If damage would be dealt to Dralnu, Lich Lord, sacrifice that many permanents instead.
: Target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost. (You may cast that card from your graveyard for its flashback cost. Then exile it.)
9/25/2006 All of the permanents are sacrificed at the same time, when the damage would have been dealt. So if Dralnu is one of the permanents you sacrifice due to its first ability, you must still sacrifice enough other permanents to equal the amount of damage that would have been dealt to it.
9/25/2006 If you don’t control enough permanents, sacrifice all permanents you control.