Yamir, No More Humanity

At the beginning of each upkeep, if no
spells were cast last turn, create two
2/2 green and red Werewolf creature token.
{2}{w}{w}: Your opponents can't cast spells
this turn. Until the end of your
next turn, each opponents may cast spells
as though they had flash. (You can only use this
ability once until the beginning of your next turn and
only during an opponents turn.)