Elves

Elves represent the eventual success of the Xylian program for creation of a Dominion's servant caste, create by a combination of extreme genetic modifications, hereditary mentalsculpting, eugenics and perhaps a few more things that even the Second Era Empire didn't know about.
The process was an astounding success, enough for the resulting species receive a name from a xylian word for 'servant' and de facto becoming the xylian definition of the word for the rest of the existence of the Xylian Dominion.
Majority of the elven subspecies were too specialized, however. It was done intentionally by the Xylians, as one of many safeguards supposed to prevent them from rebelling against the Dominion. However, when the Dominion perished in the Black Iron War, the entire system broke. Numerous subspecies died out in the following chaos, others were reduced to a small remnant tethering on the edge of extinction.
This opened a way for a long period of wars that have eventually resulted in majority of the elven countries in Karadia collapsing, and humans becoming a - narrowly - dominant species in the continent.
Today, elves have mostly given up when it comes to attempts to remedy that, and has to a varied degree assimilated with the general population. While there are still elven vassal countries (in number only narrowly inferior to human ones), their citizens consider themselves to be citizens of the Grand Empire, with a few rare exceptions.

Basic Information

Anatomy

Ancestors of elves were humans living on the steppes and mountains to the east of Karadia before they were caught, bred and purposefully geneengineered by Xylian genmaturgists. While their general appearance seems the same, Xyls modified them quite significantly.
The biggest change in their stature is that all elves seems to lean strongly towards slimness. It's very hard for one of them to have a body-builder's look, as their muscles work (and grow) a bit differently, in a way best described as growing 'inwardly' rather than outwardly, probably with some magic involved.
Strongest elf alive will still look like random, not very strong human (while being able to bend said human like a pretzel), a common cause of human defeats in battles against the elves. They will also rarely be taller than 1,7m, with 1,6-1,7m being the standard height (for both elven males and females).
This also includes secondary sexual characteristics - only one or two subspecies have bigger than 0% chance of growing large (by human standards) breasts or asses, the rest remaining uniformly on the slender side. In case of the breasts, this translates to C-cup sizes being the dominant majority, with rare D-Cups and absolutely no cases of anything bigger than that.

Biological Traits

Iron Allergy

All elves are allergic to iron and all alloys that include it. This condition is believed to be caused by Xyls on purpose, to render their servants biologically incapable of touching and using the xylian warmachines and their own, personal, techmaturgic weaponry.
This trait varies in intensity between the subspecies. High elves, for example, are a sole exception that lacks it entirely. On the other hand, the heavily magical (and experimental) subspecies like ice elves have the iron allergy especially enflamed, enough to suffer a guaranteed anaphylactic shock after being grazed with an iron dagger, which serves as their greatest weakness.
The standard reaction of the elves tends to be a widespread rash, with some nasty dermatological issues if one decides to remain in contact with iron for an extended period of time. To avoid them dropping dead due to iron in their own blood, the elven bloods replaces it almost entirely with copper. The result is a colourless blood that turns blue when oxydized and uses haemocyanin instead of haemoglobin to carry oxygen around.
The cultural, military and economic results of the iron allergy is the post-Xylian elven cultures turning their attention to other materials, from bronze to certain very magical forms of wood. The Second Empire's plans to free the elves of the allergy through genetic manipulation were unfortunately scrapped when the Twilight War happened.

