This is sort of a take on the definition of "eldritch abomination". It seems out of place, but I'm just treating it like a writing prompt.
Warning: Dark. A realistic view on the "flap of the butterfly's wings".
~o.o.o~
Many things make an Eldritch Abomination. It has to be strange, it has to be unsettling, and it cannot be truly comprehended.
But it is my belief that there is nothing that locks in one's form into any given template.
Things human sized can be just as scary as a 200 story leviathan. Things flesh colored can be just as mind-breaking as ones in colors we cannot truly comprehend.
To be honest... What is an Eldritch Abomination?
In my eyes, it is whatever you don't want anything to be. It, or its full effects, are something that the writer themselves cannot truly comprehend. But above all, it is something that those whom it is inflicted upon cannot accept the existence of. It is so wrong that the victims cannot even perceive it properly.
To put my neck on the chopping block, I am saying that in some cultures some things that are taken for granted can be E.A's for others.
In 1700's if anyone came across the mass of cells known as "HeLa" could be considered this (now defined as an entirely new species). In the 1400's, the self-programming and self-duplicating robot colony created a few years ago would probably qualify too. Both of these examples defy all human logic and understanding of that time. Though now these are considered common and theoretically simple and sound, our sense of understanding has changed that much and grown that much broader/deeper.
Let's go into the future a bit. How about SARS? Or Ebola and Marburg when they first were discovered?
We still only "Believe" we know what caused SARS outbreak. But remember when it first came about? When no lab could confirm whether it was a virus, bacterium, or toxin? SARS effectively disappeared before the final conclusions were drawn. We didn't know what it was or how it worked at first, and could only hope to treat it like a virus or some other sort of known disease. Without knowledge of viruses, or of modern germ theory (post 1800's) Ebola and Marburg seem to be demonic spirits that turn healthy men and women into blobs of ooze (for those who don't know, you are literally liquefied from inside out by time of death/burial). What's more shocking is some of these are airborne and quite hardy...
TVtropes attests that an Eldritch Abomination must be some being that warps reality or some sort of cosmic horror, but promptly contradicts itself later. Let's be honest. Eldritch Abominations are just Wrong. Wrong to the point that even acknowledging something like that may exist scares us.
For times like these, I love Kara no Kyoukai's (from the Nasuverse) "criteria to truly terrify"
1) The "monster" must have an unknown or indefinite form.
2) The "monster" must not have a name.
3) It's no fun if the "monster" can die.
So... let's see if an Eldritch Abomination can be... Small. Let's see if I can take a theoretically probable thing from our world... and show how it could be an Eldritch Abomination for a less... civilized time.
One World for Another: ZnT "orignal flavor"/"Real Life +"
War has gone.
No more armed conflicts engulfed the world, as on another Earth, the United Nations was now the Great Council of Earth. With each country in attendance and all armies reduced and combined into one. The age of conventional warfare was over, gleefully announced to the world as a whole, ushering in an era of "World Peace"
War has changed.
It was now fought with smiling faces and under the table shots, diplomats used only as smokescreens while allies sabotaged each other seemingly for fun.
War had changed.
Attacks were now done by "terrorists", now only highly paid and trained mercenaries backed by any number of countries, coalitions, and parties.
War had evolved.
Technological attacks could shut down vital infrastructure and cripple logistics, often doing more damage than any bombing run could. While armies were reduced in size, the number of defenders only ballooned.
War was evolved.
Once forbidden weapons were finding new use, from the untraceable nuclear poisons, to the repurposed chemical agents dispersed while disguised as gas leaks and industrial accidents, to biological hazards made to seem like a sudden outbreak. All improved and engineered to become nigh-untraceable, leaving countries paranoid and unable to know who to blame.
War was Hell.
Without proof, each member of the Great Council gave the other lip-service, but ordered its own attacks against those who it suspected to be behind things. Conflict and suffering spread and grew, all while the collective leaders expounded the "Triumph of World Peace".
War is Hell.
The attacks were never called such, only noted in the news as "tragedies", "disasters" and "calamities". These catastrophes became prevalent and such losses of life were soon considered the norm.
War is here.
In Japan, Tokyo, to be precise, one such attack, decades and billions in design and funding, was finally being executed.
Here is war.
The backer of the incident scratched its head in conclusion as nothing happened and deduced that the researchers and mercenaries were a sham (becoming more and more common these days), and destroyed the research and accompanying... "materials" so that it could not be traced back to the benefactors.
