The only world the Stellari know, The Grand Citadel.
Home of countless magi, world of the one-thousand and one gates. A webway of portals that connect seven country-large Towers; reaching into the aether and then back again, bless be magic and its weaving net. Battlefield of political turmoil, war and each tiny stellar dot of individual narrative.
In the Citadel, "sky" means "dome ceiling" and "star" means "light". There is no nature save from that carved out of mage hands, and then happily blue or pink just as well as green. What is a cat, really; it says it has claws, in this old text here, but does it have fur or scales? Common things of the material plane are distorted through the world's longest game of telephone--only distantly related to the original concept.
Apples are white and taste like spiced plums. But they have always been this way, surely. Right?