when you find that Pokemon if you have a master ball with you use a pokeball and you will capture it
You can't. You only get one without trading it from another Pokemon game.
Moltres, Zapdos, Articuno, Raikou/Suicune/Entei.
the masterball is for any Pokemon you want, it can catch them without fail ( it will ALLWAYS work ) . you are supposed to use it for mewtwo though. :P
weaken it and put it to sleep
Without cheats or any events they are Moltres Articuno Zapdos And Mewtwo
Use a masterball,parilize it,constently huck balls at it,damage it.
The only way to get an Articuno without GS is to trade one from Pokemon Red, Blue, or Yellow.
A fleeing legendary pokemon
you have to save your masterball no matter what and use it on mewtwo in order to catch it faster. otherwise, you are going to spend hours trying to catch it without any luck.
You cant - Articuno is a legendary and the only way to get it again is to start another game or cheat. When catching legendarys, always save just before you fight them, and if they faint, switch the power off without saving.
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.
EVERY Pokemon is able to b caught WITHOUT a masterball....... if you know a Pokemon will flee (latios/latias etc) have wobufett as your batteler so they cant escape.....Silph co.