How to beat elite4 and champion in diamond?

Question

I have

graveler lv 46

roseraid lv 22

dialga lv 55

empoleon lv 60

chatot lv 12

Answer 1

I'd say just level them up more until you can do it.

Make sure you know the types of pokemon you will be fighting and prepare to use whatever pokemon is strongest against the one you are fighting and careful not to use one that is weak to that type.

Also have berries in their hand to eat if they get low health and have potions ready to use.

Check the chart below for Pokemon type, stengths and weakness.

By the way Pokemon isn't gambling.