you can only battle battled trainers if you registered them in your pokegear.call them,if they want to battle,they'll tell you.
I suggest challenging the elite four over and over again. You gain the a lot of experience in a short amount of time. Also use the Vs. Seeker on trainers you have previously battled that gave you a lot of experience such as trainers on the islands that are open to only trainers that have beat the elite four.
They can be battled again if u haven't recruited them and u can also get the treasures again.
You can't
Yes trainers can rematch you in Pokemon crystal but you must register there phone numbers to do that but not all trainers will rematch you, wait until the trainers call you they will mention they want to battle again and they will remind you where they are go there and talk to the trainer to battle them again. They can keep calling you for rematches throughout the game don't miss the chance to rematch them.
you battle trainers again by adding them onto your pokegear and then soon they will want a rematch
No, you can't. -Tomas
no
Yes
you cannot. you can only fight them once,
They are custom made Nike's.
Well you can't find it again if you saved your game before battling it you can reset your game and try catching it again.
if youve have battled him at dragons den. you can battle him again in indigo platou on mondays and fridays