Go to your house and talk to your mum and ask in the microphone can i have master balls.
don't listen
you can not get a master ball in Pokemon platinum only the one professor Rowan gives you
cheats
You can't.
cyrus gives it to you
no
Action replay
Yes there is a code for 999 master balls in Pokemon platinum
you have to have Pokemon platinum and a action replay then if u want just give your Pokemon master balls and trade them to games you want to have master balls
Pokemon lotery and action replay
Cyrus gives u one
Hacking
l and r