You have to use an Action Replay, there is no way to obtain more than one Master Ball per game.
in pacifollog
boiii
underwater in the tall grass but u have to search a while
by Nintendo events or by mixing records with someone that has one
First youll need to get the pokeball okie... then you open the ball or take out the pokemon and fukk it then it will get raped and so it will just leave.
you use a game shark code. here's the website where i got the code! http://www.supercheats.com/gameboyadvance/walkthroughs/pokemonruby-walkthrough06.txt
You can't catch Kyogre in Ruby... I would suggest trading or cheating. Unless you mean Murkrow, which you can't catch either. Again, the suggestions above.