At the beginning of your end step, put the top seven cards of your library into your graveyard. Then return a card at random from your graveyard to your hand. Whenever you roll , return target card from your graveyard to your hand.
Official Rulings for Nephalia
6/1/2012 : Nephalia's first ability doesn't target any card, and players don't get priority to cast spells or activate abilities in between putting cards into your graveyard and choosing a card to return.