Creatures only exist on the battlefield; in every other zone they are creature cards.

Many spells and abilities affect creatures in some way or another. When text on a card refers to creatures, it means creatures on the battlefield. This is because creatures only exist when on the battlefield. When a creature card is in any other zone, it is just that: a creature card. For example, let's say that you control and you have in your graveyard. If you cast and choose to exile the Kemba's Skyguard from your graveyard, the Corpse Lunge will only deal two damage. Honor of the Pure will

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