Nyx, Shadow Sorceress

When Nyx, Shadow Sorceress or another Wizard enters the battlefield under your control you may search your library or graveyard for an instant
or sorcery card with cmc less than or equal to
the number of Wizards you control. If you do
reveal it and put it on top of your library.
{s}{u}{b}{r}; Return target wizard from your
graveyard to your hand. You may activate this
ability only once each turn cycle.