what u do is find diagla in mt. cornet then you go to sunyshore city. then what u do is get waterfall then swim all the way to the Pokemon league. next u beat ur cousin then u go to the person blocking the door talk to them.they will let u in , beat the elitie four (which is really easy to do) thenu beat the Pokemon leaguer (which is Cynthia the girl u met in eterna city), after that u beat the Pokemon league
-mongmong908
You can find out how many times you have beaten the Elite Four in Pokemon Diamond by checking your PC in the game.
You have to trade them from older versions of Pokemon.
it is the elite four
nation pokedex
The champion in the Elite Four.
defeat the elite four
Random.
the same
in Pokemon diamond it is in were the elitle four thing is outside in the water. and that route after it were shaymin is. but you have to use a rod.
The Pokemon leag (derrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr) The Pokemon leag (derrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr)
In the Pokemon games, the Elite Four are kind of the final boss to the games. In every game (including Pokemon Diamond) you will find them at the end of Victory Road.