You and Team RWBY arrived at a new location unlocked on the DS! 

Ruby: So, it said Mt. Natagumo? 

(Y/N): Yep. And apparently we're in the Taisho Period of Japan. 

Blake: Right, this looks ... interesting. 

You all begin to explore the area as the vibration of some threads give way to someone nearby. 

???: So, more intruders? Those damn Demon Slayers are bad enough. No matter what. I'll just have Mother dispatch of them. 

Back with you all ... 

Blake overheard the sound of wailing and moaning in pain. 

Blake: PEOPLE ARE IN TROUBLE! THIS WAY! 

Weiss: Now? Why does it seem that we're running into people in trouble whenever we start an adventure? 

You all ran to see people in black uniforms injured. 

???: Please ... kill ... us. 

Ruby: Hey, what's going on here? 

???2: Don't ... come ... any ... closer. 

(Y/N): What do you mean? What's- 

Suddenly they stood up and pointed their swords at all 5 of you. 

(Y/N): Huh? 

You sensed that they were being controlled. 

(Y/N): They're being controlled by threads! 

You cut them down, and healed them with Mimic. 

Yang: Nice one! Okay, what the hell is going on? 

???: Demons. There are demons up here. 

Nearby... 

Spider Demon Mother: So, my puppets have been freed. Guess I'll have to use that one. 

She used the threads attached to her fingers to control a headless body with blades for arms! 

And it went for all of you! 

(Y/N): AGH! 

You dodged it. 

Ruby: WHAT THE?! THAT BODY! IT'S HEADLESS AND MOVING! 

(Y/N): The puppet user is nearby! 

Blake: I'll take it out. You guys deal with that. 

Blake dodged the attacks of the headless puppet and went to find the puppetmaster. 

(Y/N): Hmm ... we need to stab the vitals. That's the only way we're going to kill it! 

Ruby: Okay! Now- WHOA! 

It sped forward and sliced at Ruby, but she used a Shadow Clone to protect herself! 

Yang then punched it in the stomach as Weiss froze the legs, and then- 

(Y/N): AVAN STRASH! 

You cut it in half! 

Spider Demon Mother: That ... was my most powerful puppet. How could I- 

Blake then appeared. 

Blake: So, you're the puppetmaster. 

Spider Demon Mother: This is it. Give me ... sweet release. 

She waited for the killing blow. 

Blake: She ... wants to die? I ... I guess I'll grant it for you. 

Blake killed the demon with a decapitation. 

Blake: If you were suffering, I hate to imagine what hell you were enduring. 

Meanwhile... somewhere else in the mountains... 

???: ARGH! WHERE THE HELL DID TANJIRO AND INOSUKE RUN OFF TO?! I'M FUCKING LOST! 

Zenitsu Agatsuma (A Demon Slayer who is a massive coward! Usually hits on beautiful women! Master of the Thunder Breathing, though only when he's unconscious!) 

Zenitsu: I SWEAR IT STINKS AROUND HERE! I MIGHT JUST CRY! 

Then he heard a noise. 

Zenitsu: WOULD YOU SHUT UP ALREADY?! 

Zenitsu: AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGH! HUMAN HEAD! 

He runs off in fear. 

Zenitsu: WHAT THE HELL?! WHAT THE HELL?! THIS HAS TO BE A DREAM! IT HAS TO BE! IF YOU'RE JUST A DREAM I'LL WORK HARDER! I'LL PLOW THE FIELD AND EVERYTHING! I'LL JUST WAKE UP WITH NEZUKO IN MY ARMS! WAKE UP! WAKE UP! 

But then he ran into a shack with hanging corpses. 

Zenitsu: What is going on here?! Is that house floating? 

Then a creature came out of it. 

Zenitsu: AAAAAAAAAAAAAAAAAAAAAGH! 

Spider Demon Brother: HAHAHA! No use in running now! You're already dead! 

Zenitsu: STOP TALKING TO ME! I CAN'T STAND GUYS LIKE YOU! 

Spider Demon Brother: Sheesh, look at your hand, dumbass! 

