(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I = Urza's Saga gains "
: Add
."
II - Urza's Saga gains "
,
: Create a 0/0 colorless Construct artifact creature token with 'This creature gets +1/+1 for each artifact you control.'"
III - Search your library for an artifact card with mana cost
or
, put it onto the battlefield, then shuffle.