Teferi, Mage of Zhalfir | Magic: The Gathering
Formats Teferi, Mage of Zhalfir is Legal in
Official Oracle Text for Teferi, Mage of Zhalfir
Creature cards you own that aren't on the battlefield have flash.
Each opponent can cast spells only any time he or she could cast a sorcery.
Official Rulings for Teferi, Mage of Zhalfir
9/25/2006 : If you have Teferi on the battlefield, you may exile creature cards in your hand with suspend any time you could cast an instant.
9/25/2006 : If an ability lets an opponent cast a spell as part of its effect (such as Isochron Scepter's ability does), that opponent can't cast that spell since the currently resolving ability is still on the stack.
9/25/2006 : Your opponents can't cast their suspended cards, no matter what phase it is when the last time counter is removed. Your opponents can't cast cards using the madness ability either, no matter what phase it is when the card is discarded.
5/1/2007 : If you have Teferi on the battlefield 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.