Why not make the elemental ring post "melting together" the prime material?? Like, all four elemental gods made their ring, rebelled, got charred and their realms got melted together into a ring that eventually coalesced into "our" world. That: 1)explains why "our" world is a mishmash of classical elements 2)makes a cute allusion to protoplanetary discs Also explains why lava exists and underground is hot, probably experienced by dwarfs - the melt isnt cooled yet.
