Nova, Demanding Wisher

At the beginning of each opponent's end step,
if Nova, Demanding Wisher is untapped, they
discard a card, sacrifice a creature, and lose 3 life.
{t}: Nova's controller searches their library
for a card, shuffles the library, and puts that
card on top. Only opponent's may activate
this ability and only as a sorcery.
"My wish is your command" - Nova