Zenitsu saw his hand was swelling. 

Zenitsu: AGH! 

Spider Demon Brother: That poison in your body will turn you into a spider! In just a couple of hours, you will become my slave! 

He then brought out a watch. 

Spider Demon Brother: When this watch reaches 1:00, your hands and feet will tingle. When it reaches 3, you'll feel dizzy and nauseous, and when it reaches four, you'll lose unconsciousness! And then- 

Zenitsu: NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO! 

He climbs up a tree to hide. 

Zenitsu: SHUT UP! STOP TALKING! NO MORE! 

Spider Demon Brother: There's nothing to be afraid of. Once the poison runs throughout your system and you become a spider, there will be no more of your mind. 

Zenitsu: I DON'T WANT THAT SHIT! WHY DON'T YOU GET THAT?! I DON'T WANT TO BE LIKE THAT! 

Flashback... 

https://youtu.be/30pxMkg7C5Q

Play from 0:23-end... 

Back to Present... 

Zenitsu: I TRY AS HARD AS I CAN TO CHANGE! BUT NOW I'M GOING TO BECOME A MONSTER WITHOUT BETTER HAIR?! I CAN'T TAKE THIS! 

Spider Demon Brother: What is it with this guy? 

Zenitsu then saw that his hair was falling out. 

Zenitsu: It's falling out? He never said about- 

He then collapsed. 

Spider Demon Brother: What's up with this guy? Isn't he supposed to be a Demon Slayer? What a coward. 

And then- 

Zenitsu: THUNDER BREATHING: FIRST FORM: THUNDERCLAP AND FLASH! 

Zenitsu charged at the Demon, and tried to slash at him, but- 

Spider Demon Brother: POISON SPUTUM! 

He shot a poisonous substance, but Zenitsu dodged by twisting his body. 

Spider Demon Brother: Huh? What did he just- 

Zenitsu: Gramps. I'm slowing down. 

Flashback... 

Zenitsu was training with his fellow disciple. 

???: JUST GET LOST! LOSER! I'm not going to waste my time with you! 

Zenitsu: But Gramps- 

The man threw a peach at him! 

???: Don't call him Gramps! Sensei was a Hashira! He reached the highest rank in the Demon Slayer Corps! It's a rare honor to receive instruction from a former Hashira! Sensei is completely wasting his time on you! You're just an eyesore! 

Back in the present... 

Zenitsu: No one ever expected anything of me. I spent my whole life alone as I protect others. Even a humble future of making others happy. No one dreamed of even that. But Gramps, he kept on scolding me again and again. I ran away, but he kept on dragging me back. He never gave up on me. 

Spider Demon Brother: NOW! INJECT THE POISON! 

More Spider Demons go for Zenitsu, but he kept moving, and- 

Zenitsu: THUNDER BREATHING: FIRST FORM: THUNDERCLAP AND FLASH SIXFOLD! 

He decapitated the demon! 

Spider Demon Brother: D-DAMN IT! 

Zenitsu fell down on the structure. 

Zenitsu: Time ... to dream. 

Meanwhile... 

???: Did that sound like Zenitsu's lightning strike? 

Tanjiro Kamado (A new recruit in the Demon Slayer Corps! He seeks to turn his sister Nezuko back into a human! Very friendly and nice guy! Doesn't have a single bad bone in his body!) 

Tanjiro: Inosuke, we should probably- 

???: BAH! DO WHAT YOU WANT! 

Tanjiro: Maybe you should go, you're badly hurt and- 

???: NO I'M NOT! I'M FINE! 

Inosuke Hashibira (This idiot was raised by boars when he was a child! Yes, he does look fine underneath that mask! Uses Beast Breathing!) 

They then notice another demon nearby. 

Inosuke: DEMON! I'LL SLICE YOU INTO RIBBONS! 

Tanjiro: INOSUKE WAIT! 

???: AGH! FATHER HELP ME! 

Just then a giant monster appeared! 

Spider Demon Father: STAY AWAY FROM MY FAMILY!