The Myriad, properly, is everything. All of the infinite possibilities, every infinite variation. Its fabric, outside of any one local reality, has infinite spatio-temporal dimensions. From outside, in the fabric, the entirety of a given reality may be seen, both in space and time, if only one knows how to look. More colloquially, people refer to as the Myriad what is more properly termed the Idea of Humanity: that region of the Myriad home to and dominated by humanoid people. It is understood that all of these peoples, though they may go by various names - humans, elves, dwarves, orcs, maja, ansu, klingons, vulcans, twi'leks, zabraks, and so on - are in reality slight variations on the same theme. Though we may consider eachother different, we share a common mode of intelligence. This is why we can understand eachother's existences and ways without too much trouble. We can communicate without learning anything too arduous. We can fight eachother and understand why there is conflict. We can love eachother.
None of this is necessarily true for us when interacting with beings from outside the Idea of Humanity. Such beings are alien. Not simply foreigners with a different culture - truly, maddeningly Alien. Of course, the upshot of that is that we're just as incomprehensible to them, and if they're from different Ideas from eachother, they'll drive eachother mad, too. Also, the Ideas do not have hard borders. They bleed into eachother to a degree. This is why there exist realities in which both Humanity and one or more Aliens exist. Depending on the distance from the Centre, you can determine which one dominates.
As the name suggests, the Centre is the point from which the Idea of Humanity springs, where the Idea is at its strongest. The Centre itself is controlled by the Three, but in the region immediate to it, human will and narrative reign supreme. Whatever our minds dictate is most sensical, both passively and actively, is reality. Farther away, this becomes less true, with cold, hard mathematical physics gaining more and more ground until there is reached what is known as the Silent Sphere.+It's not a 3-dimensional sphere, of course. It's the א-dimensional analogue of one.
In the Silent Sphere, the physics of local realities are so strict that Travel to these realities cannot be performed. As such, there can be no communication to or from them, hence the name. Even farther out, however, Travel becomes possible again, but realities become progressively more and more attuned to Alien Ideas, rather than to that of Humanity.
Travel is simply the power to exit a reality and enter the fabric of the Myriad, and vice versa. There is no technique to learn how to Travel. It is passed on simply by the act of it - if you are made to Travel, you will then be able to Travel on your own. While the basic capability of it cannot be learned, afterwards there is much for the novice Traveller to learn. Controlling such a power accurately is not the easiest of skills. One major rule of Travel in the Myriad to look out for is Translation. Different realities have differing physics, with the differences ranging from slight to great relative to other realities. The fabric of the Myriad takes a record of the information that comprises your being when you enter it. When you enter a reality with physics differing from those of your home, this information must be altered to fit said physics. Hence, Translation. Beware, Traveller. You may find your capabilities and even equipment changing to some degree or other depending on what sets of rules they must conform to, wherever you may be. Another interesting effect of Translation is one perhaps rather more literal to our minds - you will be able to understand any language spoken to you, and any language you read, if you have that skill. You will concomitantly be understood by all you speak to, and anything you write will be understood by all.
In the Centre lies the House, the monument representing both the Three and the moment the Three created the Idea of Humanity. The House has three walls, each is one of the Three. The roof of the House is three mirrors, reflecting when each of the Three was Created by the other two, as the Artisan and the Critic, entwining them all together. Inside the House lives the Sylph at the Centre, a mysterious oracle held in crystalline stasis, who only comes out to offer brief aid to those Travellers who have the wherewithal to reach her. The Three are, as mentioned, the Creators. They are not the only Traveller Gods, but they are the most powerful and influential - even lesser Gods pay homage to them. The Three are as follows:
The Phoenix King, Kandurinith. His prime aspect is Stasis. His elemental aspect is Fire, in which He is known as the Unconquered Sun. His existential aspect is Healing, in which He is known as the Warm Down. His economic aspect is Protection, in which He is known as the Great Wall. His social aspect is Order, in which He is known as the Eternal Circle. In Creation, He is the Anvil. His form is, as his name suggests, that of an immense fiery avian of indeterminate species.
The Shadegod, She of the Three Secret Names. Her prime aspect is Change. Her elemental aspect is Darkness, in which She is known as the Lady of Crows. Her existential aspect is Death, in which She is known as the Inevitable Mother. Her economic aspect is Destruction, in which She is known as the Transfixed Berserker. Her social aspect is Justice, in which She is known as the Revolutionary Knight. In Creation, She is the Hammer. Her form is that of a short feminine-shaped cyborg with pitch black synthetic skin, mauve-to-pink hair, and yellow eyes. Inside, She is not flesh and bone, but steel and electronics - save for Her only biological organ, Her brain.
