9 cards where the card is tagged “turn-face-down”

Backslide (Onslaught #70)
Cyber Conversion (Doctor Who #38)
Illithid Harvester // Plant Tadpoles (Commander Legends: Battle for Baldur's Gate #76)
Ixidron (Commander 2019 #87)
Master of the Veil (Legions #43)
Mondassian Colony Ship (Doctor Who #590)
Optimus Prime, Inspiring Leader (2018 Heroes of the Realm #2)
Very Cryptic Command (Unstable #49d)
Weaver of Lies (Legions #57)

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