text: If any of the exiled cards has a characteristic-defining ability that defines its power and/or toughness, that ability will apply. For example, if you used Souls of the Lost to craft Wretched Bonemass, its power and toughness while in exile are determined by the number of permanent cards in your graveyard, and Wretched Bonemass's power and toughness will change as the number of permanent cards in your graveyard changes. If the characteristic-defining ability can't be applied, then use 0.