Text (MR+errata): {4},{Tap}, Sacrifice ~this~: You control target player's next turn. (You see all cards that player could see and make all decisions for the player.) [Oracle 2009/07/08]
You control the entire turn, from untap step to the cleanup step. This includes playing spells, abilities, declaring attackers, assigning combat damage, and so on. [Mirrodin FAQ 2003/10/01]
You can see everything that player can see but you normally could not, including that player's hand, face-down creatures, and any cards in his or her library that they are allowed to look at. [Mirrodin FAQ 2003/10/01]
You can take control of your own turn, but this has no real effect. [Mirrodin FAQ 2003/10/01]
You cannot make the other player concede. [Mirrodin FAQ 2003/10/01]
If another effect occurs that takes control of the player's actions, such as Defensive Formation taking control of combat decision, then the other effect takes precedence. [Barclay 2003/10/10]
