This spell costs less to cast if it targets an attacking or tapped creature.
Target creature's owner puts it on their choice of the top or bottom of their library.
The creature’s owner chooses whether to put it on the top or bottom of their library. If multiple cards are put into the library this way (such as when the spell targets a melded permanent), that creature’s owner puts all the cards on top or all the cards on the bottom. They put them in whatever order they wish, and do not need to reveal the order.
less to cast if it targets an attacking or tapped creature.