Fanart of AuShinobu and her backstory. Almost the same as the original, except it was humans that killed Kanae. There was a guy who liked Kanae and wanted her as her wife (think like Gaston from Beauty and the Beast), and his two friends would harass Shinobu and Kanae until Kanae finally agreed to marry him. Shinobu studied medicine and types of poison ( she began injecting herself with wisteria without Kanae's knowledge) in her free time. Kanae tells Shinobu she will train to be a slayer, and if she passes, both of them can have a new life in the demon corps, with Kanae becoming a demon slayer and Shinobu continuing her studies. On the way to a demon slayer's house to discuss training, they got stopped by the trio that harassed the sisters. The guy shouts misogynistic remarks at the sisters and calls them crazy for believing a demon exists. As Kanae was leaving, the guy grabbed Kanae's hands to take her with him. A struggle occurred, and Shinobu stepped in to help but was slapped by the other two and kicked at. Kanae managed to break free, which angered the guy, and he pushed her down, making her head hit the wall. Everyone realized what happened, and Shinobu ran to her sister while the trio tried to justify that it was an accident and not their fault. They tried to leave, and Shinobu went to stop them, calling them cowards, but was pushed back by the trio. At the same time, a lower moon came and killed one of the trio. Instead of killing Shinobu, she asks her if she wants to get revenge, and she will grant her that. Shinobu stared at the demon, so many mixed feelings rushing. Her hatred of demons was overturned by her new hatred of humans, and she agreed to get revenge on her sister. The lower moon made Shinobu believe she was helping her, but she was planning to use Shinobu as her personal slave. Shinobu managed to kill the other person running away, but her sister's attacker got away. When Shinobu finally got her revenge (injecting him with poison), she wanted the lower moon to kill her as she didn't want to live. The lower moon wanted to keep Shinobu a little longer and made a deal that she would turn her back to a human if she helped her out for a bit (manipulating her) The lower moon wanted to eventually eat her, but for now, keep her as she was useful capturing victims. She will tell Shinobu she's too weak in demon and human form, so she needs to rely on her. that without her, Shinobu is nothing. In secrecy, perfecting her blood art and injecting herself little by little with wisteria. The lower moon became suspicious of her and decided to end her, but Shinobu got the upper hand. After killing the lower moon and the last of her humanity, Shinobu went through a transformation (like a butterfly) and gained a new form. Shinobu was finally not weak, but she ended up losing the memory of her sister. Shinobu is the only demon to be resistant to wisteria. Muzan finds her useful when he needs to torture a demon with her poison.
The last two slides are bits of info and how my mind is trying to work this Au stuff out. For now, still don't know how to create Muichiro and Sanemi, but hopefully, I will get to it.