Muzzio, Visionary Architect is a mythic Legendary Creature — Human Artificer card from Conspiracy (CNS), collector number 23. Current market price: $0.77 (foil $24.17), TCGplayer market prices via Scryfall.
{3}{U}, {T}: 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.