Hell is war.
Never knowing that the chosen vector, the "Patient Zero", Hiraga Saito, a normal boy kidnapped off of a street, fell into a shimmering portal moments after being released back into the population.
Hell is Here.
~o.o.o~
Day 00, 20XX AD, Akihabara Denki Gai, GCE Quadrant, Earth.
Dazed and confused, Hiragia Saito found himself waking up at a booth in an internet cafe in Akihabara. Unaware he had even fallen asleep, he wondered why he was at such a place. Looking at a clock, he saw that it was hours later than he recalled, and the thing he remembered clearly was walking out of the computer repair shop with his laptop fixed and upgraded. Shaking his head, he quickly grabbed his things and left for home.
He never made it back.
~o.o.o~
Day 7 of the Term, 60XX in the Years of the Founder. Tristain Academy of Magic. Journal of Jean Colbert.
Nothing out of the ordinary happened today, nothing except the young Valliere, of course. She managed to summon a commoner boy dressed in the strangest fashion, even with one of her famous explosions. An odd note is that despite being incapable of normal spells (but not magic as a whole), the summoning was successful and the binding was flawless. Detect magic was cast upon her familiar, but was negative. It He, however had the most particular runes...
~o.o.o~
Excerpt from URJPC historical study log #002, written 65XX:
On what is now known as day TI+03, the first secondary contact from site 001, what is now known as Tristain Magical Academy, is thought to have happened. Due to the nature of this "curse" and the delay from contact with a "pariah" to onset is highly variable, exact time of contact is unable to be pinpointed. At this point in time, the "curse of the zero" was still unknown, and would be first thought of as a Plauge or illness, but the transformative effects it has on its victims and its unnatural pattern of appearance has left many unable to classify it as anything other than a "curse".
As one water-mage once remarked "It is like the effects of a forced flesh transmutation, only done over the whole body and so slowly that blood leaks out of all of the gaps. In the end, the patients are reduced to that black... mass of what's left"
~o.o.o~
Last Journal of Montmorency [...] de Montmorency, Tristain Academy of Magic Student. First Entry. [URJPC Exhibit 003-064A]
"Day 03" [Day TI+27]
The zero, no, the Valliere seems to be on her deathbed, wracked by some sort of illness or plauge that has never been seen before. The word has already spread to the castle and concerns are running high.
It is good news that it is nothing like what we know of the plauge, but the reality of the situation cannot be understated. If this is declared to be a ...
We all know how that would end.
It is because of this, (after much ... deliberation), I have decided to make this journal, enchanted and bound with the Water Spirit's tears to ensure that it and its contents survive ... what ever may come.
This, I hope, will only be a momento of a time I will forget. But if I do not make it, this will be what I leave behind for my family. A last letter of sorts, but longer.
It all started days ago[...]
[Notes: The residents of the Academy believed that the index case was Louise Françoise le Blanc de la Vallière, whose symptoms were revealed by her wounds sustained on a mission under Princess Henrietta of Tristain. We believe that this curse originated from a corrupted summoning ritual or such cast by the young Valliere, and further damaged by her exploits in Albion to become what we know as the Zero Curse today. Unfortunately, an oversight allowed Duke Valliere to collect her body for burial at the estate along with all her belongings, as no other cases had occurred in the time it took the young mage to die, causing the Tristian agents to declare the suspected plauge to be non-contagious prematurely]
~o.o.o~
"Harem Blood Curse" [Day TI+26]
The "Harem Blood Plauge"'s first victim, a young maid recently acquired by Count Mott first began showing symptoms of the "sweating sickness", known as "Influenza" by Romalians of that time. There was no cause for concern at first, but it soon spread throughout the area and claimed many victims, including Count Mott, and 14 of his other possessions, along with Duke Richards, Sirs Elgard, Marquese, and Weirne, and Bishop Romero. The Young Maid "Siesta" survived, but was later executed in fears that she would spread the "plauge".
URJCP notes: Though thought to be another thing at first, this was later reclassified as more cases of the "Zero Curse", as Subject-S was originally employed by the Tristian Academy of Magic. This is the first time sexual contact has been confirmed to transfer the curse (Sirs Elgard, Marquese, Wierne, Bishop Romero, and Duke Richards [...])
~o.o.o~
Day [TI+30]
Records show that a rash of "Influenza" spread throughout the servant's quarters of the Academy. Guiche de Garamont was recalled to his family's estate for 2 weeks for "disciplinary reasons" as cited by records still intact in the Headmaster's Office.
