RuiKasa Oneshots

Demon Slayer AU

This is literally a copy and paste from my first one shot book, so having to go through the names and change them was a big hassle 😭😭

I used some characters from Colourful stage and Vocaloid, I think most of them are from Demon slayer but idk 😭

Life as a Hashira isn't the best, well if you're Tsukasa, his family was killed by these creatures called demons, from that fateful day he sought to do whatever in his power to kill every demon he comes across, that was until today

Tsukasa was sent on a mission to this family house on top of a mountain, he was running through the woods making his way up towards the house when he saw a boy with dark read hair and a girl with similar coloured hair fall off the edge of a cliff, he stopped for a moment wanting to see what would happen, he watched as the boy jogged over to the girl and watched the blanket that was covering her fell onto the ground and noticing she was covered in blood

The boy placed his hands on the girls shoulder trying to say something to her when she suddenly pounced on him knocking him down

Tsukasa crouched and moved his nichirin blade out of its sheath slightly, waiting for what would happen next, he watch as the boy held a hatchet in her mouth preventing her from hurting him

He watched carefully, his eyes analysing the girls movements and watched as she grew bigger, this confirmed his suspicions and he ran towards the two, not seeing the girl beginning to cry, and jumped to get a better hit at the demon girls neck

The boy seemed to have seen this and flipped the two over causing his ponytail, that was tied in his hair, to be chopped off, Tsukasa then kicked the girl over to a tree as the boy held onto her taking the hit and hurt his back on the tree

"Why are you protecting it?" Tsukasa asked sternly

"She's my sister! She's my younger sister!" The boy yelled back

"You call that thing your sister?" Tsukasa asked again narrowing his eyes

Tsukasa launches himself at the two, ready to strike, as the boy moves to protect his younger sibling, but realises she is no longer under him, when he looks up he sees Tsukasa holding her in the distance by the scruff of her clothes

"Nezuko!" The boy yelled beginning to stand up

"Don't move." Tsukasa said coldly but with a face that expressed no emotion

the boy kneeled back down tearing up slightly, not knowing what to do

"My job is to slay demons" Tsukasa stated clenching his blade in one hand "Needless to say, I'm going to decapitate your sister." He said bluntly

The boy looked shocked by Tsukasa's statement and hesitated to say anything

"Hold on! Nezuko hasn't killed anyone!" The boy started "Back at my house, there was another scent I'd never smelled before! That's probably the one who killed my family! It wasn't Nezuko! I don't know why she turned into something like that, but... but still...!" He continued to yell

"It's quite simple." Tsukasa started with the same monotone voice and expressionless face "because her wounds were exposed to demon blood, she turned into a demon. That's how man-eating demons multiply" he explained

"Nezuko would never eat humans!" The boy exclaimed

"You gotta be kidding." Tsukasa muttered under his breath "just now, you were about to be devoured"

"You're wrong! I'm sure she knows who I am!" The boy yelled "I won't let her hurt anyone! I'm going to turn Nezuko back into a human! I swear I'll heal her!"