Muzzio, Visionary Architect
Legendary Creature — Human Artificer
, 
: Look at the top X cards of your library, where X is the greatest mana value among artifacts you control. You may put an artifact card from among them onto the battlefield. Put the rest on the bottom of your library in any order.
Volkan Baǵa
Conspiracy (CNS)
• #23Rulings
The value of X is determined as the ability resolves. If, at that time, you control no artifacts, you won't look at any cards.
(wotc • 2014-05-29)
Rulings
The value of X is determined as the ability resolves. If, at that time, you control no artifacts, you won't look at any cards.
(wotc • 2014-05-29)