How do you beat the elite four on pokemon diamond?

Use good Pokemon

For the first Elite 4 member- Use Fire pokemon/ flying pokemon. All his pokemon are bugs.

Second elite 4 member- Use water pokemon. Two of this members pokemon aren't ground pokemon, so try a variety of pokemon on those two.

third elite 4 member- Water pokemon again.

fourth elite 4 member- Use ghost pokemon.

elite 4 champion- Since the champ uses a variety of Pokemon, I recommend to use all the pokemon used above, including a grass type.

~Snow

I have diamond. so i used my Dailga. i raised all his stats and raised his PP on Roar of Time and Dragon Claw.

He is teh one who got me through. but teh Champion has a pokemon called Spiritomb. it is a Ghost-Dark type with no weakness and it is rather powerful. have a strong flying type on hand. and use powerful moves such as fly. against her Gastrodon, make sure you have a high lvl electric or grass pokemon standing by. it uses Earthquake so grass is a better chouce.

She also has Rosade which is grass/poison and Lucario which is Steel/fighting. so either fire or flying moves will work perfect. as for her Garchomp use either ice or dragon moves, or even grass because it is a dragon/ground type.

her Milotic should fall to an electric or grass attack.

keep in mind her strongest is lvl 66 and her weakest is lvl 60.

hope that helps.

cheat

you get a better team, thats how.....