The situation. I have a False Prophet and an Attrition. I have 1 untapped swamp. My opponent has a Wall of Blossoms, a Morphling, an untapped plains and an untapped island. Morphling attacks. I sacrifice False Prophet to attrition. Are there any legal targets for the ability, and if not, what happens? Since the sacrifice is part of the cost of the ability, False Prophet may be in my graveyard and there may be no creatures in play. In response, my opponent attempts Swords to Plowshares on my Prophet. Is this possible? Really confused.