Legendary Creature - Human Wizard 3/4, 2UUU (5) Flash (You may play this spell any time you could play an instant.) Creature cards you own that aren't in play have flash. Each opponent can play spells only any time he or she could play a sorcery.1 To save this plane, he must forsake all others.
Illus. D. Alexander Gregory & Jeremy Jarvis
9/25/2006: The last ability means that in order for an opponent to play a spell, it must be that opponent's turn, during a main phase, and the stack must be empty. This is true even if the player doesn't have a sorcery he or she is able to play, or if a rule or effect allows a spell to be played at another time.
9/25/2006: If you have Teferi in play, you may remove from the game creature cards in your hand with suspend any time you could play an instant.
9/25/2006: If an ability lets an opponent play a spell as part of its effect (such as Isochron Scepter's ability does), that opponent can't play that spell since the currently resolving ability is still on the stack.
9/25/2006: Your opponents can't play their suspended cards, no matter what phase it is when the last time counter is removed. Your opponents can't play cards using the madness ability either, no matter what phase it is when the card is discarded.
5/1/2007: If you have Teferi in play and there’s a Split Second spell on the stack (such as Sudden Death, you can’t Suspend creatures until after the Split Second spell resolves.
Time Spiral
(Rare)