Pokémon Ruby and Sapphire Elite Four and Champion Help in Hoenn Region (Types/moves effective against them)
Defeating the Elite Four
Pokémon games are always the most difficult once you reach the Elite Four, no pokémon center between the battles, so you have to rely on potions, ethers, and revives to progress you through. You won't be getting all that far if you choose the right pokémon though, so read this and make sure you get the right party for defeating the Hoenn Region's Elite Four.
Elite Four Sidney
Sidney is the First Member of the Elite Four and has dark type pokémon.
A level 46 Mightyena (dark type), a level 48 Shiftry (grass dark type), a level 46 Cacturne (grass dark type), a level 48 Sharpedo (water dark type), and a level 49 Absol (dark type).
Use fighting and bug types to win against Sidney. Fighting against everyone but Absol and Shiftry and bug against Shiftry and Cacturne. Fire also works well aginst Cacturne and Shiftry if you don't have a bug type. Don't use psychic moves or pokémon unless you absolutely have to, they will be defeated easily and quickly.
Elite Four Phoebe
Phoebe is the second member of the Elite Four and handles Ghost type pokémon.
A level 48 Dusclops (ghost type), two level 49 Banettes (ghost type), a level 50 Sableye (dark ghost type), and a level 51 Dusclops (ghost type). WIth the right moves you can easily defeat Phoebe and will be halfway through the Elite Four.
Use ghost and dark type moves in this battle. No Ghost, normal, or fighting pokémon. If you don't have a pokémon who knows ghost or dark moves, try steel type pokémon for a defensive approach.
Elite Four Glacia
Glacia is the third member of the Elite Four so if you made it this far, congrats you are halfway done. She has ice type pokémon so prepare accordingly.
Her level 50 Glalie (ice type), level 50 Sealeo (ice water type), level 52 Sealeo (ice water type), level 52 Glalie (ice type), and level 53 Walrein (ice water type) are all easily defeated with the right moves.
Luckily they are only two evolutionary chains and she has two Glalie and two Sealeo so if you beat one the other should fall with the same move (or almost depending on level differences). Use fighting and electric moves against Glacia to score the most damage. If a pokémon of yours has thick fat ability you will have extra protection against Glacia's moves.
Elite Four Drake
The last member of the Elite Four is Drake, and he uses Dragon pokémon. He is easily defeated as long as you follow simple rules that might be a bit difficult if you don't read carefully. Tricks and tips below.
He has a level 52 Shelgon (dragon type), a level 54 Altaria (Dragon flying type), two level 53 Flygon (ground dragon type), and a level 55 Salamence (dragon flying type). Dual types mostly so you can weasel if you know the right moves.
Dragon and ice moves are most effective, just don't use the same type pokémon. Dragon is super effective against dragon and his pokémon know moves super effective against ice types so just don't use them if you can avoid it.
Onto the Champion since you defeated the Elite Four, save and heal. Then continue.
Elite Four Champion Steven
The champion is the most difficult of the five so take your time preparing your party. He has steel and rock pokémon mostly but let's look closer.
He has a level 57 Skarmory (steel flying type), a level 55 Claydol (ground psychic type), a level 56 Aggron (steel rock type), a level 56 Cradily (rock grass type), a level 56 Armaldo (rock bug type), and a level 58 Metagross (steel psychic type). So many types so little time, defeat them all but how?
Fire, water, and fighting moves are what to use mostly but I will now go through each pokémon.
Skarmory is defeated with fire or electric moves.
Claydol is defeated with water or fighting moves, same with cradily, and armaldo.
Aggron is best fainted with ground or fighting moves.
Last against Metagross use fire moves.