Hmm.
So after I used the masterball I found in the Aqua hideout on Kyogre, the only other place to get one is to win the lottery in Lilycove.
Does that even happen? As soon as I made it to Lilycove... every single day, I've been taking a ticket, and it's never matched up. I've had this game for two years. (There was a period of time that I didn't play... about four or five months. Then I got the Prima's strategy guide, and started playing again.)
Also, what is this "action replay" I'm hearing about? I did a little bit of research, and it seems to me like a gameshark kinda thing.
If it is... then you've probably noticed I'm a little behind the times.