I think it would be fun to have a rare called Instant Win. If you play it you win instantly.
Make it even more rare than the current rares. Take however often the game gives out a rare and 1 out of a 100 of those times make that rare an Instant Win. In other words, make it a rare rare.
Then once you have it, make the game only put it in your deck every 100th or 200th game you play, and even then only about 20 or 30 percent of the time you hit that 100th or 200th game.
Give it a cost of around 200 or 300 random quanta.
