Kagaya remained calm despite Muzan's presence!

Kagaya: So, you've finally come, Muzan. You are the one that our clan has pursued for over a thousand years. Amane, tell me. What does he look like?

Amane: He looks like he's in his mid to late twenties. But his eyes are light pink. And his pupils are vertical slits like a cat's.

Kagaya: I see. I expected you to come. I was certain of it. You must be terribly angry at me and the Ubuyashiki Clan. So I figured that you would come to kill me yourself.

Muzan: Indeed, I'm disgusted from the bottom of my heart, Ubuyashiki. For a thousand years, your clan has never known it's place, and has interfered with me constantly, but now I find its leader in this state. So loathsome and indescribably ugly. You already smell like a corpse.

Kagaya began to stand up as his bandages came apart.

Kagaya: I suppose I do. Six months ago, a physician told me I would die within a few days. And yet I still live. Even the physician is now at a loss for words. And it's all because I burn to defeat you, Muzan.

Muzan: And tonight that fragile dream shatters. You will die now.

Kagaya: You might not know it, but you and I are of the same bloodline. However, I suppose since you were born over a thousand years ago, we aren't closely related. I do not feel anything about that.

Muzan: What are you trying to say?

Kagaya: The clan ave birth to a monster such as you. And for that it was cursed. All of the children born to that house were weak and soon died. When the clan was about to die out, a priest offered counsel. He said a demon had come from the same bloodline. That we should dedicate ourselves to defeating him. If we did, the bloodline would survive. I took a wife from a family that had been in the priesthood for generations. After that, the children did not die as easily. But even then, no one in our clan lived past 30.

Muzan: Such pure nonsense turns my stomach. Has your sickness reached your brain? Those events bear no relation to this. But heaven has never punished me. It has forgiven my killing of thousands. And in a thousand years I have never seen the Gods or Buddha.

Kagaya: Is that how you view it? I see it differently. Muzan, what is your dream? For the land thousand years, what dream have your eyes been fixed upon?

Muzan noticed something was off.

Muzan: What's going on? I have the leader of the Demon Slayer Corps, which has vexed me so very much, right before my eyes, yet I feel no hatred. Actually-

He saw Kagaya's daughters playing around.

Muzan: There are only four humans in this mansion, Ubuyashiki, his wife, and two children. No guards or-

Kagaya: Shall I guess Muzan? I can fathom your heart. Your dream is an eternity. To be undying.

Muzan: That's right. And I will soon have it. I merely need to find Nezuko.

Kagaya: That dream will not come true, Muzan. You made a mistake.

Muzan: What?

Kagay: I know what eternity is. It's a human feeling. Only human feelings last forever. You are undying. For a thousand years, the Demon Slayer Corps have persevered. Many unfortunate children have died, but they are not gone. feelings are undying in their refusal to forgive those who unjustly steal the lives of their loved ones. And no one has forgiven you. Not in those thousand years. Furthermore Muzan, you have stepped on the tiger's tail over and over and invited the dragon's wrath. They have been sleeping, but you woke them up. And they won't let you escape. iling me will not harm the Demon Slayer Corps one bit. I myself am not that important. But you cannot understand human feelings and human bonds. Because if you die, all the demons will perish, right?

Muzan was angered by that.

Kagaya: AH, that got your attention, so I'm right?

Muzan: ENOUGH!

Kagya: Very well, that is all. I have said what I wanted to say to you.

Muzan then stepped forward.

Kagya: But may I say one last thing? I said that I myself am not that important, but that does not mean my death will be insignificant. Fortunately, the Demon Slayer Corps, and particularly the Hashira are fond of me. So, if I die, their determination will rise higher than ever before.

Muzan: Are you done talking?

Kagaya: Yes, I never expected you to listen this long. Thank you, Muzan.

Suddenly you sensed him.

(Y/N): Muzan.

In a matter of seconds...

(Y/N): EVERYONE! TO THE UBUYASHIKI MANSION! MUZAN IS HERE!

You talked to a bunch of the crows as they spread the word!

Crows: TO THE UBUYASHIKI MANSION! GET TO THE UBUYASHIKI MANSION!

Everyone ran at full speed!

Hashira: MASTER!!!!

You saw the mansion in a matter of seconds!

Ruby: THERE IT IS!

(Y/N): HANG ON KAGAYA!

But then the entire building exploded!

Yang: HOLY SHIT!

(Y/N): NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!

Everyone watched on in horror.

Mitsuri cried, Obanai and Shinobu were both speechless, Muichiro stepped back in shock, even Sanemi ... he had a look of horror on his face!

Kagaya, Amane, and two of their children had perished, with Muzan getting caught in the blast!

Muzan regenerated, heavily scarred!

