You can't sorry =(.
If you really want them back you will either have to cheat to get them or start the games again.
the best team for battle dome in Pokemon emerald is a grass type(against swampert , and a rock type(against charizard and salamance)
My Pokemon party is Charizard, Lapras, Dragonite, Aerodactyl, Snorlax, and Kingdra for the Leafgreen version. =)
Swampert. Swampert gets STAB, and also has higher attack than Charizard. Pupitar is just...poopitar compared to those two.
The best water Pokemon in Pokemon emerald I believe is Kyogre. kyogre is probably the stongest but i prefer a swampert if you don't like legenderies
Kyogre
Swampert or Wailord.
Level 36.
Train a mudkip to level 36.
You trade a Charizard of Pokemon leaf green version or firered version
Swampert's ultimate moves are endeavor, earthquake, hammer arm, and mud bomb
Sceptile is way better than Breloom. Swampert is better than Sharpedo, Swampert is also a Ground type.
Endeavor is a move that can be learned by certain pokemon like Swampert and so on.