you need to beat all 8 johto gym leader then go to the dragons den talk to elder answer his questions exit elm calls you. then he'll give you the master ball
professor elm gives it to you..
Duplicate Pokemon with a masterball attached to them.
After defeating Team Rocket, you need to go to Prof. Elm. He will give you a Masterball if you talk to him.
After you have defeated all 8 gym leaders, go to prof. elm. He will give you the masterball.
use a masterball.
blablablablablablablabla
After you beat the game, it will become a roaming pokemon. It will run after the first turn, I suggest using the masterball or using a strong wobbufett. -CrystalManiac
Team Magma Hideout
You can only get one
In team aqua's hideout
from your enemy teams base
You find it in the team aqua hideout.