Wistfulness

Creature — Elemental Incarnation

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.)