I woke up due to Sanemi dropping me to the ground.

I looked around and the battle had already started, we were pretty late. 

There was a man with white hair. mouths on his limbs, and tentacles sticking out of his back.

Muzan, I had to get up and help them.

I grabbed my katana and stabbed it on the ground to bring myself up. My arms were fine, my eyes were more clear, and my legs were shaking. 

There was no time to worry about my injuries, Muzan was right here, and we needed to kill him.

I took deep breaths and focused on easing the pain. 

Looking around, I wanted to observe my surroundings but there was no time for that.

Giyu was in a state of shock and he was about to get cut.

[...Snow in the Blizzard!]

I sprinted over and deflected the attack just in time.

"Don't space out Giyu, we have a man to kill." I said.

Giyu snapped out of his trance and grabbed his blade.

[...Dance of the Swift Current!]

(Author POV)

Tokan, Muichiro, Gyomei, Sanemi, and Iguro started attacking.

'Before dawn, Muzan's head must be cut.' were their thoughts.

Suddenly, a cat with syringes appeared on top of them and struck the hashiras with the poison.

"What's this?" asked Muichiro.

"I have no idea what the heck just happened but that stray cat just saved my life." said Sanemi.

"Damn that woman Tamayo, even in death she continues to get in my way."

"Don't struggle in vain! Just die already, obsessed freaks!" yelled Muzan.

A bunch of attacks suddenly came from Muzan creating a bunch of large holes on the ground.

They jumped just in time to avoid the attack, Iguro was in the air with a tentacle coming at him.

"Iguro!" yelled Giyu.

Before Iguro was cut, the attack instead was deflected.

(Tokan POV)

Strange, what deflected Muzan's attack?

I looked closely at the severed section, with my keen eyesight, I was able to make out the damage.

The blade wasn't sharp, one was full with edges, and it clicked me.

Kanao, Zenitsu, and Inosuke was here but I couldn't see them, it was probably a technique.

[...Flowing Fractures!]

[...Safflower Robe!]

[...ThunderClap Flash!]

[...Tightening Coil!]

Multiple slashes came down at Muzan. 

Using his tentacles, he was able to deflect most of them. Though something caught my eye, Iguro's blade was shining, heat was coming off of hit. Whenever his attacks would hit Muzan, it would take longer for him to regenerate.

Was this something about the Sun Blades?

Instead of heating my sword, I decided to freeze it. 

[...Frozen Hatred!]

The atmosphere surrounding me started to turn cold, there were ice and snow appearing. My body temperature was turning colder and colder, soon enough my sword felt light. It began to turn transparent, it was a theory to test out.

While the others would attack him on his main parts of his body, I decided to a sneak in attacks.

While Muzan was distracted, I loosed my body and ran at him. I was able to cut the side of his stomach and like I thought, the wound was regenerating more slowly than usual.

The colder it was, the stronger I felt. Looking at a reflection of someone's blade on the ground, the marks were covering my neck and nearly my entire face. Now was not the time to to be worried about my appearance.

The other hashiras had started their attacks and I synced in with them.

With their red blades and my freezing blade, our attacks was weakening Muzan.

My eyes entered transparent world again, he had multiple brains and hearts.

This was why severing his head wouldn't work, his heart and limbs are constantly moving, making them have no set black and more difficult to hit.

"Focus on the body! Can you see through his body?" asked Gyomei.

I see, he can see through his body too. This was going to be more advantageous to us.

BOOM!

Suddenly an attack came at a speed a normal human can't see.

Before the attack could hit me, the world was in slow motion again. I was able to deflect it but the others were sent flying into the buildings. I silently prayed in my head that they would stay alive and apologized I couldn't help.

Kanao was going to get hit but we had different ideas.

[..Shining Ray of Grace!]

[...Frozen Love!]

A spiral fire and a horizontal slash of ice cut Muzan's arm leaving it in two sections.

"Tanjiro and Tokan." said Kanao.

"Took you long enough." I said.

"Sorry Tokan-san, let's end Muzan shall we?" asked Tanjiro.

"You're right." 

I turned my attention to demon,

"Let's put an end to this, Muzan." I said.

[...Waltz Scorching Crimson Mirror!]

[...Fire Chariot!]

I see, constantly and linking the attacks to make it more deadlier. 

Thank you Tanjiro, I've figured out another way to destroy his brains and hearts.

We started syncing our attacks yet constantly using our forms to link them together.

Frost Breathing and Sun Breathing were similar in one aspect, it was related to dancing.

By constantly breathing and dancing, you will never go cold.

Half-way through linking the attacks, my body was starting to hurt. Yet I couldn't falter, I needed to kill him if it was my last mission.

After killing my family, there was no way I would give up the chance to kill this man.

There was about an hour until dawn, we needed to atleast last until that long.

[...Turbulent Freeze!]

I was on the eighth from, cuts were appearing on my body. The damages done on Muzan's body were still there, he was weakening.

[...Blessing of the Blackened Ice!]

Ninth form completed,

[...Frozen Love!]

Tenth form! There was one more form to go, the eleventh form was the transparent blade. The twelfth form was the future insight.

[... Insight of Snow!]

All twelfth forms were connected, I saw tons of futures in 3 seconds.

I was able to defend all the incoming attacks because of what I saw,

now I had to repeat the forms faster and more accurate.