Dark Worlds

Even the gods themselves at the peak of their powers are not immune to failure. Of the myriad worlds which are founded within the vast Astral Sea, a small portion prove to be more unstable than initially projected. Whether through some internal flaw or shifting external forces, the destructive energies of the Astral Sea eventually tilt and tip into these failed worlds, washing them clean, utterly erasing them and returning their light and matter to the Sea's churning substance.
Many of these worlds are very similar to more stable prosperous worlds but differ on some few key points.