I remember all the cards from ccg's, LCG's and just plain card games that were never used due to building a "killer" deck.
So years ago I developed what was termed the "Generic" card game
The basic rules are simple:
Add the number of basic colors (not shades) to any numbers printed on the card and that is the cards strength.
Play with "war" rules, highest card wins, one with most tricks taken when you run out of cards is the winner.
The advanced rules require a calculator and creativity.
black x1 number total