In the Aqua Hideout you should find a room with 4 items on the floor. Two are level 30 electrode's and the other items are an ultra ball and one of the 2 master balls. As with all Pokemon games, you can get the other master ball at the Pokemon lotto corner in lilycove department store.
you have to clone that Pokemon holding a master ball
a master ball!!!
You can copy a master ball on Pokemon Emerald by having one of your friends that has one sign on to their ds and connect the two. Then they can give it to you in the Pokemon center.
You can't get another master ball in emerald because there's no one will give you the master ball just the general will give you that.
capture legendary Pokemon like rayquaza.
No.
You can't do that unless you have emerald. then you can clone the master ball.
first you get amaster ball give the master ball to Pokemon copy that Pokemon over and over again then take the master balls from the Pokemon
you can get a master ball in the team aqua hideout. Its in a room with four poke-balls.
you can use master ball in caught the groudon
Clone your Pokemon and give them the master ball
With an ultra ball or master ball in sky tower. The name of it is Rayquaza :)