Drangonhawk with stun counter, cactusfolk sureshot and stingerback on the board. Another dragonhawk in hand. Drop the new dragonhawk to replace the one with a counter on it. Choose the old dragonhawk to get rid of (I know because the old one had a perpetual mana reduction (alchemy). The old dragonhawk goes into the graveyard and the new one drops on the board, takes the stun counter from the old dragonhawk and exiles 3 cards.