Saffron, you have to beat Giovanni and the president of the place will give you a master ball for saving him and then you can beat the Saffron gym. That's how. :)
You don't get a Master Ball in Mauville City.
you get your first master ball after defeating Giovanni in safron city in the biggest building.
you cant really change balls that's not how it works you have to get the master ball from the president of the company that makes Pokemon products in saffron city. that's how you get the master ball.
You go to the Veilstone H.Q. in Veilstone City and go to Cyrus and defeat him and he will give you a master ball.
You don't really need a Master Ball to get a legendary. However, the only other way to get a Master Ball legitimately is by the Jubilife City lottery. If all of the numbers match, you get a Master Ball.
You don't. The only master ball that you get is from Cyrus after you beat him in the galactic HQ in veilstone city or drew a lottery ticket at Jubilife city and match all 5 numbers to get a master ball.
In the galactic HQ in veilstone city.
You should get the Master Ball by talking to the President of the Silph Co. in Safron City after you saved him by defeating Giovanni.
You can get a master ball in the hideout of team aqua in Liliycove city. I don't know the exact route, but the warp panels will teleport you to a place with 4 item balls, one of them is a master ball.
You first go to Silph Co. in Saffron City(the largest building in the city) and rescue the organization's owner guy from Team Rocket. Then he will give you the Master Ball.
Fly TO Lilicove city and Surf ontop and you will find a cave,go inside and find the master ball
You get it in The Team Aqua Hideout by Lilycove City.