Digesting Tar

Bestow {4}{b} Wither {I}(It deals damage to creatures in the form of -1/-1 counters.){/I} Enchanted creature gets -X/-X, where X is equal to the number of enchantments you control. When this card is sent from the battlefield to the graveyard, if it was a creature, you may pay 5 life and exile another creature from your graveyard. If you do, attach it to target creature as an aura.