This will only work if you have 2 games (fire red and emerald)/ game-boys with adapters.
Give the masterball to a high level (optional) Pokemon and trade it to emerald. In emerald go to the battle tower and put your Pokemon with the masterball in the PC and save.
Next take the masterball from the Pokemon (if its a high level Pokemon withdraw the Pokemon and item). Now go to the first woman at the desk and choose open level, select to eligible Pokemon. When she asks if you want to save hit yes and when you see "saving don't turn off" shut off your game.
Now turn it back on and don't worry when it says "corrupt file..." Go to your PC and see the Pokemon with the masterball then look in your party and see that same Pokemon with the masterball.
Then just trade back and you have one in each game and 2 masterballs.
No sorry you can't you have to have action replay to get more than 1 master ball anyway.
You can't
The only way to get more masterballs without cheating is to have other leafgreen versions or firered or ruby or sapphire or emerald or Pokemon colosseum or Pokemon xd gale of darkness trade the masterball that those games get to leafgreen other than that you have to win the lottery in ruby and sapphire and emerald at lilycove city to get another masterball then trade it to leafgreen.
You can trade with someone who has cheated. The likelihood is that if you get more than say 2, you have a cloned one or one obtained by cheating. Of course you can set up 8 raffle shops in join avenue and try win masterballs. though I haven't won one yet and I've played over 999 hours. Good luck with that
There's some kind of cheat for it, but I think the game is WAY more fun without them.
you can only get it by trading a machoke with Nintendo wifi connection
You can't get more masterballs because in the game they give you 1 master to catch that games legendary. (e.g) In Pokemon soul silver Professer Elm gives you one masterball to catch Lugia or any other Pokemon.
yes
you can't without cheating
You get a Masterball when you get a perfect in the lottory, but appart from that you are unable to get another one without starting again on a different game and trading it over.
Win the lottery at Jubilife city.
Action Replay (AR) you get 999 of them