Humans

The Term "Human" encompasses a vast array of peoples and races, all somehow sharing a similar genetic makeup. The human is characterized by it's uncharacterizable nature. That is to say, a single human could look so completely different from another, you'd never guess they are part of the same species.
For instance, Included in humanity are Merfolk, Changelings, Igneans, Veridians, Avians, Planars, and more. The reason for such variety is that Humans have a strong connection to the land in which they are born, and the magic flowing around and through their mother's womb greatly affects their development.
It is important to distinguish these variations from full subspecies formation. The human genetic code is not altered by it's environment; portions of it are simply repressed or expressed. This means that a human may have an avian father and a changeling mother, but be born a merfolk. Humans are even known to change the expression of their body over several years, if their environment changes drastically enough. This variation of traits and appearances seems to be unique to Valan humans, as travellers from other worlds report each variation as it's own subspecies in their homelands.
Another notable feature of humanity is their powerful innate psionic capabilities. While psionic powers are most common in Planars, they are still much more common in the other classifications than in other species like Elves or Dwarves. These abilities are common yet unexplored enough in most Planar populations to make violent crime levels very low; Any criminal runs the risk of their fellow human tearing them apart in an adrenaline fueled psionic blast. Psionics, while very powerful, are very difficult to control and train, meaning that despite the commonality of talent, psionics users (or psions, as they're called) are about as rare as sorcerors among humans.
Humans can be found in most places on Valus. They commonly live up to eighty years old, though they can get to be around 120.
I will proceed to elaborate on the sub-classifications of humans. Be aware that each human will be vastly different in ability, trait, and appearance from their fellows in their own sub-classification. Each individual is their own.

SUB-CLASSIFICATIONS

Planars

These humans are the most common, and the least specialized variation. These are the people most often thought of when one says "human", so expecting familiarity, I will neglect to describe them in full. Even in this one Classification, they vary wildly in appearance, if not so much in physiology. Their skin ranges from pale to black, their eyes can be blue, green, brown, and anything in between, and their hair can be brown, black, blond, a firey orange, or any combination thereof.
Planars are most often born in open farmland and plains, grassland and deserts, and especially in cities. They are also found in about a fourth of the population of most other subclassifications, proving that some humans aren't as malleable as others. See, Planars seem to be the base form of humans, and the form most often found in travellers from other worlds.
It should be noted that, despite their non-descript nature, most humans of this subclassification have strong psionic aptitude not found in other human variations. It often only comes out when in danger, and when it does, it's effects can be devistating. This means that violent crime is often kept low in their settlements, lest the perpetrator be shredded by an untapped well of psionic ability.
Furthermore, Planar humans also have a lack of limitation in wizardry and sorcery, as their bodies accept all elemental energies in equal measure, while, say, a merfolk might have trouble casting fire magic.

Changelings

These humans are very rare, making up ~0.1% of the human population. They are known by their ability to shift their appearance to match any other humanoid, though they are often unable to copy their traits. For instance, they are unable to fly properly when shifted into an Avian, as their bones are too dense. Their true forms are pale, hairless and largely featureless bodies, with white irises and nondescript faces.
Changelings are usually born to traveling parents, most often merchants. In any environment where a large variety of people are passed and interacted with, a changeling is more likely to be born. Of course, they can be born into any human family.
There is a fair amount of animosity toward changelings among some human populations, especially the insular ones. With most shapeshifters being monsters, many assume changelings to be the same. This combined with a common distrust of someone who can look like anyone, means that changelings can often be found on the outskirts of society. In larger society, there has been a lucky turn of events over the past few decades, that changelings have been more and more accepted. In the major cities, it is not uncommon to see changelings in their true form existing without fear of reproach. I, for one, am glad for the progress.
Some changelings, especially as they age, learn the ability to shift into less humanoid forms. Although they must shift into creatures that are roughly the same size, some have been known to shift into large dogs and the like. These changelings can even restructure their internal body to gain the flight of an Avian, the waterbreathing of a Merfolk, the tough skin of an Ignean, increased strength and speed, etc. However, these extreme shifting processes are said to be very taxing and are not be taken lightly.
Changelings, naturally, have a strong aptitude for transmutation and illusiory magic.

