This is an example cosmology you may use for a rough idea of how the universe of your setting using these rules could work. This is only a suggestion so any group can use their own versions of a cosmology adapting as much or as little of what is presented here as possible.
The cosmology can be broken into three parts, the World which is where your games will normally take place. The Realms which are the domains of supernatural entities that border the World but still lie within the bounds and laws of creation. Then there is the Outside which lies outside of creation and whose denizens and nature defy the standard laws and rules of reality.
Realms are often broken down into Domains, which is an area ruled over by a Master who controls a Domain’s environment, what kinds of people, fauna, and flora may be found there, and in some cases what the rules of reality for the Domain are.
This is where your setting takes place. The cultures, peoples, history, and more are entirely up to you. This largely should be customised to the Table and their adventures.
A commonality is each world during the process of its creation a World Soul was nurtured, from its existence does life grow upon the world. It is a World Soul that fuels the primordial magics of World Speakers and Rangers. The nature and appearance of each Soul is unique to that setting. Likewise feel free to play with how it bestows its power to mortals and just how it gives life to the world.
If you desire, there can be other worlds each with their own World Soul. You may be able to access them via travelling through the shared Realms that neighbour the World or maybe they can be accessed via space travel. The other Realms that connect to one world are usually connected to other worlds as well. But feel free to play with this concept. Maybe a world has isolated Realms that connect to no other world, or maybe a world is not connected to a specific Realm, what effects could these situations have? Feel free to play with these ideas for fun adventures for the party.
The World and all other worlds and the space between them are located on a shared space called the Material Realm. This aspect can largely be ignored unless you want multiple worlds to exist, treating mentions of the Material Realm as the World.
The Realms are the domains of supernatural entities that reside within creation. The exact nature of each Realm and their denizens you should feel free to customise appropriate to your setting, as well as how to travel between them and the World. Is it via portals, spells, or other rituals?
The Realm of Dreams borders the Material Realm and is entirely dependent on the denizens of the Worlds that make it up to form both form and substance. For each world in the Material Realms there is a separate Realm of Dreams. It is believed the realm was created from the dreams of the World Soul and that as life flourished on the World so did life spring into the Realm of Dreams born from the dreams of mortals and their emotions.
Every entity who lives in the World as they dream creates a firmer and firmer minor Domain for themselves, the entities that live their given life via the Dreamer that created it. If the Dreamer dreams of a few individuals, creatures, or places again and again then that becomes a more permanent fixture of the Domain, with individuals gaining more free will as they dreamt of more and more. When the Dreamer passes away the Domain will begin to crumble and its protection against the wandering forces of the Nightmare will wane, allowing them to attack the denizens, with only those with sufficient free will able to flee and find safety in the Realms of the Fey or in the Dream Domains of another. Though some of the Dreamt have sufficient power to be able to become the Master of the Domain giving it the same protections as those offered by a Dreamer against the Nightmare.
Some entities are born outside of the Dream Domains, often born over time of the strong emotions, feelings, or concepts of the mortal folk of the World. These will become spirits who act on their specific emotions or feelings that lead to their birth. Some say it was these spirits that taught the first Battle Channelers how to harness their emotions in battle. These entities will vary in power but can, like Nightmares enter a Dreamer’s Domain and through the Dreamer's dreams influence the mortal World. Some of these spirits may, if powerful enough, even create their own Dream Domains. These Domains are the closest things the Realm has to nation states, and each may have their own civilisation. They are popular places for Dreamwalkers, mortals with the power to consciously leave their Dream Domains to visit to wander the Realm, to visit and parley. It is also these Domains that stand as the bulwark against the constant forces of the Nightmare, the prevent domains falling and allowing the Realms of Nightmare to expand.
The Fae are not natural to the Realm of Dreams. No one knows where they come from, bar the eldest members of the Courts. But what is known is they decided to assist with the Nightmare early in the history of the Realm of Dreams and decided to settle forging their own Dream Domains.
The oldest of the Realm’s spirits know that this was not wanted assistance nor was their settlement of the Realm welcome. But with the denizens of the Realm having to constantly fight against the forces of Nightmare, they are in no position to oppose the Fae.
The Fae are split into three Courts. The Seelie Court, otherwise known as the Summer Fae. The Unseelie Court otherwise known as the Winter Fae. And the Court of Change otherwise known as the Auroral Fae. Each Court is a set of interconnected Dream Domains, each one with an Archfae as its Master. The Domains tend to be traded between the Courts in their games of politics between the Courts and different Archfae.
