Dawning on new roles!

Demon Slayer SWAP AU

After her older brother's ankle is sprained, Nezuko Kamado manages to convince him for her to go sell charcoal on his behalf. Sadly, she returns home to find her family massacred and her brother, Tanjiro, turned into a monster. Now she embarks on a journey to cure him and stop the demon who changed her life by becoming a demon slayer!

Concept Art for a possible "Ship Swap" AU

♥️UNDERTALE × Demon Slayer 🎴

Back on my UT/DR mood, this time I'm enlightened by a good friend's ( @sillylittlegenderfluidthing ) AU at the Red Wisteria Discord server, which I was granted permission to share. The broad concept is that the demons from KNY take on the roles of the various monster characters from UT, with Tanjiro being the fallen human.

Here are the roles they devised, with a few additions from yours truly:

MT. EBOT 201X -> MT. FUJIKAZANE 192X. Mountain setting where inhuman creatures are trapped.

Frisk -> Tanjiro. The human protagonist that has the capability for great empathy and mercy, but also stern vengeance and violence.

Flowey/Asriel -> Kokushibo/Michikatsu. A powerful entity that is detached to the world around him, eventually projecting another identity onto the recent fallen human.

Toriel -> Tamayo. An old, benevolent maternal figure stricken with guilt who attempts to protect the fallen human from her own kind.

Napstablook -> Hantengu. A pessimistic, defeatist and upset spirit.

Sans -> Gyutaro. The older brother whose cynical and sarcastic attitude hides his true strength, he cares about little outside of his sibling.

Papyrus -> Daki/Ume. The exuberant younger sibling with high self-esteem that strives for greater popularity and prestige.

Undyne -> Akaza/Hakuji. A strict and resilient individual that values strength above almost all, but still steadfast to those he cares for.

Alphys -> Nakime. A mostly stationary woman who has 'eyes' watching all across the realm, responsible for maintaining a location.

Mettaton -> Gyokko. A flamboyant entertainer with a passion for his art willing to do anything for acclaim.

Asgore -> Muzan. The long-lived king of the realm who plans to attack humanity due to a vendetta, yet does not strive for change.

Fallen Human/Chara -> Yoriichi. The ghost hauting the narrative that is mistaken for the protagonist.

If you'd like to read more about my "Demon Coexistence AU", please let me know. I'm thinking of sharing (someway, idk how) what I've written for the AU, so you fellas may suggest additions!

Here is some general information about the AU so we can have some common ground:

• It's set in a modern, contemporary world to our own. That way we can focus on the demon stuff without having to contextualize it in the Taisho Era.

• Demons are a natural occurring phenomena. Once a person hits puberty, they can start developing demonic traits, eventually becoming a fully fledged demon. Only a small percentage of the population are predisposed to this (something like 0.2%)

• Otherwise all traits regarding demons remains the same as KNY canon (human flesh consumption, overall abilities, weaknesses to sunlight, etc...)

• In a treaty made long ago, demons do not actively prey on humans while humans provide sustenance to demons via corpses and blood donations.

• A branch of armed forces enforces, known as [NAME PENDING], enforces the treaty between men and demons. Composed of both human officials and high-ranking demons, its purpose is, among other things, to detain Deviant Demons who break the law.

• As a general rule, all characters who became Demon in canon are demons in this AU, while humans characters remain the human.

The following characters have written, somewhat thought out backgrounds by me: Rui Ayaki, Hakuji "Akaza" Soyama, Ume "Daki" Shabana. ( I also have vague plans for Nezuko Kamado and Michikatsu "Kokushibo" Tsugikuni, though not in writing yet...) Feel free to ask about them if interested.

Once upon a dark moon, a lonesome swordsman encountered a phantom of the past. Kokushibo, the fallen samurai turned demon, met a young boy by the name of Tanjiro Kamado, an almost doppelganger of his long deceased twin brother he loathed. Subsiding his hatred, the strongest Upper Moon of the Twelve Kizuki decided to conquer his emotions -the complex he still has with his prodigious twin- via exposure therapy with the child.

In the secluded temple grounds of a cult known as Paradise Faith, the leader and prophet of the twisted religion, though hollow inside, grows curious at one of his followers and her child. Douma, Second highest-ranking Upper Moon serving under the Demon King, begins to lern about Kotoha Hashibira and her piglet, Inosuke, fiding his cold heart to kindle ever so slightly.

In the bustling Red-Light Entertainment District of Yoshiwara, a highly renowned courtesan -an oiran- known as Warabihime prowls the currupt district as her true self, Daki, a vain demon, alongside her brother, Gyutaro. In one of her sporadic hunts, she encounters a street rat whose conditions and appearance hearkens back to memories long forgotten, so, conflicted, she fostered the homeless child named Zenitsu.

These coincidental encounters lead to drastic changes in destiny, but will it be for the good of humanity or for its detriment?

 A long time ago, Mitsuri was energetic an energetic girl whose dream was to find love and get married. Unfortunately, most suitors found her outgoing personality to be immature and not proper for a lady. The only person who ever showed interest in her true self was a mysterious boy with heterochromia.

 The boy's (Obanai's) life was riddled with trauma, his mother and cousins would constantly mistreat and insult him, causing him to develop a strong inferiority complex. One day he ran away from home and met an optimistic girl by the name of Mitsuri, who he instantly became infatuated by.

 The two became friends and slowly developed feelings for each other, however their difference in status prevented them from being in love. time and time again Obanai would ran away from home to meet Mitsuri, unbothered by the punishments his mother would give him once he returned.

From here on I have less written down, but my rough idea is to have uit so, one day, Obanai's family discovered where he ran to, robbing and murdering Mitsuri's parents and leaving the girl fatally wounded. He retaliates by killing his mother and cousins.

For context, this is for a very odd alternate universe I'm thinking of developing where demons are a sentient carnivorous subspecies of humans that are a staple of the world. Essentially, demons are a natural uccurring phenomena that certain individuals are predisposed to become.

 Virtually indistinguishable at birth to humans, demons are thought to be a genetic mutation that develops its phenotypes as an individual ages. They have the same abilities and weaknesses as in canon.

They were, understandably, ostracized from society until a social pact was made that made men and demon alike exist in tandem in one society. Demons would stop hunting humans indiscriminately and, in exchange, humanity would provide regulated, sustainable sources of nourishment.

Tensions remain to contemporary times, but demons now live among humans, predator and prey sharing a fickle equilibrium.