While all my characters are technically part of Dream World, as it is the culmination of my entire creative endeavors, this is a world specifically for the characters who are either...
* Critical to understanding the overarching lore of the island
* Have lore that is connected to visiting the island (Or they just like to hang out)
This world is SEMI-OPEN to join requests. It primarily exists for organization, but if you're a friend of mine, you can ask about joining this world as well!

This text blurb goes into detail on four particular things: The multiverse and how I see it as a whole; Dream World, the fictional island that acts as a hub for my OC's universes; the Thoughtmaker, the leader of Dream World and her role, as well as the Thoughts, the individual characters themselves; and the Seer, which is me, and how I play into all of this.

The Multiverse
In my eyes, the Multiverse is an endless, dark blue void that's similar to what we perceive the universe or the night sky as.
Inside the Multiverse, there are many universes, separated as large, expansive clouds of light.
Within these universes, there are an infinite amount of different dimensions, differentiated by in-universe changes that cause enough separation from the core dimension.
Within those dimensions, there are endless timeline strings, representing the more subtle changes.
I judge the distance between universes depending on how close they are to Earth, the "center" universe for the sake of this model. The more similar a universe is to our Earth, the closer it is, and vice versa. For example, universes like Scott Pilgrim would be very close to Earth, while universes such as Pokémon would be quite a ways away.

Sister universes are universes that technically reside within a pre-existing universe, but are large enough to be their own separate entity. Deltarune and the Earthbound Halloween Hack are some good examples of this.
There's also what's known as pocket dimensions, or small, individual dimensions that are connected to another dimension within its universe. The Badlands is a good example of this, being a pocket dimension that's connected to Hopeverse, one of my original dimensions.
Worlds are another occurrence; small, individual, dimension-sized universes that aren't tied to any particular pre-existing universe. Dream World itself is a good example of this, as well as the five worlds Chi and Serik watch over in their corner of the Multiverse.
Open universes are basically crossover universes (the term is a work in progress), where they are designed to inhabit more than one pre-existing universe. Super Smash Bros. and Kingdom Hearts are the two best examples of this concept that I can think of.
If there is a phenomenon where a particular group of universes are known to reside within the same proximity and can interact with each other more frequently because of it, this is what's known as a Pantheon. Disney (Kingdom Hearts), Nintendo (Super Smash Bros.) and Square Enix (Final Fantasy XIV) are good examples of Pantheons.

Dream World
Dream World is a World of mine that I created in 2010, and it was my first real creation. It is a floating island that resides high up in the sky above the cloud line. Time passes normally here; the sun rises and sets (as does the moon), you can see the stars, etc. Formerly there was another island a ways away known as the Doom World, and an afterlife concept known as the Spirits (no, not the ones from SSBU), but both of these have since been scrapped.
Dream World acts as a hub for the Thoughts, or the individual characters that I own. It's its own separate World, but acts as an interdimensional hub/safe space for characters within the Multiverse. It's a second home; they can live here, sleep here, and just generally enjoy themselves on this peaceful island. Characters can move between Dream World and their own timelines as they please, which is a big help if their world is paused (frozen in time for whatever outside reason); Dream World gives them somewhere to be. If a character ever wants to travel to Dream World willingly, all they have to do is wish for it, and a portal to the island will appear. Dream World is like a utopia, in that there aren't any threats (...most of the time) and nothing... ever really changes.

The Thoughtmaker resides primarily on this island, and has quite a few abilities tied to Dream World itself.

Thoughtmaker
The Thoughtmaker is the title given to the leader of Dream World; they possess the ability to control the Thoughts and manage everything on the island. Currently there are only two Thoughtmakers that have ever lived: Wings, a phoenix who originally led the island, and Wings Hearthstone, the current Thoughtmaker. A few other entities who have ties to the Thoughtmaker also possess some of these abilities (Aurora and Amelia being the primary examples); The Seer, being the creator of the island, holds all of the Thoughtmaker's abilities, but she herself is not the Thoughtmaker.

The Thoughtmaker has the ability to control the Thoughts with their hands, moving them around and calling upon them for aid, or to attack any nearby enemies in a flying swarm of glowing orbs. They can check on a character's health/well-being by conjuring their Thought and see if they're in critical condition. There are a lot of elaborate hand motions (and a few shouted commands) that the Thoughtmaker uses to control the Thoughts.
The Thoughtmaker can also open portals to other worlds, whether it's to watch through and observe another universe (this is done in 99% of cases, and these portals are known as windows), travel between worlds or to actually interfere with another world and, say, save a character from their untimely demise (though this is seen as a last-resort option).

Thoughts
The Thoughts themselves are actually just orbs of bright light that can vary in size between fitting in the palm of one's hand to growing as big as someone's head. There's not much to say about them; a single character is a Thought, and they can be reverted from their normal form to their Thought form with a swish of the Thoughtmaker's hand. To check on a character's well being, the Thoughtmaker can summon the character's Thought above their chest and the glow of the orb will tell them how they're doing. As previously mentioned, the Thoughtmaker can cause them to swarm around an enemy for attacking purposes, or around an ally to slow down a fall or something of that nature.

The Thoughts also like music, and will pulse to the beat of a song or change their glow based on the volume/vocals of a singer. They're very similar to the light given off by a disco ball in appearance.

The Seer
Now here's where I come into play! For the sake of this, I'm going to be referring to "Galileo Windsong," or "Gale," who is my self-insert. She's the creator of the island and the Seer of Dream World. Here's what that means.

The Seer is the prime connection between Dream World and Earth, possessing the ability to see into other dimensions and see what's going on with its members, once their connection to any member is strong enough. Gale is also known to have premonitions and visions related to the Multiverse, usually of alternates of her own timeline. When I'm roleplaying, I can see what happens in my head (which has happened since the very beginning); in Dream World this is shown with the windows, allowing the Thoughtmaker + Dream World to see what's going on as well (including my own timeline). The other person's responses impact what's going on, and then I get the mental image, and the cycle continues. It's quite interesting to watch my characters, hear their conversations, see what goes down there and in Dream World, etc., etc...
That said, I am still a creator. These are all still my creations; they just have more life to them than I ever thought possible.

As previously mentioned, most Thoughts possess a two-way connection with Dream World; they can come and go to the island as they please, and I get to watch their shenanigans and potentially interact with them myself on the island through Gale.
[Note: If a character wants to see what happens on Earth, it's easy. If they're in their own dimension, if a TV is around, they can watch through the TV. If they're in Dream World, the windows work just fine, and have actually been used before.]