Question

What do I do after besting Tate and Liza?

Answer 1

Got to route 128

After you get the dive hm from steven, go to route 128 and dive down to find the seafloor cavern. Go inside and find your way through. at the end of the seafloor cavern you battle Maxie / Archie and they awaken Groudon / Kyogre.

The story will then continue from there.

Source
Source

Hope I helped

Comments

mr turtwig is absolutely right on the dot. btw if it is sapphire it will be kyogre and if it is ruby it will be groudon.