You still need to battle archie and max to let them realease kyogre and groudon using the orbs they stole but archie will be last cause he is near mosdeep and max is near lavaridge. so when you beat archie max will come and say that they are about to drown then steven wil show up and take you to sootopolis and see kyogre and groudon battling and you will be allowed to go to the origin cave to call wallace then ask you where raquaza is then you answer sky pillar then he will open the door and you will have to go up through a maze and talk to raquaza but you can't capture it already you can capture it after the scene when you go back to sootopolis
Source A Forum