In ruby/sapphire/emerald beat the game. Before you go use your master ball, go to the battle tower at the battle frontier. When there, give 1 of your party Pokemon the masterball to hold. Then put it in the pc. Save your game. Take the same Pokemon out of the pc and go to the wifi counter of the battle tower. When you pick the Pokemon you want to use make sure you pick the one holding the masterball. In the middle of saving turn of the game. Turn the game back on and look in your party the Pokemon will still be there. Then look in the pc and you will find a perfect clone.do this until you have the amount of master balls you would like.
Turn the game off and, leaving the gba game in the slot insert Pokemon soulsilver. On the game menue select migrate pokemon. Pick the Pokemon you want to migrate. When you migate the Pokemon to soulsilve they will still have the masterball.
This cheat also works for platinum, pearl, diamon and heartgold.
Added by: m6_19982011 Jun 26th 2012, ID#17137