[quote=The WIP sphere rules in the doc]
As a caveat to the previous paragraph, some Spheres might not adhere to Euclidean geometry. They could overlap with others; in this way there might be a Sphere that acts as a fairy world, existing in the same place as Galbar but only becoming visible under certain conditions and only being accessible through the use of certain rituals or gateways.
[/quote]

Is there a reason why a more earthly sphere cannot take the above caveat and just pick whether it's more celestial or cthonic?