Muzan: DAMN YOU UBUYSASHIKI! It seems that I underestimated you. You maniac! He made the explosion even more deadly by adding spike traps into it. Just to delay my regeneration. That means something is still coming. That shithead used himself as a decoy! His hatred and anger towards me was like a viper. It was coiling in that dead black stomach of his. I'm in awe at how stunningly he hid his murderous intent. Were his wife and kids aware of-

He then saw objects floating around him.

Muzan: This is- AAAAAAAAAAAAARGH!

He was impaled by giant spikes!

Muzan: A Blood Demon Technique?! These spikes are branching into my flesh so I can't pull them out! No matter! I'll just-

But then Tamayo appeared and stabbed him in the chest!

Muzan: TAMAYO!! These Blood Demon Spikes belonged to the man who got turned into a demon in Asakusa. What is she-

Tamayo: I got you now Muzan! What I injected into you was a drug that turns demons into humans!

Muzan: Impossible!

Tamayo: Oh but I have. The tables have turned!

Muzan: You are one stubborn woman, Tamayo. Who killed your husband and kids? Was it me? Not at all. Nobody but you! You ate them!

Tamayo started to cry as she screamed.

Tamayo: IF I KNEW THAT WOULD HAPPEN I WOULD HAVE NEVER AGREED TO BECOME A DEMON! ALL I WANTED WAS TO NOT DIE FROM MY DISEASE! I JUST WANTED TO SEE MY CHILDREN GROW UP!

Muzan smirked.

Muzan: Then you killed a whole bunch of humans after that. Was that an illusion? I noticed you had a lot of fun with it!

Tamayo: Yes, I killed many people after falling into the depths of despair. AND THAT'S WHY I'M WILLING TO DIE HERE!

At that moment Gyomei arrived and took off Muzan's head with one blow!

Gyomei: As I thought. It's just as Master predicted.

Muzan regenerated.

Gyomei: He won't die no matter how many times his head is cut off. He s unlike all the demons we have faced until this point.

Muzan: BLACK BLOOD TECHNIQUE: CHAIN OF THORNS!

Muzan unleashed a bunch of thorn vines towards Gyomei, but the Buddhist Hashira stood his ground!

Gyomei: STONE BREATHING: THIRD FORM: IGNEOUS REFLECTION!

He deflected them all!

(Y/N): MUUUUUUUUUUUZZZZZZZZZZZZAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAN!!!!

You charged in!

(Y/N): I'LL MAKE YOU PAY FOR EVERYTHING YOU'VE DONE YOU DEMONIC PIECE OF SHIT!

Muzan: And you're (Y/N) (L/N)? AM I SUPPOSED TO BE AFRAID OF ONE MEASLEY HUMAN?!

(Y/N): NO! YOU SHOULD FEAR ALL OF US!

Team RWBY surrounded him.

Ruby: THIS IS FOR TANJIRO'S FAMILY YOU MONSTER!

Weiss: You won't escape from us!

Blake: I hope you know hell, because you won't escape from it.

Yang: How about I blow your head off 100 million times asshole?!

Tanjiro: It's over for you!

Muzan growled more as he saw Tanjiro and then all of the Hashira joined in!

(Y/N): I always have a backup! And they're all as pissed off as we are!

You all prepared to attack!

(Y/N) and Tanjiro: HINOKAMI KAGURA-

Ruby: FLOWER BREATHING: FIFTH FORM-

Weiss: ICE BREATHING: SECOND FORM-

Blake: SHADOW BREATHING: THIRD FORM-

Yang: TIGER SHATTER FIST!

Muichiro: MIST BREATHING: FOURTH FORM-

Shinobu: INSECT BREATHING: BUTTERFLY DANCE!

Obanai: SNAKE BREATHING: FIRST FORM-

Mitsuri: LOVE BREATHING: FIFTH FORM-

Giyu: WATER BREATHING: THIRD FORM-

Sanemi: WIND BREATHING: SEVENTH FORM-

As soon as all of you could attack, suddenly doors opened up!

Muzan: HAHAHAHAHAHAHAHAHAHAHAHA! DID YOU PITIFUL HUMANS THINK YOU COULD CORNER ME?! SEND ME TO HELL YOU SAY?! THAT'S WHERE YOU'RE ALL GOING NOW! PATHETIC DEMON SLAYER SCUM! YOU ALL DIE TONIGHT!

(Y/N): NO MUZAN! YOU DIE!

You all fell down into the Infinity Castle!

And then-

Kokushibo: They're here.

Doma: Oh, Nakime. Did you bring some dinner for us? Perfectly.

Doma licked his lips pervertedly.

Akaza sensed you too, and a big smile came across his face.

Akaza: (Y/N). Perfect. THIS IS GOING TO BE THE GREATEST FIGHT OF MY LIFE!