Merfolk

These humans' most striking characteristic is their gills on the sides of their abdomens and necks, giving them the ability to breath in both air and water. They also have webbed feet, and eyes able to adjust to underwater conditions. Their skintone can range from pale to dark, as well as both in bluer shades. Their eyes are usually blue or green, though rarely they may be gold in color.
Most merfolk are born in coastal towns and cities, especially among the dockworkers, fishermen, and sailors. Some of them make their homes and sleep underwater, finding it more comfortable. Some among this population have created entire villages underwater, and rarely come up to the surface. These merfolk always give birth to more merfolk when underwater.
Merfolk that have lived underwater for several generations are almost their own classification. Their hands are webbed, their skin thick and scaly, and some lose their feet and legs entirely to fins. Those without legs are known as "tailed" merfolk. While magic can be used to give them legs, they are usually unable to live on land.
Merfolk have their own kingdoms and societies underwater. However, they can be xenophobic, and considering how hard it can be to reach them without means of breathing underwater, we know little of their political landscapes. They seem to live in city-states along coast lines and reefs, often fighting over territory. They have little care for the ships that pass over their heads, however.
The merfolk you are most likely to see are those who don't actively live in water. They are treated like any other human in most places, even in the smaller, older inland towns. In any given city, you can expect 5-10% of their human population to be merfolk, or up to 25-30% in coastal settlements.
Most merfolk have an aptitude for water and divination magic, and find difficulty with fire and creation/destruction magic.

Igneans

These humans are about one foot taller than the average Planar. They often live underground and/or around volcanic activity. This gives them very thick, hard skin that can resist high temperatures, and eyes that can see well in the dark and reflect light. Their skin is often stone colored, ranging from pale to gray to black. "Redheads" are common among them, though blond and brown hair occur as well. Their eye color has a similar range to their skin, though it can occasionally be tinged red. Igneans create their own vitamine D, and do not require sunlight or special food to survive.
Igneans are most often born underground or near active volcanism. This causes their populations to often clash, or co-mingle, with dwarves and other underground species. Igneans in fact share many traits with dwarves, such as an aptitude for construction and tooling. Igneans are rarely born outside of their kind, as other humans rarely travel to the regions in which an Ignean might be born.
They often live in societies seperate from other humans, and only co-mingle when absolutely necessary. This does not make them unwelcoming, however, as they often have a strong culture of hospitality. The social rules do dictate how long that hospitality should last, so don't overstay your welcome. Their insular nature makes them mysterious to other humans, and many hold distrust towards them. This is compounded by several wars between Igneansand other Humans, generally over food, which can be hard to come by underground. Luckily, there's a lot of trade between Igneans and the common human population these days, largely eliminating conflict. It's the older population that holds grudges against them, but younger folks actively welcome them.
Igneans are known to enjoy traveling and adventure, so while their settlements may be rare and hard to track down, a member of their kind in general is not. There are often a few Ignean families in a given city, though for obvious reasons they don't stay Ignean after a generation or two. For these reasons, it is not uncommon to see an Ignean in any town, city, or road. They are not always welcomed, but many are glad to have them as guards or adventurers due to their sense of justice, bravery, strength, and toughness.
Igneans have a very strong aptitude for fire magic, so strong in fact, that many are said to be able to breath fire at birth. They're also very talented at creation and destruction magic, as well as the creation of enchantments. They struggle with more precise, sophisticated magic like scrying.

Veridians

These humans are approximately 1 foot shorter than the average Planar Human, but are much leaner and stronger. They are covered in a thin layer of coarse fur, excluding the palms of their hands and the soles of their feet (The prominent human head hair remains the same). Their skin color and hair color trend darker, especially in colder climates. They also have a strong prehensile tail, useful for navigating treetops and dense brush. Their face has a slight muzzle and pointed ears, giving them a cat-like appearance. Their nails on their fingers and toes are pointed and sharp.
Veridians are born in dense forests, anything from taigas to rainforests. This may influence their appearance, but they're all Veridians. Veridians are only very rarely born to non-Veridians. Tragically, this means that Veridian infants are often abandoned if born to these other human forms. This fear and rejection is waning in modern times, as Veridians are being accepted into our society more and more.
Veridian societies are known to exist in most densely forested areas. They are largely nomadic, though they are known to farm the fruit trees and bushes that they return to regularly. Regular contact with the outside world through trade means that their language remains largely of the Common tongue. Their diet consists mostly of fruits, nuts, and roots that they are able to farm and forage. Veridians spend most of their time making and playing instruments, constructing traps for animals and hapless travellers, and cutting down said travellers while laughing loundly (I, unfortunately, speak from experience). They neglect most clothing except to cover their loins, as their fur is generally good enough covering anyway.
Veridians are rarely seen living in cities, though it isn't unheard of. It is difficult on their minds and bodies to adjust to such a place, so most Veridians who live in cities are born to families that had already lived there. These Veridians have their traits softened somewhat by their time spent in a city, especially if spent during their formative years.
Veridians have a talent for restorative and nature magic, though the extent of this in their societies are simple words and touches of healing.

