Teferi, Time Raveler
Oracle Text
Each opponent can only cast spells any time they could cast a sorcery.
+1: Until your next turn, you may cast sorcery spells as though they had flash.
-3: Return up to one target artifact, creature, or enchantment to its owner's hand. Draw a card.
Ironically, I think this card would "feel stronger" if it lacked the +1 ability altogether. Getting that static effect with a one-time bounce that cantrips is a VERY good deal... but the relative narrowness of that +1 kind of blindsided me.
Between killing mirror controls and enabling instant-speed wraths and thoughtseizes, this may actually be the strongest walker announced so far.
Most of all though this just super strong in control mirrors and is serviceable everywhere else.