Train all your pokemon to lv 60,then save your game before you enter the elite four. The first elite four is sidney.he uses dual dark type pokemon. Use bug type,fighting type or any pokemon that can beat his pokemons other type. To beat the second elite four,phoebe,using dark type is the best. Using fighting or normal types will not inflict any damage to phoebe's pokemon. (note that ghost type will not inflict damage to normal types!) To beat glacia,the third elite four,use fighting type. (note that fire type pokemon will not work because glacia's pokemon is ice/water type.) To beat drake, the final elite four, use ice type or if you think you can beat drake's pokemon with one hit then use dragon type pokemon. To beat
the champion wallace, use electric type. Then,go for a cruise to the battle frontier and get ready to catch the legendary pokemons!