HEROES OF IMPILTUR
Genasi are a race with a combination of human and elemental traits. Every genasi constantly manifests an element state. A genasi’s body is etched with energy lines that glow in a color associated with the element that the genasi is manifesting. The energy lines on a genasi’s body appear in a pattern that is common between members of the same family and sometimes between natives of the same area. The specific configuration of energy lines on each genasi’s face and head is distinctive, varying between individuals the way fingerprints differ between humans. Genasi skin tones and “hair” also vary depending on which element an individual is manifesting. Genasi personalities vary greatly and are partially dependent of the elemental manifestation of the individual.
There were small numbers of genasi residing on Faerun prior to the Spellplague but by-and-large they lived on a different world. When the Spellplague transposed entire continents between worlds, a large number of genasi cities and their populations got relocated to Faerun.