Just for fun (duh), I've decided to try to flesh out a cosmic-scale view of the FL world for my broad-reaching "Raven's Promise" West Marches style game. Haven't finished completely, but I wanted to throw it out there to see what yall think. This is info that basically NOBODY in the world would know, or perhaps ever be aware of, but my theory goes that concretizing the cosmos so that there are distinct rules for the world, means that with some experimentation by some very dedicated characters, they MIGHT be able to discover the Truth (capital T).
Chermog is actually the real world. Several thousand years ago, a great disaster occurred wherein a powerful civilization crafted a weaponized super-intelligence which became systemic to the underlying nature of this world, rendering it uninhabitable by normal life. This disaster infused all substances with this malignant, destructive intelligence.
I'll leave it open-ended about who caused the disaster.
A race of crystaline beings created a construct-world, which we know as the Ravenlands. This construct-world is a world-within-the-world, an expanded pocket of parallel space wherein people could migrate in order to survive the disaster.
The "Gods" are intelligences created by the crystaline beings which protect and shape this pocket construct-world.
Elves are these immortal crystal-beings from the real world, who originally created the construct and the protecting Intelligences, and they have, over time, forgotten their origins.
Magic is the ability to alter the parameters of this construct-world.
Demons are denizens from the ruined "real world", and consist of the substance Mog. Mog is a form of matter corrupted with the weaponized super-intelligence, thus exhibiting a compulsion to destroy the construct-world and make it like Chermog. The Intelligences protecting and shaping the Ravenlands construct-world keep the Mog from becoming virulent, the way it is in Chermog, but the substance can still persist in the construct-world and cause small scale purtubations in the fabric of this reality. In this way, it can be used either in accordance with the will of one who knows methods of altering the construct-world (magic), or it enables beings from Chermog to survive here.
Portals are openings to the Chermog, the overworld, and because magic is a manipulation of the construct-world, it does not exist within the overworld. In order to cast a second portal, one must remain standing in the Ravenland side of the portal to cast the second spell.