easy bring ultra balls($1200) and timer balls = easy first 30 turns use ultra ball and the rest turns use timer ball and should be easy
i have used the master ball = ="
something off topic: for kyogre if you just catch for pokedex i recommend you to use net ball instead of ultra ball it's cheaper and higher chance on kyogre (my record of using them on Kyogre, 1 ball, 3 ball and 8 ball catches)