i agree with hahool340 that kongregate should make it so that you can:
1. a trade room where you can trade cards
2. tag team battles, where you battle with a partner.
3. private rooms and battles where you have to type a password to get in
4. a button to reset your starters.
and another good idea: increase the drop rate of cards for the 5 card battles.
2. make it so that you can play 5 card battles on ranked.