33 cards where the text includes “flash” and it’s legal in Commander and the text includes “though they had flash”

Emergence Zone (War of the Spark #245)
Leyline of Anticipation (Commander Legends: Battle for Baldur's Gate #726)
Shimmer Myr (Commander Masters #409)
Sigarda's Aid (Commander Legends #384)
Vedalken Orrery (Double Masters 2022 #317)
Alchemist's Refuge (The Lost Caverns of Ixalan Commander #318)
Teferi, Time Raveler (War of the Spark #221)
Vivien, Champion of the Wilds (Commander Legends: Battle for Baldur's Gate #838)
Liberator, Urza's Battlethopter (The Brothers' War #237)
Yeva, Nature's Herald (Duel Decks: Elves vs. Inventors #27)
Wizards of Thay (Commander Legends: Battle for Baldur's Gate #105)
Raff Capashen, Ship's Mage (Commander Masters #351)
Tidal Barracuda (Commander 2020 #39)
Quick Sliver (Commander Masters #907)
Renari, Merchant of Marvels (Commander Legends: Battle for Baldur's Gate #90)
Gandalf the White (The Lord of the Rings: Tales of Middle-earth #19)
Borne Upon a Wind (The Lord of the Rings: Tales of Middle-earth #44)
Heliod, the Radiant Dawn // Heliod, the Warped Eclipse (March of the Machine #17)
Heliod, the Radiant Dawn // Heliod, the Warped Eclipse (March of the Machine #17)
Arlinn, the Pack's Hope // Arlinn, the Moon's Fury (Innistrad: Midnight Hunt #211)
Arlinn, the Pack's Hope // Arlinn, the Moon's Fury (Innistrad: Midnight Hunt #211)
Rattlechains (Crimson Vow Commander #110)
Skittering Cicada (Commander Masters #717)
Winding Canyons (Weatherlight #167)
Gandalf, Friend of the Shire (The Lord of the Rings: Tales of Middle-earth #50)
Aluren (Tempest Remastered #165)
Breath of the Sleepless (Crimson Vow Commander #11)
Najal, the Storm Runner (Dominaria United #208)
Hypersonic Dragon (Iconic Masters #201)
Complete the Circuit (March of the Machine #52)
Singer of Swift Rivers (The Lost Caverns of Ixalan Commander #98)
Vernal Equinox (Mercadian Masques #283)
Cherished Hatchling (Rivals of Ixalan #124)
Sally Sparrow (Doctor Who #155)
Rootwater Shaman (Tempest #84)

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