I just play against that team (CC/Anex/Yoshiro). Yes, these cards are usually used by players, but its good. You can create deck against "usually used cards" and win, hehehe
Trading isnt so good for kongai. Now, with challenges and weak chance to win a card is really good. But in this game you must have a little to much luck than strategy to win. Second but, its fun, so ok :)