Try playing the EVO mode to level up your cards. Basically, the first player on the turn puts 6 pillz on his character he wants to level up, then the second player puts no pillz. On the next turn, it's the other players turn to put 6 pillz on his character and so on. You can check out the EVO way of at the Master's Tips page. It's a good way of leveling up your leveling your cards.