Cloud Key

As this artifact enters, choose artifact, creature, enchantment, instant, or sorcery. Spells you cast of the chosen type {Lns}cost {1} less to cast.{flavor}“A key only unlocks a door. {Lns}Its wielder must choose whether {Lns}to cross the threshold.” {Lns}—Hurkyl’s Metaphysics, vol. II{/fontsize-6}