Discworld has “Sourcerers...”—the eighth son of an eighth son is a wizard, and the eighth son of a wizard is a Sourceror, who acts as a source of magic and is capable of doing things ordinary wizards can’t. Unfortunately, too much magic in any one area breaks holes in reality and lets in Things from the Dungeon Dimensions, so any Sourceror ends up being a walking apocalypse waiting to happen. Which is also why Discworld wizards are celibate. ;)
Discworld has “Sourcerers...”—the eighth son of an eighth son is a wizard, and the eighth son of a wizard is a Sourceror, who acts as a source of magic and is capable of doing things ordinary wizards can’t. Unfortunately, too much magic in any one area breaks holes in reality and lets in Things from the Dungeon Dimensions, so any Sourceror ends up being a walking apocalypse waiting to happen. Which is also why Discworld wizards are celibate. ;)