Wistfulness [Lorwyn Eclipsed]

Cost: 3 G/U G/U When this creature enters, if G G was spent to cast it, exile target artifact or enchantment an opponent controls.
When this creature enters, if U U was spent to cast it, draw two cards, then discard a card.
Evoke G/U G/U (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)