Some have come to speculate that potentially the Fae are a specific kind of Outsider that came to creation, but have been altered or changed in the process, to partially follow the rules and laws of creation. How or why is unknown. But it would explain why some Fae can perform actions reality would not normally allow.
The Realms of Nightmare are born of the darker emotions of the mortal races of the World. Like a sickness they spread into a few Dream Domains overtaking them and destroying the denizens who lived there and slaying the Dreamer who made the Domains. From there the Nightmare spread, with each Dream Domain that falls the Realms of Nightmare grow across the Realm of Dreams allowing more Nightmares to be spawned.
Individual Nightmares usually cannot enter the Dream Domain of a Dreamer or another powerful Master, but sometimes an especially powerful Nightmare may be able to break through though much weakened by the effort. This is why some mortals may have the odd nightmare as not long after the Dreamer awakens the denizens of the Domain will have slain the Nightmare. However, while a Nightmare is within the Domain its wards will be weakened allowing others to enter. This means any breaches in a Domain's defences must be dealt with immediately lest another Domain become part of the Realms of Nightmare.
The Realms of Nightmare due to it being a wellspring of negative emotions including fear has led to the barriers between it and the Realms of Death becoming extraordinarily thin. This has led to the denizens of Death also having to stave off attacks by the forces of Nightmare.
The Astral Sea is the space between the different Realms of Dream, this can only be entered as souls separated by their bodies and tied by a single thread to guide the wanderer's soul back to their material home. It is also said there are hidden portals within this sea that connect to the Realms of the Heavens and the Realms of the Masquerade.
The Realms of Death are where mortal Souls go after they die. There are a variety of different individual Realms that make up the entire Realms of Death. Some of these are connected to specific Domains of the Realms of the Heavens as afterlives for the followers of specific Deities and other Eternals. Some other Domains are formed around the beliefs of different cultures or folk as to what happens to them after death.
The Realms of Death has a number of locations where the barrier between it and the World, usually referred to as the Veil in this case, is thin. Allowing spirits of the deceased to cross back over, but also allowing necromancers and others who can channel and interact with spirits to perform their magic with greater ease.
The Realms of Death also border and have entryways to the Realm of Dreams, specifically the Realms of Nightmare. This has led to many spirits of those who practised combat when alive being called from multiple Realms to answer the call and protect the dead from the forces of Nightmare.
Within each individual Realm it may be further broken up into Domains of Death, these are led by Masters who are especially powerful dead known as Deathlords, though these tend to be found on Realms not watched over by other powers.
The Ethereal Realm is a Realm primarily considered part of the Realms of Death that connects between the Material Realm, the Realms of Death, and the Realms Primordial. It is this Realm that allows souls of the deceased to move to their afterlives. It is a realm shrouded in the thickest mists.
With areas closer to the borders of other Realms (the Border Ethereal) which have areas matching a location in the Realms they overlap. The deeper areas away from other Realms (the Deep Ethereal) is entirely uncharted and none have been able to pierce the thick mists.
The Realms of the Heavens are where deities and other Eternals may be found. There are a variety of different individual Realms. Some only as large as a single Domain with the Eternal as its Master. Some Realms are made of interconnected Domains, these tend to be dedicated to a specific Pantheon or other conglomeration of individual Eternals.
Some of these Domains are connected to specific Realms of the Dead as afterlives for the followers of specific Deities and other Eternals.
The Realms of the Heavens are probably the most detached of the Realms from the World with little to no connection between them to be able to be crossed over. Though it is said you could follow the path left by the faith of an Eternal’s followers to be able to lead you to the Realms of the Heavens, though none had been recorded as successfully trying such a feat.
The Realms of the Masquerade are many and bound in endless conflict between the Masters of each Realms constituent Domains as well as those who claim leadership over these Masters in wars against the other Realms of the Masquerade.
The history of these Realms lies in the history of one of the Eldest Eternals; it is said they created thirteen servants, each born to be an embodiment of evil, their servitude to the Eternal marked in their mask. Each mask was unique to each member of the thirteen. The Eternal wished for an army however and so cut down each of the Thirteen, as each was cut in half their masks shattered likewise, the two halves each reforming into a new entity. One half contained all the bestial destructive power of the primogenitor these became known as the Archabyssals and the other gained their intelligence and scheming nature instead who became known as the Archmalevolents. As they reformed and bled so did the thirteen lineages of the Masquerade was born, each one of the Masked Evils bearing the mask of their primogenitor either showing the half of their bestial side or the half of their cunning side.
When one of the Masked Evils dies, they like their primogenitor are split in half producing two opposites one abyssal, one malevolent both with half of the power of the being who they came from.
