Have a look at https://boardgamegeek.com/boardgame/194607/mystic-vale where cards grow during the game. It's implemented physically.

> Mystic Vale uses the innovative "Card Crafting System", which lets you not only build your deck, but build the individual cards in your deck, customizing each card's abilities to exactly the strategy you want to follow.

You would probably want to go with fewer cards. But something like a deck builder could work.