it wouldn't be impossible for one to live forever, to achieve the automatic training of the muscles, and renewing all the dead cells manually, destroying bacteria, and creating antibodies.
All of these that your body knows at birth, and all of these that would eventually all cease to automatically work, would be able to be manually controlled.
It would be like oiling the rusted parts of a huge contraption and thus prolonging the shelf life of that gear many times over.
In simple terms, if you can control your body down to every single cell, you can biologically become immortal.
Kiyomi, who had developed this ability, didn't think so far yet, and only has discovered two of the abilities of the technique she created.
But what would happen, when an already immortal demon hybrid, achieves perfection in this ability?
Creeping up behind Muzan without him noticing, Kiyomi cut down on Muzan with one decisive and silent strike.
*Ding~sch*
The iron of the axe definitely was stronger than the wooden sword of Kiyomi, but even so, it only drew a single drop of blood from Muzan.
Kiyomi eyes lit up seeing this drop of blood, and immediately used her demon blood art.
The blood that was stuck on Muzan's hair went up from the axe and was absorbed by Kiyomi the moment it touched the skin.
Muzan, who finally noticed Kiyomi, stopped talking with Giyu:
"Kiyomi, oh Kiyomi... You should've gone for the head."