And so, the Realms of the Masquerade are in constant conflict with each side trying to prove their superiority over the other. Though this does not mean they shall not interact with the World and mortals. The Masked Beasts, the Abyssians will appear in a shower of destruction and conflict seeking only to destroy and find opponents to overcome and prove their superiority over, earning glory and potentially the right to challenge a Domain’s master for power. The Masked Courtiers, the Maledars however, will seek to find useful pawns by brokering deals and ensuring that their pieces are always available for whatever plots they need to carry out in the World.
Both sides will also take mortals from the World or souls from the Realms of the Dead and bring them to the Realms of the Masquerade for conversion. As any soul that consumes the blood of a Masked Evil will in turn become one themselves a member of the same thirteenth bloodline as the Masked Evil whose blood they consumed. The more willing the soul is, the less painful the transformation.
There are 28 Realms of the Masquerade. Thirteen are ruled over by each of the thirteen Archabyssals of the Masked Beasts, another thirteen are ruled over by the thirteen Archmalevolents of the Masked Courtiers. One realm remains unclaimed, but none venture to that barren realm. The final realm remains barred to all who try to enter and only the Archmalevolents and Archabyssals those who were born from the bisection of their primogenitors by the Eternal know of its purpose and importance.
There are 13 bloodlines for the Masked Evils each originating from the original 13 Archevils. This means for every individual bloodline there are both Masked Courtiers and Masked Beasts who can trace their origins in the bloodline.
This is reflected in the masks that form their part of each of the Masked Evil’s physical form, with no Evil having a completed mask as it shows which part of the sundering they are from. With it covering the right side of a Masked Evil’s face if they are a Masked Courtier and covering the left side of their face if they are a Masked Beast. The general form of the mask will be identical between members of the same bloodline with small details like scratches, scars, colouration, texture, and pattern being unique to the demon and devil born from the same sundering.
The 13 Bloodlines are:
The 14th servant of the Eternal that made the Masked Evils, escaped their creator’s wrath. They were never cut in half like their kin, but they were wounded. Each drop of their blood created a Masked Evil who was more powerful than any Masked Evil of the same rank born to those of the other thirteen bloodlines.
The 14th Archevil now travels creation seeking to grow stronger by fighting against the mortals and hoping to learn the secrets of their power. As if they could master that power, they could defeat their creator and free their kin from their eternal battle. The Masked Evils of the 14th bloodline are rare to find but can be found in service to both sides of the Masquerade or even travelling and fighting for other causes they find suitably interesting or relevant to their goals.
The Realms Primordial is the term given to describe a collection of Realm groups. Each of these are tied to the elements. These are:
The Outer Realms Primordial:
The Inner Realms Primordial:
Finally the Cosmic Realm.
Each of these are a grouping of Realms tied to their element further divided into Domains whose Masters are the Primordial Titans.
Connecting the Realms of Water and the Realms of Air are the Realms of Wood also known as the Realms of Life. Connecting the Realms of Fire and the Realms of Air are the Realms of Thunder also known as the Realms of Storms. Connecting the Realms of Fire and the Realms of Earth are the Realms of Metal. Connecting the Realms of Earth and the Realms of Water are the Realms of Fungi also known as the Realms of Decay.
Then connecting to all 8 of the Realms is the Cosmic Realm, also known as the Realm of Aether, Magic, or the Void.
It is said every World’s World Soul controls the four outer elements and four inner elements that have combined to make up the World, to keep balance and allow a World to thrive with life. Worldspeakers often train to channel the four outer elements as part of their training, with some choosing to train to master one of the inner elements which can prove a difficult task, while others will maintain their studies of the outer elements to master one of the outer elements or in rare cases all four of them.
The Cosmic element however is something only the World Souls have been known to be able to channel directly, with World Speakers who gain power from that Realm needing to channel it via the World Soul, a feat even Eternals have generally been unable to accomplish. It is only a single Realm, but nothing exists there, and none have dared explore it.
The Outside defies all rules of logic and understanding. The goals or objectives of its denizens, the Outsiders, especially regarding creation and its occupants, are alien and unknown to those who reside in the World. But there are some mortals who chose to devote themselves to powerful Outsiders for power, knowledge or to summon them for powerful servants. These actions usually lead to death for the mortal and a lot of destruction.
There are some denizens of the Outside who after prolonged time near the border between creation and the Outside become more akin to a denizen of reality. However, this makes them more dangerous as these entities are more likely to seek to enter and then conquer or destroy creation.