Vesimir, Walking Cataclysm

Whenever Vesimir attacks, you may exile the
top card of each players library. If you do, cast
any number of nonland cards exiled this way
without paying their mana costs. Until the end
of turn, whenever you cast an instant or sorcery
spell, each other player copies that spell. Each of
those players may target any nonland permeant
that you don't control for his or her copy.
Even reality has the tenacity for madness