3rd POV. Infinity Castle.

After the battle with Upper Three concluded.......

Sora took his time to rest.....while watching over Tanjiro, Giyuu, and Kyojuro.

Sora: We can't waste any time now.

Sora: But I can't leave the three of them behind.

As he is in the middle of his thoughts, Giyuu was the first to wake up......

Giyuu: Sora, why are you-

Sora: I have to watch over you three. You guys really took a hard beating.

Giyuu: Don't worry. You got to go to where Muzan is.

Sora: Right.

Giyuu: I'll watch over Rengoku and Tanjiro.

Sora: Thanks.

Sora slowly stands up and began to navigate throughout the castle. Behind his resolve to kill Muzan, he is worried about Kanae and Shinobu facing Doma.

However, on their side.........

A lot just happened while Sora was battling Akaza.

Doma, revealed the backstory of Inosuke's mother, along with his origins.

Doma said that he wasn't planning on killing Kotoha and even wanted to stay because he liked her singing.

However, when Kotoha discovered Doma's nature as a demon, she ran away with the infant Inosuke on her arms.

She had no choice. She can't stay at the roadside, she can't return to her abusive husband.

So Hashibira Kotoha made the ultimate sacrifice. By letting the infant Inosuke fall into the river......while Doma consumed her.

Now knowing of Inosuke's origins, the boar head became even more motivated to defeat Doma, in order to avenge his mother.

With Kanae, Sora, and Kanao, who were also fueled with hatred by listening to the tragedy of Inosuke's mother.

They are currently in a deadlock because they can't catch up with Doma's speed, except for Shinobu but her poison isn't working, or so she thought.

Kanao whose eyesight is sharp, she noticed that the poison is slowly taking effect. With Shinobu even injecting more doses.

With this in mind, they began to plan on how will they take Doma down.

The plan is, Kanae and Kanao will deflect Doma's attacks.

While Shinobu will continue to inject poison on Doma to wear him down, while Inosuke is the one who'll deal with the heavy damage.

But they also agreed that if they found an opening, they'll go for it.

Kanae: Sora, along with Tomioka-san, Rengoku-san, and Tanjiro already defeated Upper Three.

Kanae: We must also do our best!

------------

Flashback. During the Hashira Training.

The dojo of the Butterfly Estate is currently being used by two people who are sparring with wooden swords.

Kanae and Sora.

Sora: I see......

Sora: Imitating the movements of the flowers and fruits, huh.

Kanae: Hm?

Sora: So it was based from the Water Breathing's flowing movements.

Kanae: Yeah.

Sora: Hmmmm.......

Sora: Alright........

Sora: The Flower Breathing after observing it while sparring with you......

Sora: It has to be coordinated with your eyesight and body balance.

Sora: Because it requires graceful yet powerful slashes.

Sora: So.......

Sora: I guess in order not for you to somehow not lose your balance if you made a mistake on your forms.....

Sora: Observe your surroundings. Anything that can help you gain ground......

Sora: After all, we must use the environment to our advantage as well, even if we are inside the enemy's territory.

Kanae: So......?

Sora: If you're fighting alone, find something that can allow you get an opening from your opponent.

Sora: Once you find that opening, I suggest that DO NOT go immediately after it.

Kanae: Huh? But why?

Sora: In order not for the enemy to realize that you already found a gap in their defense.

Sora: Look for any other openings and observe your environment once more.

Sora: I know long battles aren't really ideal as we may run out of stamina at some point......

Sora: But......

Sora: You got to observe your opponent. Habbits, mannerisms, techniques.....

Sora: Anticipate their attacks even further. This can actually be effective even without the Sharingan.

Sora: Don't just rely on your eyesight. Use your hearing, smell, and touch to predict the enemy's next move.

Sora: I would say that Inosuke would somehow be vital if you guys are fighting with him as his sharp sense of touch allows you to predict the opponent's surprise attacks.

Sora: But use your hearing as well, listen to the wind, to the sound whenever he attacks?

Sora: The sound of their weapons if they have one.

Sora: Smell them if they let out ominous smell when they get close.

Sora: Utilizing your other senses in battle, plus the environment.....

Sora: Also, if the enemy is using for example, fire, find a way to counter fire with water. If wind, find shelter in a rock. If ice, try to burn your surroundings, and spread the fire out.

Sora: Or use the heat whenever he exhale.

Sora: Also, we can use friction to create heat or fire.

