A cour'souvra, or mindtrap, is a device, favoured by the Shadow that allows the holder to control a person who can channel. They can only be created at Shayol Ghul. They are made from what appears to be a small cage of gold wire and crystal, to which is added a mixture of the person's blood and saliva, turning the crystal pink. To complete the process, it is thrown over the lake of golden stone, to hover over the place the Bore seems to be, until it glows brightly and the victim feels intense pain and feels as though they are blended with the cour'souvra (ACoS, Ch. 25).
The person who holds the mindtrap, is referred to as Mia'cova in the Old Tongue, "One Who Owns Me", or more simply, “My owner” Holding one gives a person a great deal of power over the victim, channeling near their own cour'souvra iss extremely painful, the nearer, the more the pain and very close, possibly not even survivable. If the holder lightly touches the cour'souvra, the person held feels it, like a touch across their mind, no matter how close they are. A slightly rougher touch, to break the mindtrap, and the part of them that thinks and feels would be separated, the body being totally under the control of whoever held the cour'souvra, able to move, hear, see and taste, but helpless (ACoS, Ch. 25).
In the Age of Legends, they were used on many people (ACoS, Ch. 25), but in the current age, only Moghedien (ACoS, Ch. 25) and Cyndane (WH, Ch. 35) are known to have one, which Moridin used to force them to Travel to Shadar Logoth and try and stop Rand cleansing the taint (WH, Ch. 35.