Spirit originally native to a planetarium; one of many. Was a constellation within the planetarium; her sister was one of the projectors. Planetarium crowded with them (ex. one was the darkness needed to run the shows, one was a particular echo effect of the dome, one was the moon crossing the projection, etc.)
Finite! But not mortal. Will end someday.
Sometimes when sleeps ends up projecting self on lair's walls or ceilings, like a night light.


Hall of Lights and Shadows: a large (room? cavern?) in the lair where the lair/ clan's living lanterns like to roost and where the clan members that are light like to gather (spirits, constructs, just glowy or firey, etc.) The lightning spirits like it in there too sometimes.
So sometimes the light and dark in there flickers and swirls and moves and competes, with all the different living sources of illumination either playing or passively existing or fighting.