In a little bubble in space resides a funny planet that is two worlds in one. The first world is much like our own; white light shines down upon it from a bright sun. However, if one goes high enough above or deep enough below the surface, they will come right back-round into the second world. To our eyes, this world would appear to be lit by an inverted sun where dark is light and light is dark. To confuse matters further, both of these worlds exist in the same place, and they are orbited by one little moon.
Leopiotoid
Floating in the skies of these worlds are the cloud-like treioki. Some are fluffy Arbonimbi while others are silken Dendronefeli. As they grow, their centers become heavy and weak, and with time they will fall away. The younger periphery that ramins will then drift apart. It is an ever-changing environment with many challenges, and breath-taking vistas. A wonderful home for the Leopiotoids.
These fungi people sail vast distances across the open skies; citizens of expansive dominions rich with culture. Aside from just being capable navigators, they excel in their understanding and control of the world around them. The processes of experimentation and manufacturing are treated in a ritualistic manner upheld through tradition. This was particularly relevant when their conquests reached the land below.
Apokrattamata
As the Leopitians' dominions developed into empires, and their governance became bureaucratic, they delegated away their presence in their new acquisitions. However, rather than using local representatives, they engineered new obedient servants, the apokrattomata. The first of these were the Vespidrones in the form of humanoid wasps or bees. Vespidrones primarily upheld the rule of their respective empires among the assimilated peoples of the lands below. The next models were the Emmettons; ant-like people developed to clear land and dig deep into the ground in search of valuable minerals scarce in the sky islands. This is how the Leopitian empires first came upon the other world. Though the mess of history means none now remember from which side they first came. That was long ago though, and the Apokrattamata now live independantly.
Mosiatta and Natsudja
The peoples of the lands below include the mousey, bird-like Natsudja in the light world and the feline, bat-like Mosiatta in the dark world. Their appearance, even within species, can vary greatly, and their cultures even more so.
In one Mosicha kingdom, the people there believe they are the spirits of the those from the other world; come to rest in the afterlife before they are reborn on the other side. Thus, if someone is a peasant on this side with no memory of their “prior life”, it is the result of living an unremarkable or even sinful life in the other world. If instead they are nobility, it must be the reward for having lived a good life. To support this belief, the nobility will claim to remember who they were on the other side and the noble deeds that life produced.
Aside from this, the populace is separated into castes by status and profession. These castes are garbed in distinctive cloaks that gives these people their nickname. The castes also have patron deities known collectively as imps.
However, there are more general deities as well, and they often make up the cast of Cloak folklore. As such, these deities, called conduits, are less associated with specific aspects of the world, and are more about the type of character they play in a story. These tales often revolve around conduits performing some major act deemed either a confluence or a cascade. Confluences are often about joining or entering, while cascades are often about changing or removing.
An example of one of these conduits is Ol' Nob the trickster. O'l Nob, short for Knobildykin Catterwack or The Noble Kin Cataract, is the creator of magic and the head of the Kinnelly Court. The Kinnelly being the fairies of the land. However, the Kinnelly and the magic of Catterwack are not the only mystic thing in the world.
Life and Death
The planet has a kind of substance that comes in two primary forms. The creatures of one world metabolize the substance from one form to the other, and the creatures of the other world do the opposite. For them, this process is synonymous with life itself and thus this substance, in its two forms, is the essence of life and death. When a body is born, it is full of life. When a body dies, it is full of death. When a body is buried that essence seeps through the ground or, if it is burned, it rises through the air till it is sent to the other side.
Arckaryotes
There are some things which arise from merely the confluences of these essences in the right environmental conditions. These are a different kind of magical phenomena known as Arckaryotes. The simplest ones being the gooey, subterranean Plasmecia and the wispy, aerial Miasmecia. Like a terrarium that can move on its own, they contain many microscopic, essence-metabolizing organisms in a self-regulating environment. Interestingly, over many millennia, these beasts can petrify; turning into the gems of the caverns and the stars of the night sky.
There is another example, similar to the Plasmecia and Miasmecia, but deserving of its own name: the Marinecia. Marinecia are rather large and complex. They tend to cycle between an active and dormant form. When dormant, the organism inhabits a lattice structure to form a spore. Under the right conditions, it will become active again and cast the lattice shell aside, but as it is so large, the shell may just end up orbiting the organism.
Lagolopes
Inside the moon resides a species of bunny-like people with horns. As they developed outside the presence of the life/death essence, they do not metabolize it, and since they're neither on one world or the other, they can see the light from both the light and dark suns. This means they see in a depth of color unimaginable to us. If a Lagolope were to land on the planet below, and thus be restricted to the light of only one star, things would look quite dull to them.