---------------

Back to the present.

The reason why Kanae was able to adapt with Doma's freezing technique is because she used what Sora taught her.

Using the heat of exhaling breaths, secretly creating friction on the wooden floor......and also, Shinobu's poison.

Kanae: Shinobu's poison is clearly working now. I can see what Kanao really meant.

Inosuke: Beast Breathing, Second Fang!

Kanao: Flower Breathing, Fifth Form!

Inosuke: Kirisaki!

Kanao: Ada no Shukuyaku!

Doma: Blood Demon Art, Crystal Miko.

Doma creates ice sculptures of himself to block Inosuke and Kanao, while Shinobu was able to stab and inject poison on Doma once more.

As of now......

Shinobu already injected atleast 10 kilograms of poison and as observed by Kanao, the poison that was developed by Tamayo and Shinobu are starting to take effect.

As planned, Shinobu does the attack retreat strategy......to find another opening.

While Kanae is actually on the supporting role.

But they know that they must finish the fight immediately as no one knows how long Tamayo will be able to hold Muzan.

Doma: Blood Demon Art......

As the poison is now starting to take effect, Doma is in an act of desperation. The sculptures that Doma created shattered.

Inosuke: What the!?

Kanao: It's working! It's Shinobu-neesan's poison!

Kanae: Now!

Doma, in an act of desperation unleashes reckless attack.

Doma: Blood Demon Art, Rime - Water Lily Bodhisattva.

He creates an enormous giant Bodhisattva statue made out of hardened ice to stall the four of them and make a run for it.

Kanae: Incoming! Scatter!

The giant statue released deadly ice gusts from its mouth, and the four of them were just in time to jump and evade.

But the arms began to grab Inosuke, and when Kanae and Kanao attempted to break the arms, it was futile.

Shinobu: It's too damn hard.

Kanao: He's planning on running away!

Kanae: We can't let that happen! If he dissolves Shinobu's poison if he recovers it will be all for-

However........

As Doma is running.......a wall of black flames barred his path.

???: As if I'd let that happen.

Kanae, Shinobu, Kanao, and Inosuke gazed upon the source of the voice, and it is revealed to be none other than Sora.

Kanae: Sora......

Sora: Sorry, I'm late. Also, leave the giant statue to me.

Sora: You guys go after that bastard.

Sora jumps down from the platform as ethereal flames began to engulf him as he yelled.

Sora: Susanoo!

An ethereal humanoid manifestation appears and seems to be armored.

Inosuke: Woah!

Kanao: So this is......

Kanae: The Susanoo that Kanroji-san was talking about.

Shinobu: Amazing.......so this is the power of the Uchiha Clan.......

Sora faced the giant statue and the susanoo punched the statue and break it's head. This allowed Inosuke to break free from it's grip.

Doma: NOOOOOOOO! MY BEAUTIFUL CREATION!

The other four grabbed the chance to corner Doma, and the demon, still desperate creates the mini statues of himself.

He continues to desperately flee to another route.

Sora: !?

Sora decided to crush Doma's giant statue by slamming it with the Yata Mirror.

Sora: Now that's one down......

Sora gazes upon Doma who is slowly crawling away in despair, body already deformed due to Shinobu's poison.

Sora used Amatsumikaboshi to teleport in front of Doma, the latter just looked at the Uchiha.

Doma: I should've joined Akaza-dono in killing you.

Sora: That's your biggest mistake. You spent your sweet time playing around, and this is your downfall.

Sora: I already took you down once.

Sora: But this time......

Sora grabs Doma by the collar.........

Sora: This time, I won't be the one who'll behead you.

Sora: But first before you die......

Sora: Maybe one of these four will be the one fitting to finish you off, once and for all.

Sora used Kotoamatsukami to enter Doma's mind and to search for any memories that is related to the Kocho Sisters, Kanao, and Inosuke.

Sora already knew the Kocho Sisters' initial encounter with Doma before, so he didn't bother to look.

As for Kanao, he didn't find any memories that Doma is related to her memories. But when Sora found out about Inosuke, including his origins.......

How Doma even slandered Kotoha........

Sora returned back to reality.......

Sora: You bastard.....you really are the most despicable bastard that I ever knew........

Sora: You killed Inosuke's mother, and YOU will pay the ultimate price!

Sora: Inosuke, show this bastard what true hell is!

