Prism Rain is a Shotlock that is exclusive to Aqua in Kingdom Hearts Birth by Sleep. This Shotlock is similar to Ragnarok, but instead of beams of light, it shoots out rainbow-colored beams.
Etymology
A prism is a small glass that is used in science to reflect light at an angle until it's to the point where the light splits up into 7 different colors.
Location
Prism Rain is located in a chest in the Ship Hub in Deep Space.