What gwent card do you believe is the strongest ( or more useful in most cases { not necessary your favorite } ) For me its this : : r/witcher
Win the Gwent Card Battle against the halflings (Dead Man's Party) Witcher 3 Hearts of Stone - YouTube
This is one of the toughest Gwent players I've had to face. Literally had to play her 5 times using different factions and rearranging my deck mixed with luck to beat her