He would be dead 4 days later, much like many of his friends and classmates at the academy.
~o.o.o~
Day [TI+36]
Body of what is believed to be Wardes, traitorous Mage Knight of Tristain, is found in the Main Church in Romalia. Only his face was recognizable, the rest of his body had already deteriorated into black slime interspersed with bone, skin, and organ fragments.
Gallia Closes its borders upon finding out.
~o.o.o~
Day [TI+49]
Princess Henrietta dies mysteriously. Secret records show that she had been "infected".
~o.o.o~
Day [TI+51]
King Joseph of Gallia dies. Nothing else is known. His assistant, a woman by the name of "Sheffield", is the first confirmed case of the curse in Gallia, leading this commission to believe that the King also died from the curse. His body was burned immediately, and his neice Yossette was recovered from a monastery quickly, so no further knowledge is available.
~o.o.o~
Day [TI+56]
The First Eradication order completed. Tristain Academy of Magic destroyed. All infected students, land, and possessions burned.
Further Eradication Orders are completed across Halkegina throughout the weeks.
~o.o.o~
Day [TI+60]
Outbreak claims Germanian Emperor. Albion is thought to have been "infected" at this time, but with all information and knowledge being suppressed by Oliver Cromwell and Reconquista.
~o.o.o~
Day [TI+61]
First publicly announced death due to the "Curse of Destruction" in Albion. Oliver Cromwell dies, and political turmoil spreads.
~o.o.o~
Day [TI+79]
A resurgence of cases in the surrounding areas of what formerly was the Tristain Academy of Magic, along with all contracted fire mages displaying symptoms lead the church to declare it is not a plauge it knows of, and is immune to fire magics. A moratorium on the Eradication Orders is issued, and Water mages who treated sufferers and yet-to-be-executed survivors were interviewed. Later the Church would declare that the deaths were not of plauge, but some sort of curse, probably engineered by Elves, other First-born, or Spirits.
Days later, Pope Vittorio dies, from the "curse"
Notes: [...] since this is before a full audit and tally of deaths from each race, this statement was valid at the time. Even though that once the curse spread to the elven lands, it [...]
~o.o.o~
Excerpt from the Greater States of Halkegina review of the URJPC historical study, 80XX.
What once was called the "Curse of Destruction" or "Curse of the Zero" has been revealed to be a "virus". This "Virus" was most likely summoned [...] inside of a familiar [...]. The number of creatures it can infect is astonishingly large, though bats, mice, and meat-eating animals seem to be infected the most. This "curse" has also singularly stopped the use of familiars over a period of centuries, as it was discovered that while the "curse" may not affect certain creatures, they could still transfer it to their owners and other people.
[...] While being the impetus to bring all of us together, we, the Greater Council of Halkegina, can only hope to believe that we would have come together even without this terrible blight.
~o.o.o~
AN: I'm sorry. I'm not sure if I managed to successfully portray a plague as an "eldritch abomination", and would love to flesh the world and effects out more, but I can't write anymore of this right now. Its.. getting too hard. The screams are getting louder.
~o.o.o~
Improbable real life summon, Saito infected with a Genetically Engineered Ebola/Marburg cross. Airborne capacity and ability to infect birds, bats, and monkeys, with long-delay capability seen in Ebola (can be non-symptomatic and infectious for more than 3 weeks). With none of that no-staying power BS that makes ZEBOV laughable (So that's the Marburg part). (ZEBOV can be summed up as: survive three major days of the assault, you live.)
Yes. Ebola Zaire, with a fatality rate up to 90% is Laughable. It could be FAR worse, given the associated glycoprotiens and mechanism of attack.
For those who may think that my depiction of Viruses surviving an exterminating fire is utter BS, do note that while fire does work (though not as well as it does against bacteria), often it just aerosolizes the virus, so that even if it was not capable of infecting people from the air, it can do so now. This is one of the more prominent theories on how the Spanish Flu was first contracted: by burning infected horse and other animal remains in Kansas.
Heat can kill viruses, but the amount needed is notably higher than the amount to kill most bacterium. Studies have shown that Influenza (Membrane bound and therefore more susceptible to heat) can survive of upwards of 100 C, and the nastier bugs can survive (thankfully rarely) even autoclave temperature, pressure, and times, calling for both chemical and Thermobaric sterilization in high-level labs.