Supernova (Rengoku x Reader)

Chapter 1 - Darkness

A/N: Hello! It's good to see everyone again! How have you all been? For any new readers: GO BACK! This is a sequel to my first book, "My Brightest Flame." Please read that book first before this one otherwise it won't make sense! Thank you for being patient with me. Briefly I will explain this just so we're all in the know: this story no longer follows the original story of demon slayer, this is now my own au of what would have happened with my version of y/n involved. So, please, have fun with me in this creative experiment and enjoy!

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"A supernova is a powerful and luminous explosion of a star. A supernova occurs during the last evolutionary stages of a massive star or when a white dwarf is triggered into runaway nuclear fusion. The original object, called the progenitor, either collapses to a neutron star or black hole, or is completely destroyed to form a diffuse nebula..."

It was dark. Impossible to see. That would be the case if it weren't for the districts that worked together to sustain the area, lit by lights and fire. However, what went past those districts, no one would know. There wasn't a single one of them brave enough to venture too far out. At first, humans would dare to hunt in search of food, only to find most animals were frozen dead. Of course, they couldn't eat that. They fully depended on the demons' quick think to preserve what they had left.

Wrapped in the fur of a wolf, y/n stepped towards her task. Not usually one for fur coats, this was a gift. It had been made into a coat and had been fluffed for extra warmth, the leather on the inside adding more. It was a rare find, as most animals were gone. It had felt worthless and pointless at first to give a demon a coat, as temperatures were never usually a concern for them. Lately however it had been getting colder...And suddenly she was grateful for the jacket. Although she didn't appreciate the person it was from. Entering the capital, she looked to the sky. One of the greatest things about the darkness was that you could see the stars. They always reflected off of the blue gemstones on y/n's necklace. Endless beauty that was sensitive to light pollution. They had never had that problem.

"My medicines will only do so much, humans are very susceptible to the cold. Perhaps the sound district could provide more clothing?" Massive doors gave way for y/n, who had appeared late to a meeting after orders from her boss to check for any surrounding threats. Stray demons were never a problem, but it was a task y/n never minded doing. "More layers would definitely help them." The conversation continued without acknowledgement of y/n's appearance, maintaining its professionalism. However, when she sat, the demon leader of the medical district gave her a nod of welcoming. Y/N returned the gesture.

Every district was led by a demon with a unique ability, their blood demon art. Thankfully, they collectively had the components to sustain life. That was until now. The dropping temperatures had become even more aggressive, and with it, humans would get ill and die. Usually, demons wouldn't care if a human died, but together they had quickly realised that they needed the humans. Their blood was what gave them strength. And so, they had to take care of them.

Shinobu's district handled medicine and healthcare. They would deliver medicine to other districts, each having one hospital with one of her staff in charge. She excelled in her ability to create cures and she would sometimes create poisons just for fun. Y/N almost felt empathy for the humans that lived under her reign, being treated like lab rats when they weren't her next meal.

"Yeah, I could. If I had the materials for it. Animals provide the most warmth for them, so look at Obanai." Snapped the addressed demon, his eyes closed as he sat back. Rarely did Tengen care for these meetings, but now he had no choice. It left him on edge. His district worked in the most confusing ways, they were the reason everyone could hear. He had tried to explain that they had created a barrier system that allowed audio to transfer, but his explanations were lost even on the king. Nonetheless, they were all grateful for the ability to communicate. He also handled clothing, purely by choice. "Well the rest of you don't have any fashion sense, who else is going to make sure that the humans stay flashy?" He cared a lot about looking great and to his credit, everyone looked better for it. He got help from his three human wives, which everyone had considered strange. He couldn't eat them and he could never explain why. They had an effect on his heart and so, they became his wives instead. It was a fast event, as they had felt the same way towards him. It was weird.