Subspecies

Originally, there were fourty subspecies of elves. Many of them, however, went extinct - some of them were wiped out by their creators after being declared useless, others were killed by crossbreeding in the chaos caused by the many invasions and wars of the Pre-Imperial Era. The imperial scholars has divided them all into four categories.
Primary Subspecies are those that were created by Xylian Dominion to serve as a basic inhabitants of a significant parts of the Dominion's territory. They are the most common subspecies of elves due to how widespread they were before the fall of the Dominion. Most of them created major member-states of the Confederation of 40 Tribes, with some of them remaining
Secondary Subspecies were created to serve a particular role in the Dominion's society. Examples include an entire species designed to serve as elite combatants for the Xylian army, to explore the Labyrinth or to act as foresters and hunters. Due to often being spread in the territory of a Primary Subspecies, most of the extinct elven subspecies were Secondary ones.
Tertiary Subspecies were created with using certain type of magic in mind. They were the rarest, and often the most unique subspecies. Their uniqueness often serves as protection against dying out - many of them simply can't crossbreed with anything else, and they are all a very useful asset to any country, resulting in those subspecies often installing themselves as a ruling caste for the societies of other elves.
Quaternary Subspecies were created after the fall of Xylian Dominion (and thus aren't counted to the original number of forty subspecies, unless they used to be one of them after receiving a significant revamp). They are rather few and most of them were created by various gods and deities. Due to that they tend to be rather different from normal elves.

