X-Ray Vision is rare ability that allows the user to see through solid objects and matter. The only known magical being with this ability is Malcolm, the warlock who was trapped into painting by a witch named Nell.
History
The Painted World
In the 1920s, a witch named Nell trapped the warlock Malcolm into a painting. The incantation that trapped him in the painting was hidden behind the drawing so that only beings with this power could see and read it. Later in 1999, Prue Halliwell came into the possession of the painting and discovered the spell when she had the painting x-rayed. She read the spell aloud and got herself trapped.