A Different Type of Front

Aftermath Mayhem (Demon Slayer)

Hey there! This is part 2 of my Demon Slayer Crossover Arc. It isn't necessarily part of the wider story, but it is a nice side arc. What I'm doing with this is trying to describe the POV of a soldier, in this case an operator named Yuji Asada, and his encounters with demons and demon slayers in the first person.

Date: May 7, 2261
Location: Site T-41, Tokyo, Japan
3 days after Incident Z-JP-TOK

Holy shit what the fuck am I doing with my life. After the mass containment incident, the higher ups and the overseers want some answers. We got the anomalous and R&D departments here now. Especially since that orb. The slayers were allowed to live in the on-site living quarters so we wouldn't lose them in the city somehow. Most of them, when they heard of the Upper moons and Muzan's capture, were extremely joyful, and some even cried tears of joy. Since the demon slayers' only goal was to essentially kill Muzan, they were ecstatic that he was captured. R&D and Biotech classified demons as "Persons or entities which were infected with an extremely dangerous virus." Hold on I'll just get the report again. In more detail, they describe demons as persons who were infected with an extremely dangerous bloodborne virus. The virus itself emanated from Patient M, also known now as "Muzan Kibutsuji". The effects of this virus range from:
Extreme weakness to UV light rays with levels equal to or higher than the sun
Possible development of deformities in their bodies
An unstoppable urge to consume blood or human flesh
Death if human flesh or blood is not consumed
Unlimited Stamina and Endurance (although this may differ depending on the subject's amount of blood consumed)
Growth rate is faster
Immunity to all diseases
Immunity to all poisons (Although this does not include chemicals in gas form)
Enhanced Senses
Wisteria Flowers (demons are extremely repelled by wisteria flowers, and high concentrations of this can kill them)
Immortality (Demons can live forever if they are able to consume a steady supply of blood or flesh)
Increased Speed
Increased Strength
Threatening Aura (Through unknown means, demons naturally emanate a threatening aura, which becomes more terrifying if their power is much stronger. Although robots and AI are not effected. Battle hardened soldiers seem completely impervious.) 
Fast Regeneration (Demons can naturally regenerate even with their heads cut off. If they consume blood frequently this ability may last forever. Solar powered weapons seem to stop their regeneration, and decapitation by "nichirin" works as well. Scientists are attempting to create artificial nichirin for standard use if possible)
Shapeshifting (All Demons all have a shared ability and attribute of shapeshifting through the precise manipulation their body. For weaker Demons, shapeshifting is automatic and usually random. For example, humans that recently became Demons could have horns, sharp nails, fangs or extra limbs that are granted through demonization. Demons that possess more of Muzan's blood would be able to control their own shapeshifting at a more precise level, enabling them to change their appearance at will. )
Supernatural Blood (All Demons have supernatural and special blood that originate entirely from . It is the main source of all the abilities, characteristics, attributes and capabilities, thus being the nexus and most important aspect of Demons. The higher the concentration of Muzan's blood a Demon possesses, the overall stronger they are. Once Demons grow strong enough, they develop supernatural abilities unique to themselves known as "Blood Demon Arts" , powerful paraphysical abilities that can be used through a Demon's blood.)
Curse of Kibutsuji (If a demon mentions anything about Muzan or even his name, they will mutate and perish in a few seconds)

Holy fuck. This shit seems like the stuff you'd see in an anime. Their powers almost seem like vampiric in nature. I bet my whole fucking salary this year that command would try to turn this shit into a super soldier serum. Holy crap. So what's happening now is that we're scrambling to get every piece of information we can on demon weaknesses. We interviewed a lot of slayers today.
-Personal record of Yuji Asada

5 days after Incident Z-JP-TOK

So not much has happened. We ran some tests on the slayers and it seems like they're perfectly normal humans. We brought in psychiatrists to help them deal with the fact that they're fucking 340 years in the future. Turns out the last thing they were doing before they somehow got transported was leading a final assault on Muzan's base or something.

1 week after Incident Z-JP-TOK

So command announced to us what they were doing, but had to make us shut the fuck up about it. What they're basically doing now is trying to integrate the slayers in modern-day Japan. They scrapped the attempt to make synthetic nichirin since it was basically ore that absorbed a shit-ton of sunlight. They decided that solar based weaponry was enough to deal with them. They also told us about "Project Demon". It was essentially trying to make a super soldier serum out of the demon things(I FUCKING KNEW IT!). Basically they were going to remove the weaknesses of the virus. Things such as the weakness to UV light, the need for human blood, the possible development of deformities, weakness to wisteria flowers, and especially the curse of Kibutsuji, and make it less transmissible between people. 

10 days after Incident Z-JP-TOK

So... How should I start? Well command struck a deal with Muzan and the other demons. Essentially, Muzan was to give a steady supply of blood from himself for research purposes. The moons and other demons were to be screened and tested, as long as they didn't kill anyone. Command would give them a steady supply of synthetic human flesh and blood, and the research was to be used to create a cure for Muzan and other demons, but also create the soldier serum that command wanted. Nezuko, a demon who was somehow different from other normal demons, in the case that she did not have a deep urge to consume human flesh, was useful since her blood showed mutations which made it seem possible to create a cure and the serum as well. Her brother, a slayer named Tanjiro was hesitant to allow her to undergo experimentation, but let her since it turns out the only thing they needed was blood.