Subspecies List

Amber Elves, a Quaternary Subspecies created by some of the wild elves after successfully rebeling against the Wild Courts. They are de facto the elven equivalent of the halfdaemons, born from the merger of the elven blood with that of the fae of the Courts.
They appear 'more' elven than other elves - they live significantly longer, with the strongest of them being functionally immortal, and they possess significant natural talent for magic. Unfortunately, most of them serve the Amber Crown, from which their name hails and which makes them an enemy of the Grand Empire.
Ashen Elves, a Secondary Subspecies created as a variant of Mountain Elves. They were made to inhabit places surrounding active volcanoes and were tailored to thrive in such a hard environment. After the Black Iron War they mostly degenerated into primitive barbarians, often worshipping various volcanic-themed gods of destruction (that needs to be appeased with various sacrifices). They are on the verge of dying out, and continue to exist mostly through the help of the Grand Empire.
Blood Elves, a Secondary Subspecies created to serve as elite bodyguards of Xylian sorcerers and their magical aides. Counted into the dedicated warrior subspecies, and thus both omnivorous and lacking the allergy to iron.
They thrived during the age of Dominion, during its late stage growing in numbers to the point of creating whole armies. They almost died out during the age of the post-Dominion elven countries, today being on verge of extinction. Maintained only through the imperial effort.
Boreal Elves, a Secondary Subspecies created as a variant of Forest Elves. They were made to inhabit - and act as foresters slash hunters for the Dominion - in the north-eastern parts of its territories, among the vast (and often cold) forests on the western verge of Dragonbone Mountains.
While they suffered a significant level of damage during the human invasions, they were saved by their remoteness - there were better places to settle in. Today their entire population lives in the Visenian Commonwealth. So similar that many scholars classify them as a race of the forest elf subspecies.
Dark Elves, a Secondary Subspecies created to serve as a mean for the exploration of the Labyrinth. They also underwent a vastly different system of eugenics and selective breeding for reasons unknown, that always made them feel different from the other elves.
Due to a combination of unexpected factors (and perhaps some divine meddling) they were catapulted into becoming one of the most numerous elven subspecies in modern times.
Desert Elves, a Primary Subspecies created to serve as basis for elven population in the south and southeast parts of the Dominion. They are especially well adapted to living on deserts, where they remain a very populous subspecies. Other than that, they are mostly unremarkable, and with many of them living as pretty much desert tribes they lack significant political importance in the empire. Many of them live within the Rehalian Union territories.
Domestic Elves, a Secondary Subspecies created to serve as house servants of the Xyls themselves (and few very succesful elves). They were essentially a subspecies of maids, butlers and housekeepers.
Widespread and known for their extreme beauty, they were among the first elven subspecies to die out due to crossbreeding. It was naturally forbidden, but domestic elves were de facto slaves - and a very beautiful ones. There could be only one result to that.
Fire Elves, a Tertiary Subspecies created as dedicated fire magicians of the Xylian Dominion. Often considered an elven variant of Halfdaemons. Used to serve as a religious caste of elves in the southeastern parts of the former Dominion (at least before the rehalianism spread there).
Today most of them lives in the Kasytian Empire, whose fire worshipping culture made it a very popular destination for the fire elves from places overtaken by the Rehalian Union that seeked to find a better place to live in.
Forest Elves, a Secondary Subspecies created to serve as foresters, hunters and messengers. Their stamina is extraordinary - they can run for days and sprint for hours, while also developing into excellent archers thanks to their great eyesight.
They have, however, suffered grievous casualties during the Forest Wars against the Wild Courts, that has costed them the majority of their population that has either died, became wild elves in the service of the Courts, or did that but later rebelled and became the amber elves serving the Amber Crown.
Today the true forest elves are a relatively rare sight, although their population seems to be steadily regrowing at least in Elvhara.
High Elves, a Secondary Subspecies created to become an elite military force of the Dominion. They are both perfectly omnivorous and lack the allergy to iron. They are also living engines of destruction, with every single high elf being a natural One Man/Elf Army, capable of slaying dozens of human and beastkin warriors of similar amount of experience and training.
Their reflexes, strength, agility and speed are all off the charts, and so is their natural magic talent. However after suffering terrible casualties during the Black Iron War, numerous pre-imperial wars and the Twilight War their population exists on the verge of being able to sustain themselves, and it's heavily suspected by many that it's actually beneath it, with the high elves more and more commonly forced into inbreding just to continue existing.
Ice Elves, a Tertiary Subspecies created to master ice magic. At some point after the fall of the Dominion, the entire species fell into the shadow of the Nythrathril, better known as the Ancient of Frost.
Today they are all considered to be irreversibly corrupted anda willing servants of the Umbral Bond. As a result, they are considered to be a kill-on-sight target within the Grand Empire. They also serve as the priesthood caste of the Ice Kingdoms.
Iron Elves, a Secondary Subspecies that was created with metalworking in mind. As one can expect from that, they are the second exception to the iron allergy among the elves. They are tough, strong and have a special ability allowing them to analyze a metal object on touch, with the iron elf immediately knowing its internal structure and composition.
The Xylians have only settled them in the Iron Mountains, where they established a thriving community alongside the Stone Elves. However, they were also settled under Vestiria and Alvaena during the times of the Confederation of 40 Tribes.
