“Text” refers only to text in a card’s text box. Most keywords don’t do anything extra while doubled, but Berserking, Cat Form, diplomacy, inspire, and War Stomp do. In general, doubling a payment power does nothing extra unless it can be used only once per [period], in which case the doubled power can also be used once per [period]. If two Staffs are in play, the second one does nothing (except double the printed text of the first), because all other cards in play already have their printed text a second time.