27 cards where the colors is U and the card has the keyword “Vigilance”

A-Geology Enthusiast (The Brothers' War #A-289)
Bay Falcon (Mirage #54)
Court Hussar (Masters 25 #51)
Duelist of the Mind (Outlaws of Thunder Junction #45)
Furtive Analyst (March of the Machine #59)
Haunting Figment (Dominaria United #53)
Hermitic Nautilus (The Lost Caverns of Ixalan #58)
Icewrought Sentry (Wilds of Eldraine #55)
Malcator's Watcher (Phyrexia: All Will Be One #58)
Marauding Sphinx (Outlaws of Thunder Junction #56)
Meldweb Strider (Phyrexia: All Will Be One #60)
Mirelurk Queen (Fallout #33)
Oaken Siren (The Lost Caverns of Ixalan #66)
Picklock Prankster // Free the Fae (Wilds of Eldraine #64)
Rangers of Ithilien (The Lord of the Rings: Tales of Middle-earth #66)
Referee Squad (March of the Machine #327)
Serra Sphinx (Double Masters #68)
Slickshot Vault-Buster (Outlaws of Thunder Junction #68)
Star Whale (Doctor Who #55)
Steamcore Scholar (Murders at Karlov Manor #71)
Twining Twins // Swift Spiral (Wilds of Eldraine #240)
Urza, Powerstone Prodigy (The Brothers' War #69)
Vhal, Candlekeep Researcher (Commander Legends: Battle for Baldur's Gate #102)
Waterlogged Hulk // Watertight Gondola (The Lost Caverns of Ixalan #83)
Waterlogged Hulk // Watertight Gondola (The Lost Caverns of Ixalan #83)
Xerex Strobe-Knight (March of the Machine #85)
Zephyr Falcon (Fifth Edition #137)
Zephyr Singer (March of the Machine #86)

The message was clear to Sorin—time to search for something else.