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The demon of the future (KNY x Fem! BNHA Reader)

Summary:

"It doesn't matter what timeline I'm in, I'll be a hero that will save people as much as I can!"

Ubuyashiki (Y/n), the great-granddaughter of Ubuyashiki Kiriya with a demon quirk got sent back in time by a time villain, to when demons still exist.

How will she get back? What will she do about the man-eating monsters that are roaming around Japan now?

 

✨ A Kimetsu no yaiba x BNHA reader insert

✨ Will contain spoilers for the manga, so read at your own risk

✨(VERY) Slow updates

✨ Multiple endings at the end

 

Also available at Quotev and Wattpad!

 

Hope you enjoy reading!

Chapter 1: Introduction ✿

Notes:

(See the end of the chapter for notes.)

Chapter Text

𝔽𝕚𝕣𝕤𝕥 𝕟𝕒𝕞𝕖: (Y/n)

𝕃𝕒𝕤𝕥 𝕟𝕒𝕞𝕖: Ubuyashiki

𝔾𝕖𝕟𝕕𝕖𝕣: Female

𝔸𝕘𝕖: 13 - 14

𝔹𝕝𝕠𝕠𝕕 𝕥𝕪𝕡𝕖: O-

 

【Appearance】

ℍ𝕒𝕚𝕣: (H/l) (Hair length), (H/s) (Hairstyle), (H/c) (Hair Colour) hair with a black streak on her bangs (change to white if you have dark coloured hair)

𝔼𝕪𝕖𝕤: Pale purple with black swirls, and white pupils

ℂ𝕝𝕠𝕥𝕙𝕖𝕤: Usually in a(n) (F/c) haori with wisteria designs on it, and a wisteria pin that has a white ribbon with purple flame patterns on her hair.

 

【Quirk】

ℚ𝕦𝕚𝕣𝕜 𝕟𝕒𝕞𝕖: Demon

Her quirk works like how a demon works in the olden days.

✨ She can heal fast, but the bigger the wound, the longer it will take her to heal it. She could also heal internal wounds and bones

✨ She can regenerate body parts, like her arms, legs, even her head. If she regenerates too much or too fast, the regeneration process will be a lot slower, and she will need to sleep if she wants to regenerate fast again (the longest she slept was a month). The more she practices with it, her regeneration will be a lot faster, and she doesn't need to rest that much.

✨ She's a lot stronger than any other person! Just like a demon, she'll be faster, and stronger than any normal human!

✨ She can't be killed by a nichirin blade! It's because of her regeneration and the fact that she isn't a demon

✨ She can't turn someone into a demon! That's because she has normal human blood! Just because her quirk is a demon, doesn't mean she has demon blood!

✨ She can reattach her body parts, but the parts need to be in one piece. If it's destroyed, she can't reattach it and would need to regenerate. There's no drawback.

✨ She can perform blood demon art, but using too much of them will make her lose a lot of blood. Her demon art consisted of:

Ø 𝔹𝕝𝕠𝕠𝕕 ℍ𝕒𝕟𝕕𝕤: When her blood touches the surface, hands made out of blood will sprout out from it, it can be used as offence or defence. It can also take someone to another place, as long as she has been in that place

Ø ℝ𝕖𝕤𝕥𝕠𝕣𝕚𝕟𝕘 𝕓𝕝𝕠𝕠𝕕: she could heal any wound that can be touched by her blood, as long as she could put her blood on it, she could restore it. Unfortunately, if that person dies, she can't revive them. If she uses a lot of her blood, the wound will heal a lot quicker. She can fix organs if it's out in the open. For poisoning, she will need to get her blood inside the person, by either making them drinking it, or she gets her blood into their bloodstream.

Ø ℍ𝕖𝕒𝕝𝕚𝕟𝕘 𝕓𝕒𝕣𝕣𝕚𝕖𝕣: She can make a tall barrier by spreading her blood on the ground, but if she scattered her blood around her / a person, it will make a barrier that can slowly heal wounds, the barrier can slow down poison or venom reaction but won't really take it out of the human system. Like its name, it also doubles as protection.

 

【Personality】

(Y/n) is a kind and chill person, she will put others first before herself, sacrificing herself for other's sake.

She has a chaotic good energy

She's a little bit awkward and tends to be very polite when you meet her for the first time, but once you've befriended her, she would be more relaxed, she will support you through thick and thin, and she will try to be best god damn friend you will ever have.

She rarely gets angry, but once she is, a single glare from her is enough to send chills down your spine.

 

【Small Facts】

✨ She's very good with children, considering she has a set of younger twins to help take care of. So she won't have a problem making children happy again.

✨ She will wear her haori over anything she wears, even school uniforms.

✨ Her favourite subject is history, especially about demons, and slayers. Fun fact! She actually practices her blood demon art from books about demons!

✨ No one in her family has the same eyes like hers, except for her great grandfather

✨ She realized she could use blood demon art when she accidentally got her blood on her little brother's wound, she saw when her blood dropped on it, and it immediately heals. After that experience, she began to study demons and their blood demon art.

✨ Her usual weapon is a retractable staff, she always keeps it in her pocket

✨ She always keeps a pocket first aid kit that has the necessary items to help her close up a wound

✨ She can stand under the sun, but if she's doing activities under the sun for too long, her body will overheat, and she will get a nosebleed. Her body will get used to the heat if she keeps practising under the blazing sun (she was forced to practice at noon in the training camp arc)

✨ Her father died when she was six years old, and her siblings a few months old. He died because of a villain attack.

 

【Keys】

(Y/n) = Your name

(H/c) = Hair colour

(E/c) = Eye colour

(F/c) = Favorite colour

(F/f) = Favorite food

(H/s) = Hairstyle

(I/h/c) = Inverted hair colour

(M/n) = Mispronounced name

(B/w) = Black or white (for the streak on her bangs)

 

A reminder, that this book will contain manga spoilers, so if you haven't read the manga, please read it at your own risk

Notes:

✨ Spotify playlist link:
Season 1
https://open.spotify.com/playlist/4ilQT87qnO6WgeRzq5TIn6?si=f27ac43069234d3d

✨ Wattpad link:
https://www.wattpad.com/story/246761290-the-demon-of-the-future-kny-x-fem-bnha-reader

✨ Quotev Link:
https://www.quotev.com/story/13572437/The-demon-of-the-future-KNY-x-Fem-BNHA-reader