I see how making one sprite with different animation frames could work. However I still do feel stuck.
I'm not sure how I could get a card slot from the battle slot to choose which animation frame to be from the 8 selections. Is there a way to choose from the eight cards that are selected by the players, and change that specific sprite to a random one of those frames?
This is probably on me, but I also don't see how the instance variables would work in that situation. Even if all of the cards in the deck had a "deck=1" instance variable, is there a way to change the sprite to a random animation frame from all of the cards with the "deck=1" instance variable?