The Impossible Wanderer, the Stormfront, the Eater of Realities, That Whose Name Has Been Excised. Its prime aspect is Madness. Its elemental aspect is Storm, in which It is known as the Roiling Child. Its existential aspect is Torment, in which It is known as the Warden and Prisoner. Its economic aspect is Consumption, in which It is known as the Blind Idiot. Its social aspect is Chaos, in which It is known as the Heartless Walker. In Creation, It is the Raw Material. Its form is thằ͝t͏ ͟øf͠ ÄḜ̸Ḝ͢/ $$҉Ⱦ͘ÖÖЯ҉Ɱ̸æ͎̰̰̲͖̹͙m̦̼̥ê̢͈͙̮̲̟̗̤͞͞╚͓̠̫̬̟͉̻4͇̻̙͙̩̥͓▌̷̨̩̩̺̘͡╩͔̟̲͈̦̻̩̰̜̕͟,̧̩̤̳̤̹͝║̙̞̱̝♥̡̛̗̼͚͍̪̟̥\̵̞̻ñ͙̦̝̤̘͈͝←̧̗̻̭̠̱ª҉̬̭̞͎̫̀͢ş̢͍̥H̨͙̖̤̮̭͘á̡̪̫̥x̟̱͖̖͇̱̞͞&̷͔̰͠↓̗͍̱̲ⁿ̧̢̜̣̳͞↛͖̥̕÷̷̦͈̣̤̯͎̗͢╞̨҉̝͇̪̱̘͉̱F͍̮͕̬͟p̬͚̱̗̟̰̺̮͘$͏͔͇̟̣̀w̹͔̞̘̻̰y̵̛͕̞̥̦̤̪͓͜Ö̢̪̞̜̱̼͙Ö̖͍̻̭͓À̡͏̤̙̣̗ ͔͈͙͈̟̥̦͎́ͅ╜̢̺̼̬͙͍̬̙̣̻͢͠║̸̨̧̩̲͍͍̞q̥̲̥͢͞O̢̤͚̥̬̫w̗͎̦̟̠̙+̜̜̰̹̭̭͡╥̧̲͈P̵̺̮̝
Important to understanding the natures of the Three are the concepts of omnisactuosity and omnicapacitance. None of the Three are omnipotent - that can only be achieved with their uniting as the Creator. Alas, that state is unstable. Omnipotence is fleeting. And so the Three, after the moment of Creation, separated once again. And so did omnipotence separate, into omnisactuosity and omnicapacitance. Omnisactuosity is a state of existence without limit on the kinds of actions one may take. Omnicapacitance is unlimited energy with which to take actions. The Impossible Wanderer is omnisactuose. It can do literally anything, and so it breaks all the rules of the Myriad by its very existence. However, It is not omnicapacitant. Its energy, its very existence, constantly drains away. In order to continue existing, it thus consumes completely any reality it comes across. The Phoenix King and the Shadegod, on the other hand, are omnicapacitant, but not omnisactuose. There are some hard limits, as dictated by the mathematics of the fabric of the Myriad,+For example, the injunction against being physically present in multiple places in personal simultaneity.
that even they must obey. However, within such limits, their power is otherwise endless.
In more esoteric understanding of the Three and their Creation, the Three's aspects are not the only aspects - there are thirty in total. Though the remaining fifteen do not have actual forms or intelligences behind them like those of the Three, they are known as the Demons of Imperfection, as they arise from the dual combinations of the Three, rather than the perfect triune of Creation. The aspects of the Three only combine within their respective categories.
At the intersection of Stasis and Change lies the Demon of Conflict.
At the intersection of Stasis and Madness lies the Demon of Domination
At the intersection of Change and Madness lies the Demon of Armageddon
At the intersection of Fire and Darkness lies the Demon of Stone
At the intersection of Fire and Storm lies the Demon of Sky
At the intersection of Darkness and Storm lies the Demon of Sea
At the intersection of Healing and Death lies the Demon of Life
At the intersection of Healing and Torment lies the Demon of Eternity
At the intersection of Death and Torment lies the Demon of Murder
At the intersection of Protection and Destruction lies the Demon of Survival
At the intersection of Protection and Consumption lies the Demon of Stealing
At the intersection of Destruction and Consumption lies the Demon of Growth
At the intersection of Order and Justice lies the Demon of Civilization
At the intersection of Order and Chaos lies the Demon of War
At the intersection of Justice and Chaos lies the Demon of Freedom