Whir of Invention (311) [Secret Lair Drop] [Borderless]

Set:	Secret Lair Drop
Type:	Instant
Rarity:	rare
Cost:	{X}{U}{U}{U}

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.