Not fireplaces, campfires or torches. Placeables that can be placed on existing objects to give the effect of being on fire. Or gas escaping from the sewers or mists floating about a graveyard or fog near a shoreline or swamp.
Fog hovering above the ground would improve the atmosphere of any eerie setting.
Several object currently have the option to show flames and/or fire. Make one invisible object with each of these properties so this can be used to easily ad special effects to other object (flaming chalice, for example). Also a similar object with a fog like animation would be much appreciated for graveyards, dungeons, sewers...
Lightning, fire, glowing light, eerie light, gas, fog, torch, sunbeam, sunlight, vortex, black hole, energy field, etc.