It would be a very good Idea for the future, to when you challenge another trainer to a battle to allow the 'challenger' to setup rules for the battle.

 

Aka how many pokemon versus how many.

Maybe it like a bit where "1 versus 4" and such. The challengee has to accept the rules, it would be good say for someone who is battleing their friend.

"See if you can beat my >insert pokemon name< with your whole team."

 

Also maybe remove the black out after a duel?

Along with possibly setting up a 'reward' system where players can put items (specifically items) up for barter. Winner gets both, loser gets known.

And make the loser give up a portion of their money to the winner. We already know when you black out you get sent back to a pokemon center and lose a portion of your money?

Maybe make that money go to the trainer - but prevent a black out.

 

The 1hp rule would be a good Idea. Like alot of games have when dueling. The battle is over but all the players pokemon are left at 1hp. Enabling the trainer to heal them up and continue on their journey.

+1 :)