Urza, Lord High Artificer

When Urza, Lord High Artificer enters the battlefield, create a 0/0 colorless Construct artifact creature token with "This creature gets +1/+1 for
each artifact you control."

Tap an untapped artifact you control: Add {u}

{5}: Shuffle your library, then exile the top card.
Until end of turn, you may play that card without
paying its mana cost.