Sora throws Doma into the air, and as the others saw this, Inosuke didn't hesitate to finish the job. He takes a stance and prepares for the killing blow.

Inosuke: Beast Breathing, Third Fang!

Sora then focused on Inosuke's blades and set them on fire with Amaterasu's flames.

Inosuke: Woah!

Sora: Inosuke! Do it now!

Inosuke: YOSHAAAAA!

With a big leap......Inosuke decapitates......Doma's deformed head.

Inosuke: Kuizaki!

With Amaterasu's flames making contact with Doma.......it burned him completely before his body and severed head even landed on the ground.

Inosuke also lands to safety.........

While Sora, deactivates his Eternal Mangekyo Sharingan......

Sora: It's over.......

Kanae, Shinobu, and Kanao all rushed towards Sora whom the latter dropped on to his knees due to being exhausted in fighting Akaza earlier.

Kanae: Sora, you pushed yourself too hard.

Sora: Don't worry about me.......

Sora: Check on Inosuke.

The black flames on Inosuke's sword fades away.

Inosuke: What!? They disappeared!?

Shinobu checked on Inosuke and patched him up.

While Kanae on the other hand, helps Sora to sit down and to let him rest.

Kanae: So.....you came here after you defeated Upper Three?

Sora: I actually took the same route when I pushed Upper Three earlier.

Sora: But I waited for Tanjiro, Giyuu, and Kyojuro to recover......

Sora: I took some time to rest up as well.

Sora: When Giyuu woke up, he told me to go straight to Muzan.

Sora: I was on my way, but I noticed that you guys are now so close in winning, I just gave the final push towards victory.

Kanae: Fufu.

Kanao: Are you alright, Sora-san? Aren't you in pain?

Sora: I'm okay. Thanks for the concern, Kanao.

Sora: But, I'm more concerned about what is happening now.

Sora: No one knows how much Tamayo-san will be able to hold Muzan off.

Shinobu went to them while helping Inosuke with his injuries.

Shinobu: Then we'd better hurry but.....we also need to recover.

Sora: Not only that. We have to drag Muzan out of this fortress.

Sora: The light of the Sun won't reach here. As long as we are still inside of this dimensional fortress........we won't be able to defeat him.

Kanae: Can't your Amaterasu burn him?

Shinobu: You can instantly burn him with it, right?

Sora: No. He already know how Amaterasu is cast. He only needs to dodge at the right moment when I cast it or disrupt my own momentum through surprise attacks.

Sora: So, if i have to burn him with Amaterasu......I'll have to directly burn him at close range.

Sora: And the example is how Inosuke beheaded Upper Two.

Shinobu: You mean, we'll have to coat our swords with those black flames.

Sora: I won't recommend it. Muzan knows what Amaterasu's flames can do because nii-san used it when he fought Muzan.

Sora: Not to mention, those flames are hard to handle. Inosuke was lucky enough because he has a sharp sense of touch.

Inosuke: Hahahahah! I'm invincible!

Sora: Idiot! One wrong move and you'll be roasted until you turn into dust.

Sora: .......

Kanae: You got to rest for a while, Sora. We can't have you worn out when you fight Muzan.

Sora: .........

Sora: Then we can only hope that Tamayo-san will be able to endure much longer.

With this.....

Kagami delivered the message across of Upper Two's defeat in the hands of Sora, Kanae, Shinobu, Kanao, and Inosuke.

The others, especially the Hashira who are currently fighting Upper Rank demons......

On Mitsuri and Obanai's side who are battling against the newly installed Upper Four, Nakime.

Mitsuri: Amazing! Sora-san was able to help defeat two Upper Rank demons........!

Obanai: So the Uchiha must've been able to find a way in defeating two Upper Rank demons........

Obanai: No wonder why Oyakata-sama is trusts him.

Meanwhile, Gyomei, Sanemi, Muichiro, and Genya are currently fighting Upper One, with Muichiro and Genya severely wounded.

Gyomei: Sora was able to help us defeat two Upper Rank demons......

Gyomei: Then.....

Sanemi: We have to finish this fight as early as possible!

Genya: We need to help them in battling Muzan!

Muichiro: One way or another, we got to defeat Upper One!

Upper One, Kokushibo......a demon swordsman with six eyes......

Kokushibo: So Doma and Akaza fell by the hands of the Uchiha........

Kokushibo: Then, I have to finish all of you here, in order to prevent that thorn from reaching that man.

Gyomei: As if we'd let you!