Question: what to do after mossdeep city?
Answer: re: After Mossdeep Gym... Go to Stootapolis City so you can just fly there after you Beat Archie and Awaken Kyogre. I would choose option 2 because it's a lot faster. Stootapolis city is in Route 126 Just you need Surf and Dive. The Seafloor Cavern is on Route 128 and you need surf and dive.