soul, spirit
靈 centers on the immaterial essence of a being: the soul or spirit. It refers to the animating, non-physical part of a person or entity.
靈 combines 霝 (a phonetic component associated with falling rain or spiritual communication) with 巫 (shaman), suggesting a shaman mediating with spirits. The exact historical development is uncertain.
Rain 雨 falls over a shaman 巫 performing a ritual: the shaman calls down the soul or spirit from the heavens.
For レイ, imagine a ray of light representing the soul leaving the body: ray -> レイ, and the spirit ascends.