Download vba emulator (v 1.7.3 recommended)
Download Pokemon emerald (preferably) ROM (edit/update: you need 2 of these with different saved files
or characterS for the mixing records to work properly otherwise one secret base will overwrite another)
Complete at least 5 Pokemon emerald journeys at least until you defeat the Champion (Wallace)
Create at least 5 secret bases on each character that are near each other and preferably in sequence (bottom to below)
On the first 4 files train 5 minimum amount of Pokemon of different types (including a starter), without using legendaries, or pseudo-legends (ubers). They must be in the level 50's. Then on the 5th file do the same except have the main pokemon without a starter but with a strong pokemon. Use this list: http://pokemondb.net/pokedex/game/ruby-sapphire-emerald
Now you have the newly created "Pokemon Defiance Team"
Create a 6th file, your main file, defeat the elite four and champion (Wallace), heal. Mix records with all previous 5 files or other characters. Then defeat the Pokemon Defiance Team wherever you had made it. If you are able to do this you can stop your long journey or expand it.
Simple as that, your extended journey is completed.
[Links and downloads will be possibly posted at a later time].
[update: a possible video of this 1 instruction video and 1 game-play video will be posted at a later time]
Note: The mix record trainers will have a trainer (say bugcatcher/cooltrainer) before the name you had named
one of your character(s), since its defaulted. Therefore every character(s) name must be a short name
(presuming no more than 5 characters (AAAAA)
WARNING: Save the game before you duel these trainers (Pokemon Defiance Team) of the 5 trainers
b/c you may not be able to face them again once you have beat (any of) them or maybe lost to them
(Last Updated: 6/12/2016)