Invasion of Ikoria #190 March of the Machine Change Version Invasion of Ikoria Battle Siege (As a Siege enters, choose an opponent to protect it
Use discard, mill, and other effects to fill your graveyard, then rise form ashes in triumph
(5/1/2012) If there are no nonland cards left in that library, the opponent will exile all cards from their library, and Stolen Goods will finish resolving.
The Magic card Aerith Rescue Mission encapsulates that choice perfectly: you can either take the elevator, giving you three 1/1 Hero Tokens (representing Cloud, Tifa, and Barrett being ready to fight), or you can take the stairs, which lets you tap and stun up to three creatures (representing their cardio-induced duress)
As an aside, the Signets are significantly worse being that much more awkward to use immediately
Pay X generic mana