Proserpina -- I like that pretty well.
Firmament -- That has a lot of positive things about it, but it also sounds descriptive rather than like a unique place you've never heard of before. In the case of this naming goal, I'd reject Middle Earth, but be inclined Narnia, if that helps. Not that I don't like Middle Earth as a name -- it's awesome -- but it's a different feel from what I'm vaguely searching for here.
Cascadia -- I like that a lot as the derivative. I think that's stronger than jut Cascade, but that's just me.
And yeah, ending in something other than "a" or "ia" is hard. I really love the name Ivalice partly because it's so unusual with that ending. Cascadice sounds really odd, though.
The Shelf -- that's pretty cool, actually. Though it's more of a descriptor than a place name. It reminds me of The Bastion, which isn't a bad thing, but I think it (and the others like that) are a bit off-tone here. I'm looking for something that's a bit more mythological-sounding, or like something from high fantasy without being goofy.
Caelumno -- That one's pretty cool, and I know the root from latin quite well. I think that "ae" sound is a bit harsh, though, at least if you pronounce it the proper latin way. Doing something based off the partial word "lumno" or similar could be strong, though. And yeah, I'm quite fine with something that sounds non-english.
"Sora wa" -- Ah, thanks for the clarification on that!
Estroth -- That's a pretty strong one.
Astadus -- That seems close to a strong one, but something about the middle bugs me. As*dus or As*us could work well, though, depending on what letters replace the star.
Fanerth -- I'm not keen on this specific thing, but something on these lines could be really promising.