Avians

These humans are about one and a half feet shorter than the average planar. They have porous bones, making them very light. They are covered in a coat of feathers in most places on their body, and have flight feathers running along the length of their arms, giving them the ability to fly. Flying straight up can be tiring for them, so they tend to use high places and updrafts to gain altitude. On the locations of their feathers, it can range from just their arms, to their whole bodies, depending on the individual. These feathers do replace their hair, and can be just about any color you can find on a bird. Green eyes are especially common among Avians.
Avains are most often born high up on mountains or airships. On any given mountain, you can expect to find an Avian community about fifty percent of the time. Unfortunately, many Avians are intentionally born to Planar parents as a sign of status. To this day, there are contests and showings of Avian models. While this isn't in itself a bad thing, the birth of Avians for specifically this purpose is... Distasteful. Even still, it remains popular among the ruling class, though none of these Avians ever actually end up in the ruling class.
Avian societies are loosely collected communities that share resources and knowledge, meeting on mountaintops and plateaus. They love to travel, and individuals often fly between these communities freely. Avians are well known as adventurers, and often incredible archers at that. It is notable, however, that they are not very strong, and it doesn't take much to hurt them if you can reach them. When not adventuring, they spend their time telling stories and jokes among their kind, playing jokes on travellers from above (I also speak from experience here), and trading for goods. Their diet consists of poultry and food they're able to forage and trade for. They don't farm, but they're able to trade food for their feathers (highly valuable) and news. They say news is always a wing's flap away with an Avian's connections.
Avains are somewhat common in cities and towns, but they rarely stay for long. They're more comfortable on the open road, or in their case, the endless skies.
Avains have an aptitude for wind and gravity magic. When training them, they often find they've already been using a small amount of sorcery to suppliment their flight.

Condians

These humans have nearly the same physiology as Planars, except adapted to the cold. Most of them have a layer of white fur covering their bodies, and dark brown eyes. They're often introverted and cold, though not heartless. All other traits seem to be identical to Planars. Condians are the most recently discovered human variant.
Condians have only been found in the Condian Empire and surrounding regions, as they are the only regions cold enough to produce such children. Indeed, southern colonizers of the Condian's land have reported having Condian children. This makes it important to distinguish between native Condians and Condians on the whole.
Information on the native culture of the Condians can be found Here.
Condians are very rare among the general populace, prefering to stay in their empire if native or in the northern colonies if not.
Condians have an aptitude for frost and time magic. Condian sorcerers have been known to end battles instantly with a selective time stop spell.

History

The origins of humanity are shrowded in myth and legend, but we know from ancient Dwarven census that humans were among them as early as 10,000 years ago. During this time, they seem to have been a minority among the Great Dwarven Empire, and existed this way for many thousands of years. While these Dwarves did not seem to look down on humans, they also tried to stay seperate from them. Human-Dwarve marrage was taboo, and humans were not allowed to take positions of power in the empire. It would seem the Dwarves wanted to maintain their racial identity and culture rather than blending with the new Human population. Despite this discrimination, little prejudice remains between the two species today.
As far as is known, humans stayed this way until the Great Dwarven Plague, which massively depleated the Dwarven population and forced those remaining to sequester in the mountains, fighting for what little they had left against a swarm of monsters beneath the Ahmia mountain range. This left Humans to take charge across the lands of Fortith and Ichraya. From here, Humans spread themselves across the world, forming city states and eventually nations. In many places, the new human government was based on the old Dwarven governments. Some theorize that, as they died or emigrated, the Dwarves included humans in their government more and more, as a necessity due to the human population becoming a majority.
Now, after a few more thousand years, humans are the most populous species on the planet, and control most of it's territory. They have no real racial loyalty, however, and often fight amongst each other. This is good, as if the human population were to unite against the other races, it would likely lead to the most terrible war this world has ever seen.