Machine Elves, a Tertiary Subspecies made to serve as dedicated techmaturgists and engineers. It is unknown why they were limited only to a very limited area in the Dominion, and why they decided to hide themselves from the other elves, pretending to have gotten extinct alongside the Dominion and never becoming a part of the Confederation of 40 Tribes.
This helped them go completely extinct centuries after the Black Iron War in its repetition, when the mysterious masters of the Clockwork Isles decided to thoroughly annihilate their fledgling empire. The reason for that has remained unknown.
Moon Elves, a Tertiary/Quaternary Subspecies made to be naturaly capable of potent dark magic (while also being nocturnal and possessing a natural nightvision). They served as priesthood/mage caste of a significant part of the western Karadia before the devastating war against the sun elves, that they lost.
The remnants were picked centuries later by Luna, and were altered to suit her needs. Today the moon elves are almost entirely loyal servants of the Shadowlight Covenant, though precious few picks different lifestyle which is enough for the Grand Empire to not consider them irreversibly corrupted.
Mountain Elves, a Primary Subspecies created to serve as basis for the elven population in mountainous regions. They adapted to that environment well enough to mostly resist all the invasions of the elven era, but due to unknown reasons they have mostly fell into barbarism.
The most grounded theory attributes it to the mountains being a natural source of isolationism, with the collapse of the mountain elven country usually leading to dozens of communities separated by mountains, most of which eventually declined further into different tribes.
Today, the 'civilized' mountain elves are very rare. Majority of their species serves either the Nine Hordes or the Dragon Claw, remaining a perpetual nuisance to the Grand Empire and its population.
Night Elves, a Secondary/Quaternary Subspecies, created by the Xylians to serve as a biological caste of prostitutes, courtesans and living rewards for the most loyal and successful of their servants. They almost died out after the fall of the Dominion due to the no longer restricted crossbreeding and lack of other useful skills (sex can only take you so far in the age of permanent wars).
Their remnants were 'saved' by Procacitas of the Rapturous Ecstasy and became her servants, although occasionally some of them get tired of this type of lifestyle and choose to live differently.
Sea Elves, a Primary Subspecies created to inhabit areas on the coasts of the seas and on islands. Served also as mariners of the Dominion. Today they remain one of the more populous subspecies of the elves, even if they coastline countries were mostly crushed in the past.
They maintain many island countries, including the (Despotate of Elevhia that remains a rare case of an elven country that remains completely independent. This contributes to their reputation of being equally gifted as fishermen and merchants as they are as slaves and pirates, mostly due to Elevhians unsavory reputation.
Shadow Elves, a Secondary Subspecies that is classified by some as Forest Elves' races due to playing almost identical role and having almost identical improvements and special skills.
They only inhabit a single region (Kingdom of Armarivia, which was alternatively the vassal state of the Nikopolan Hegemony and the Vhessan Empire for almost the entirety of their history) and has, as a species, seceded from the Grand Empire together with its current overlords.
Snow Elves, a Primary Subspecies designed to serve as population basis in the northern lands of Karadia and as border guard against various strange things living beyond them. They were crushed by humans during their invasion and were driven further north, essentially becoming one of said strange things beyond the civilized lands (with some help from the Nythrathril).
There are uncorrupted communities left in both the Visenian Commonwealth, the Grand Empire of Karadia and the Kingdom of Drakha, but they are far outnumbered by those that has irreversibly become part of the Umbral Bond.
Steppe Elves a Primary Subspecies created to serve as a population basis on the steppes of the eastern Karadia. Great riders, that has essentially lost their steppes when the Twilight War shattered the Empire.
Today they seem to be slowly vanishing from the Grand Empire of Karadia, often moving to less shattered (and more open) eastern Commonwealth. However the sheer number of them means that this process with take millenia to end.
Stone Elves, a Secondary Subspecies that was created with mining and stoneworking in mind. They are tough, strong and have a special ability allowing them to 'feel' the structure of stone on touch, slightly similar to a sonar.
The Xylians have only settled them in the Iron Mountains, where they established a thriving community alongside the Iron Elves. However, they were also settled under Vestiria and Alvaena during the times of the Confederation of 40 Tribes.
Sun Elves, a Tertiary Subspecies created with light-based magic in mind. It ended up installing themselves as priesthood/mage caste of the half of the western Karadia, only to mostly lose that in the aftermath of a truly nasty war against their hated enemies, the moon elves. They won it, but the casualties they suffered made their influence wane.
Today they still exist and remain fairly influential, but mostly as closed communities of really dangerous servants of Sol.
Swamp Elves, a Secondary Subspecies created to inhabit (and fight in) the swamps, but this rather limiting biome has kept them at the very fringe of the Dominion's society. Without it, they have entirely given in to barbarism, but has survived the resulting wars mostly by inhabitings lands that nobody else wanted.
Today they are entirely gone from the Empire, but still maintain decent numbers in the Visenian Commonwealth.
White Elves, a Primary Subspecies created to serve as the backbone of the Dominion's elven population in the west. They are noticeably unnoticeable, with lack of significant adaptabilities and abilities, save for their numbers and wide spread (that has allowed them to survive the brutal pummeling they received during the fall of the elven empire).
Today they are mostly unremarkable, and among the groups that best adapted to living in the Empire.
Wild Elves, a Quaternary Subspecies created by the Wild Courts in the aftermath of the Forest Wars, mostly by altering their forest (and sometimes white) elven captives.
The Wild Elves are the primary mortal members of the Courts, and have evolved into a culture that can only be described as otherworldly. Many of them have rebelled (and become the amber elves) at some point, but ever since then the attempts to not serve the Courts has become incredibly rare.

