Wizards of Ertshea

At some point before squaring off against P.R.O.B.E., the Greth attempted to invade Ertshea, later claiming the title of "Scourge of the Wizards of Ertshea". (PROSE: Out of the Box)

Behind the scenes
The name of Ertshea is reminiscent of, the setting of 's highly influential , the first book of which was entitled.