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.

• Number: 49*
• Rarity: P
• Type: Instant
• Mana cost: XUUU
• Color: Blue
• Artist: Christine Choi