I'm gonna be the only Hashira with a Bankai

Defeating the Demon King

3rd POV
The battle raged on as Hashira battled with all of their might to defeat Muzan, but none have come close to damage him significantly. Except for Gyomei and Obanai, with the 2 gaining the abilities to increase their power and understanding of Muzan's body. With the arrival of the last pillar to join the heat of battle, things were going the way of the demon slayers. Even after the death of Yoriichi the creator of sun breathing, the presence of Shika indulges fear in the nigh immortal being.

Shika's POV
With the help of Yushirou's talisman I was able to do the most damage out of all the pillars so far with my speed and the power of invisibility. Though he may have caught into Inosuke, Zenitsu, and Kanao, in terms of speed Muzan and I are nearly equal. Though I have not been struck with his attacks so far even relaxing for a bit will leave me open and let my guard down. Though after a few clashes, it became a standstill between the both of us, with all other Pillars injured and exhausted, along with the their apprentices. But the second round became between the two of us as my Bankai clashed against all of his whips to stay alive, but I've been noticing that he's getting slower, I only need him to be slow enough for Tanjiro to compete and finish him off. Before all of my hits had a low chance of hitting, but now most of them make contact with him now, which means he can't dodge a fully powered Getsuga Tensho. Backing up a Bit, I sliced my finger letting the blood leak, charging my spiritual pressure to nearly the max, firing off a Getsuga Tensho along with using a Gran Rey Cero Blast.

"Gran Rey Cero-Getsuga Tensho." I said.

The attack obliterated Muzan's body into near nothingness, his body nearly destroyed leaving only his Head and upper body remaining. This was the perfect moment as Tanjiro got back into battle finally using his Sun Breathing technique to finish Muzan off who's cripple at the moment. I watched as Tanjiro's attacks nearly connect as Muzan can barely dodge them while regenerating as is, but as soon as Muzan gain back into power, Tanjiro started losing consciousness little by little performing. I stepped in to protect him, he is still getting slower but he is still ferocious to be careful around, but Iguro came in time to get Tanjiro to safety for a brief moment before joining back into the fight, but as soon as Tanjiro was saved, a crow spoke of Dawn arriving in 40 minutes causing Muzan to flee, I ran over to pick up a sword while marking it, I threw just enough to pass him, teleporting to it I was in front of Muzan, charging my spiritual energy into a fully powered Getsuga Tenshou. It was a direct hit but I could no longer see Muzan's body due to the destructive power of it and the dust and debris from the aftermath of using it. After the dust settled I still couldn't find Muzan but I rated in my toes just in case he launched a counter attack on me. Only for Iguro to find Muzan and pin him down with ease, he knocked Iguro off him and attempted to split but it didn't work, this caused him to vomit up blood. Tamayo drug will definitely work in my favor here, Muzan was standing still until a flash of pressure hit Tanjiro, Obanai, and I, sending both of us back, especially me into a nearby building. Inosuke and Zenitsu rejoin the battle to protect Tanjiro, slighty proceeding is doing some damage since Muzan, can no longer run or barely move as a matter of fact. Attempting to help the others in I felt my body become a little numb from that shockwave, I waited and watched them right on, He even hit Inosuke with the shockwave but Tanjiro stepped in and saved him at the last minute while trying to perform sun breathing forms, kneeing he wouldn't hold on for long, as Muzan began a counterattack I had to step in to save Tanjiro.

"Hiraishin no Kokyū, Ichi no Kata: Hiraishingiri(translation: Flying Thunder God Breathing, First Form: Flying Thunder God Slash)."

With the efforts of Inosuke the attack connected, in this dire need everyone started attacking Muzan, Zenitsu strikes Muzan and almost suffered the consequences had not Tanjiro stepped in, while Kanroji grabbed hold of Muzan's arms and ripped them off. Sanemi stepped in with Tanjiro pinning Muzan against a wall, as Muzan was gonna eat Tanjiro, Obanai stepped in the way. From the distance the sun was rising and to Muzan desperate need to escape he unleashed a shockwave, blasting back except Tanjiro. Tanjiro in his desperate need to turn his blade red in order to defeat Muzan, but Giyu stepped in giving his strength to Tanjiro who needed it the most, As the sun hit Muzan's face showing that signs that his death is near he began encasing himself in a armor of flesh similar to a baby. I acted fast and pulled both Tanjiro and Giyu out of there while Muzan tried to escape towards the shade. The rest of the demon slayer Corp did all they could to try to prevent Muzan trying to stop him in his tracks with the rest of the available pillars attacking him with Gyomei and a bunch of Kakushi helping him but they can't hold him for long.