Genetics and Reproduction

Elven reproductive system underwent serious modifications at the hand of Xyls. It is believed that there was a central elven species for a while, created directly from the captive humans. Then it served as a basis for creation of elven subspecies. It was, however, a rather flawed idea.

Crossbreeding

Elves are, in fact, cursed by the very concept of crossbreeding. They are limited in procreation to other xylmades, some heavily magical species (like shapeshifters and high dragons) and spirits.
The real problem, however, is that when elf of one subspecies has a child with an elf of another subspecies (or any other xylmade), the result will be sterile and with an extreme high chance of suffering from birth defects and genetic disorders. This essentially allows the elves to have children only with the species whose reproduction has more to do with magic than with biology - or others of the same subspecies as they are.
This wasn't a problem in the Xylian era, due to their extreme approach to all mixbloods (they exterminated them, sometimes after some experiments to see if there wasn't a beneficial mutation in their genes). When the Dominion fell, the result of this mechanism was a self-segregation of many elven subspecies, which in turn only heightened the problems caused by the collapse of the Dominion's internal cogwork of interdependencies.
The threat of giving birth to a mixblooded elf (sometimes called with the derogatory term of 'low elves') makes most elven societies rather xenophobic, although - interestingly - only to other xylmades. Humans - with whom the elves simply cannot have children - are treated with much less dislike.

Pregnancy and Fertility

Elves remain fertile for much longer than humans. In fact, most females remains fertile until the death of old age. On the other hand getting pregnant while very old (especially after their hair goes white) is very risky to both children and mothers.
On the other hand, their periods are painless and bloodless (a feature that has probably inspired the creators of the high humans, and the chances of miscarriages and birth defects are greatly reduced when compared to humans.
Very important thing for elves is that while they can have sex all year long, they can have children only for two months a year, surrounding the summer solstice. It's believed that Xyls hoped to have better control over their reproduction as a part of their long-term eugenics program.
With around nine-ten months long pregnancy, this means that the elves generally give birth a month or two before the fertile period, which is a necessary cooldown period to be able to safely get pregnant again.

Growth Rate & Stages

Elves achieve adulthood quite normally (they stop growing about their twentieth birthday), but get older much different than humans. Their face never gets wrinkled, their skin remaining the same until their death of old age (which occurs after about one century, of course if they avoid dying from unnatural causes). Their hair does get white, but it happens much later and much faster. In most cases merely few years prior to their death, making it a good warning sign.

Dietary Needs and Habits

Elves lack fangs and have digestive tracks that operate a bit different than the ones of humans. This makes them generally more suited towards vegetarian diet. However, they're not restricted to it.
They do not require meat in their diet, being easily able to gather all the nutrients and microelements from a purely vegetarian diet, but can eat it purely for the taste. They have a marked preference for softer meat, and usually find it more palatable as a part of a soup. Fishes are much more welcome and much less problematic.
They have a major problem with alcohol. They are extremely resistant to it, and making them drunk is extremely hard unless one uses a lot of very strong alcohol. The problem with that is that it happens due to their altered biology showing effects of inebriation differently than it happens in humans rather than being more resistant to it in a more conventional way.
In short, elves will often drink themselves to death before showing signs of inebriation. This is believed by many to be a Xylian way for discouraging alcoholism among their workforce in order to maintain productivity, however one that simply didn't work as elves managed to find an alternative to alcohol in the form of different drugs. Usually hallucinogenic or sedative plants processed into herbal teas or smoked.

Additional Information

Facial characteristics

They are different than humans in a way of an almost complete lack of facial hair. They lack both beard and moustache, with only eyebrows being there. The rest of their faces are usually identical to humans. The other notable difference is their uniformly pointy ears.

Subspecies

Primary Subspecies

Desert Elves
Mountain Elves
Sea Elves
Snow Elves
Steppe Elves
White Elves

Secondary Subspecies

Ashen Elves
Blood Elves
Boreal Elves
Dark Elves
Domestic Elves
Forest Elves
High Elves
Iron Elves
Shadow Elves
Stone Elves
Swamp Elves

Tertiary Subspecies

Fire Elves
Ice Elves
Machine Elves
Sun Elves

Quaternary Subspecies

Amber Elves
Moon Elves
Night Elves
Wild Elves