the fighting dojo the one were u would normally get hitmonlee or hitmonchan
america
Yes, you can.
Yes you do
Find them on a certain day, time, and place and you will get their phone numbers. Then, on another certain day/time/place you can call them for a rematch.
After you defeat all 16 gym leaders, you can call them to arrange a rematch through pokegear in fighting dojo in saffron city(kanto). See related link below to get gym leaders phone numbers and when to call them.
it was about two or three of the gym leaders
You can either trade an onix holding a metal coat or wait until Whitney calls you after a rematch between you and her
Blackthorn and mohogany
at their gyms.....
At the Pokemon League, or at a Rematch with your Rival, or Gym Leader, or Ice Cave, Johto
you can't
rematch the gym leader's 5 times each and talk to mr Pokemon and he will say darkrai is roaming around johto or kanto