I think it would be interesting to implement a game mode along these lines:

- One (or both) players would actually be a group of players (I'm calling it group player).
- On GroupPlayer's turn, each of the players that make that group sees the game in their "Games on your turn" list and make a move, as usual.
- However, the move is not actually made. Instead, it counts as a vote in that particular move.
BrainKing waits for all the players in the group to vote (or until timeout).
- When this happens the move for the group is then obtained from the one that had the most votes. If more than a move gets the same number of votes, the BKR of the players that voted for it is considered and the one with the highest sum of BKR is selected.
- The game would have a discussion board accessible only to the group's members, where they could exchange tactics for the next move, for instance. In a game with two groups against each other, there would be two such boards, naturally.
- These games could also have public invitations - the invitation is open for a certain time (like tournaments) and people just join (either) group. When time is reached the game starts.

I know this would be some hard work to implement. But I think this would be interesting in some situations:
- teams could really play against each other, as a team. Right now, teams matches are just a bunch of individual games, where you don't even get to play against all the members in the other team. It would allow for different sized teams to challenge each other too
- (top) players could challenge a "collective mind", supposedly harder to beat. Imagine a "Player against the rest of BrainKing" kind of game.

Anyway, it's just a thought...