Special Guests

Whir of Invention

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Search your library for an artifact card with mana value X or less, put it onto the battlefield, then shuffle.

"Magic hat, I'm gonna be frank. What we need now is a twenty-ton tank!"

Secret Lair Drop

Kaladesh Remastered

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Search your library for an artifact card with converted mana cost X or less, put it onto the battlefield, then shuffle your library.