I wouldn't want to go too deeply on something like this, but a fun-of, one-of can go a long way
A good example would be the " Innistrad: Crimson Vow printing of Thalia
You may ask - whats this based on
: Level 3 Whenever you gain life for the first time each turn, put a +1/+1 counter on each creature you control
Wizards of the Coast releases multiple new expansion sets and supplementary products annually, each introducing hundreds of new cards and numerous variants, ensuring the games collectible universe continues to grow
The concept is very simple, but it works, and feels like a far more practical implementation than lets say, a battle card