Well, you use this thing called hacking.
You can get 2 Master Balls in both versions.
you can trade a Pokemon from black or white holding a master ball.
The normal 1 from Professor Juniper in Mistralton.
You can get multiple Master Balls in Pokémon Black 2, Professor Juniper will give you one once you run into her in Mistralton City and you will also receive one from Colress once you battle him and defeat him on the Plasma Frigate after you've beaten Iris, the Pokémon League Champion. Additionally you can win Master Balls from the Raffle Shop in the Join Avenue.
Its actually tornadurus on Pokemon black and i think you have to have either loads of ultra balls or a master ball cos thunderous and tornadurus are both hard hope i helped
You can get 2 Master Balls in both versions.
You don't.
In skyrim
you can't
you trade 100 times
hack the game
Ar code
you can trade a Pokemon from black or white holding a master ball.
the professor will give it to you after you have beaten the 8th gym.
action replay codes
u can only get one master ball in Pokemon Black to my knowledge, unless u trade with someone whose Pokemon is holding a master ball, or if u hack it, which there is no hack to.
in the pokemon league after beating the elite 4 talk to each 5 times them YOU HAVE TO BEAT THE CHAMPION WITHOUT LOOSING 1 POKEMON AND THEN GO TO THE BLACK CITY mart and you can buy master balls