19 cards where (the text includes “hexproof” and the text includes “until”) and the colors is U

Dive Down (Ixalan #53)
Mizzium Skin (Return to Ravnica #45)
Shell Shield (Zendikar Rising #79)
Shore Up (Dominaria United #64)
You See a Guard Approach (Adventures in the Forgotten Realms #85)
Avalanche Caller (Kaldheim #45)
Battlefield Thaumaturge (Journey into Nyx #31)
Cradle of Safety (Innistrad: Crimson Vow #54)
Fae Flight (Murders at Karlov Manor #56)
Fleeting Reflection (Outlaws of Thunder Junction #49)
Glint (Dragons of Tarkir #55)
Lazotep Plating (War of the Spark #59)
Rattlechains (Crimson Vow Commander #110)
Starlit Mantle (Theros Beyond Death #67)
Water Wings (Wilds of Eldraine #77)
Sparkshaper Visionary (Commander Masters #726)
Mistfire Weaver (Khans of Tarkir #46)
Prognostic Sphinx (Forgotten Realms Commander #90)
Trench Behemoth (Commander Legends #366)

Their mind whirled with grand plans, never thinking of what might happen if they got to the end of the list.