As Cloud Key enters the battlefield, choose artifact, creature, enchantment, instant, or sorcery. Spells you cast of the chosen type cost {1} less to cast.
"A key only unlocks a door. Its wielder must choose whether to cross the threshold."
—*Hurkyl's Metaphysics, vol. II*
![Cloud Key (Retro Schematic) (Serialized) [The Brothers' War Retro Artifacts]](http://tothetablebgc.myshopify.com/cdn/shop/files/f8f539c4-9b68-49c2-b750-e4afa80d5178.png?v=1776662764&width=1445)
