9 cards where the block is “usg” and the text includes “untap up to”

Cloud of Faeries (Urza's Legacy #29)
Frantic Search (Urza's Legacy #32)
Great Whale (Urza's Saga #77)
Palinchron (Urza's Legacy #38)
Peregrine Drake (Urza's Saga #88)
Rewind (Urza's Saga #93)
Snap (Urza's Legacy #43)
Time Spiral (Urza's Saga #103)
Treachery (Urza's Destiny #50)

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