The most likely reasons are if it's sacrificed, if it's legendary and another legendary permanent with the same name is controlled by the same player, if it's a planeswalker and another planeswalker with the same subtype is controlled by the same player, if it's a creature with toughness 0 or less, or if it's an Aura that's either unattached or attached to something illegal
Can I browse by rarity or type
ST24-09 U Digimon Lv.4 Sunflowmon Color Green Cost 4 DP 5000 Digivolve Cost 1 Green 2 from Lv.3 Form Champion Attribute Data Type Vegetation/DATA SQUAD Card Text 1 [Special Digivolution Condition] [Digivolve] Lv.3 w/[DATA SQUAD] trait: Cost 2 [Effect] [On Play] [When Digivolving] You may suspend 1 of your opponent's Digimon or Tamers
) fairly easily Cons of BA Gearfried Can brick on too many Gearfried cards Not very strong at playing through backrow (though still better than pure BA) No room for techs Hazy Flame Gearfried Sample Hazy Flame Gearfried Decklist ExtraShoddy KoG Sep '23 Overview of Hazy Flame Gearfried Hazy Flame Gearfried also aims to put Beatrice on the board for defense and resource generation, and then toss Gearfried onto the board for good measure
Not only are they one of the coolest decks out there (being based off of the Star Wars movies), but they have some of the most powerful effects out there too
Also, like Legatia, it responds to not only Synchro Summons but also general special summons, so you can use the search effect without any problems even when using revival cards or Parangx