Ground type Pokémon.
Steel. It's immune to Poison (takes NO damage), and many steel types can learn Earthquake to hit for high damage. Additional types, however, can make quite a difference, e.g. pull a Steelix against a Toxicroak and Toxicroak will smash it with Close Combat or most other strong Fighting moves.
Fighting-Type moves are weak against Poison-Types, Flying-Types, Psychic-Types, and Bug-Types. Fighting-Type Pokémon are weak against Flying-Types and Psychic-Types. My best guess would be leaf Pokemon but Ihavent played it in a while They are pretty effective against normal type Pokemon.
There are several types that work well against Rock-Types. Water and Grass are the most commonly used against them, but Fighting pokemon, Ice and Steel works as well.
Electric-Type moves are ineffective, they don't even do damage against Rock-type, or even Ground-Type pokemon. Fighting, Grass, and Water is best when fighting Rock or Ground types.
Koga uses primarily Poison-type Pokemon. Psychic Pokemon would be the best bet. Ground-type Pokemon would also work, but will not be as effective against his Venomoth or Crobat.
There is no "best" Pokemon to defeat the Elite Four. You can use any Pokemon you want, as long as they are strong enough to face them. If you want to strategize, Lorelei uses Ice Pokemon, so Fire, Electric, and Grass types would be useful against her. Bruno uses Rock and Fighting types, so Water, Psychic, and Fighting types would be useful against him. Agatha uses Ghost types, so Psychic, Ghost, Bug, and Poison, would be useful against her. Lance uses Dragon types, so Ice would be very useful against him. As for your rival, you'll need a combination, there isn't just one type to defeat him. Just use a combination of the above types.
Fighting-Type moves are weak against Poison-Types, Flying-Types, Psychic-Types, and Bug-Types. Fighting-Type Pokémon are weak against Flying-Types and Psychic-Types. My best guess would be leaf Pokemon but Ihavent played it in a while They are pretty effective against normal type Pokemon.
Lugia because it is physic and super affective against poison and fighting but don't use it against dark because they will kill it easily
Fighting type Pokemon
Fire types are the best against ice type pokemon, fighting types are another good chose.
Fighting and Ground type moves are super-effective against steel type pokemon.
There are several types that work well against Rock-Types. Water and Grass are the most commonly used against them, but Fighting pokemon, Ice and Steel works as well.
Electric-Type moves are ineffective, they don't even do damage against Rock-type, or even Ground-Type pokemon. Fighting, Grass, and Water is best when fighting Rock or Ground types.
Fighting and Ground type moves are most effective against dialga, since it is a dragon+steel type pokemon.
Take a mixed bag of Lvl50+ Pokemon.Water types work best and fighting and poison types would be screwed if you bring them out.
depends on Pokemon. against lorilei my zapdos deals to dewgong, cloyster and lapras but its my charizard that's good against the ice type.
Koga uses primarily Poison-type Pokemon. Psychic Pokemon would be the best bet. Ground-type Pokemon would also work, but will not be as effective against his Venomoth or Crobat.
There is no "best" Pokemon to defeat the Elite Four. You can use any Pokemon you want, as long as they are strong enough to face them. If you want to strategize, Lorelei uses Ice Pokemon, so Fire, Electric, and Grass types would be useful against her. Bruno uses Rock and Fighting types, so Water, Psychic, and Fighting types would be useful against him. Agatha uses Ghost types, so Psychic, Ghost, Bug, and Poison, would be useful against her. Lance uses Dragon types, so Ice would be very useful against him. As for your rival, you'll need a combination, there isn't just one type to defeat him. Just use a combination of the above types.