you can't
The professor
in team aquas hide out
There is only one masterball in sapphire and to get it you need to be through a lot of the game. The only place to get it is in team Aquas Hideout. Oh, there is one other place which is Lilycove Department store, where you can draw a lottery. Match all 5 numbers and you win a masterball.
from your enemy teams base
I am pretty sure you get a masterball.
In team aqua's hideout
you will find one in team aqua's hideout
probably action replay but you can just buy a firered leafgreen sapphire or ruby and just save the masterball you get from them and give them to one of your Pokemon and migrate it
You can trade masterballs from ruby, sapphire and emerald by winning first place in the lottery at the lilycove dept store but you need to trade with a lot of friends to do so.
You must either get a masterball from team aqua base or game corner. Then you must fight a legendary and throw the masterball right away.
give a Pokemon the masterball and put it in the daycare with a ditto then it will be cloned!!!!!!
u run into her in random places u well want to keep the masterball