Ragaid

In the days of the Old Religion the High Priestesses used to perform a terrible punishment known as Ragaid, the ultimate warning from the sorceresses to their enemies. The disfigurement was the result of extremely powerful magic and caused the skin to grow across the victim's face until he suffocated. Morgana performed this magic on a Knight of Camelot to declare war to the whole kingdom (The Kindness of Strangers).