Conceptual Worlds

The Engines Of Reality
These dimensions, or maybe creatures, are also known as the primordials. They're semisentient conceptual locations, and they appear to be the source of their concepts. Destroy the underworld, and nothing will ever die again. This has never been tested but then, if a concept was removed, how would we know?

Anyway.

Unlike other planes, Conceptual worlds exist everywhere- the physical place is just the core. The Timestream exists anywhere time passes, and can be accessed from any of those places. They're sentient, but cannot or will not interact with mere mortals. As such, they choose mouthpieces, divine figures who speak through them and serve their will. Or so we assume.

It's hard to tell, with things that are to gods are gods are to us.

Major Conceptual Planes
The Underworld/Thanatos: the afterlife, and the place you go when you die. Its primary mouthpiece is Hades

The Realm Of Chaos/Khaos: the primordial realm of chaos and anarchy, its war with order defines the magical half of the cosmos. Its primary mouthpiece is Artimes

The Realm of Order/Phanes: the realm of order and stability. its primary mouthpiece is Apollo

The Pit/Tatarus: the realm of suffering and misery. Its primary mouthpiece is Oizya

Olympus/Nemesis: the realm of the Gods and higher powers. Its primary mouthpiece is Zeus.

The Dreamrealm/Morpheus: the realm of dreams and fantasy. It's primary mouthpiece is Dionysus

Fate/Moros: the realm of destiny and predestination. Its primary mouthpieces are the Fates

The Elemental Planes (earth, air, fire, water, light, darkness/Ouera, Uranus, Hermera, Pontus, Aethyr, Erebus) the building blocks of physical reality. No major mouthpieces

The Timestream/Chronos: governs the flow of time. No major mouthpiece.