This is where you can post your ideas for the C.A.C. contest I am running. Anyone is free to contribute, even non-contestants. Check out the contest here!
Import-a-feature: Its hard to be totally original anyway, so instead of fighting it, embrace it. Find a feature from another game and find a way to incorporate it into the TCG. To give an idea, many concepts not part of the original Pokemon TCG, like PokeTools, Stadiums, and the Lost Zone are common place to games like Magic or Yu-Gi-Oh.
Quick note: Just because I did not choose your idea for this round does not mean I won't use it in some other round. I may also combine some ideas together.
How about:
Make a card, or group of cards, that win the game in a way other than doing straight damage, such as milling, status conditions, lostzoning, erasing your opponent's field, devolving, damage with an effect, etc.