Question: what can you do after you beat pokemon emerald?
Answer:  Go to Battle Frontier and get the Gold Symbols.  Defeat Steven in Meteor Falls. |Steven's Pokémon| ...   Catch new Pokémon in the East section of the Safari Zone.  Battle Trainers on the S.S. Tidal.  Catch Groudon, Kyogre, and Rayquaza. |TIP| ...   Hunt down Latias or Latios.