Art by Bruce Pennington |
Some Dying Earth stories have more than a touch of the Gothic to them (Clark Ashton Smith's Zothique stories immediately come to mind), so this is really a natural. As the sun dimmed and sputtered, the Dark Powers grew stronger and fed upon the energy of the planet, slowing leeching it of life. Replace the sorcerer-kings with the Dark Lords, and (probably) loose the mists. Some tweaking of the domains might be in order, to make them a little less Dracula and a little bit more Vathek, but that's up to you.
Planet of the Vampires [Spelljammer/Ravenloft]
Each domain is a world, and the mists and phlogiston are combined into one. Maybe give Spelljammer more of a 18th Century or even Victorian vibe: Combine Kipling (his sci-fi stories like "With the Night Mail" and his horror yarns) with Stoker.
And why limit myself to AD&D settings?
Terror Under the Eternal Sun [Hollow World/Ravenloft]
I'm thinking ditch most of the Hollow World idea, except for it being the repository of things preserved from the outer world. Take it back to it's Burroughsian roots and have a land of dinosaurs and mostly primitive peoples, except for these areas and mists containing weird, otherworld realms of madness. Probably the realms of dreads should be a bit smaller, maybe just a castle and a village in some cases. Like Turok meets Dracula.