What lvl Pokemon should I have for the Elite 4/Champion in Pokemon Diamond?

Question

I think I have a pretty good team but I'm not sure if I should go back and train or just battle the elite 4 until my Pokemon are tough enough to handle it. My Pokemon are:

Empoleon lvl 56: Moves:

Cut

Surf

Blizzard

Waterfall

Starapter lvl 50 Moves:

Aerial Ace

Fly

Quick Attack

Wing Attack

Azelf lvl 50 Moves:

Confusion

Uproar

Future Sight

Nasty Plot

Uxie lvl 50 Moves:

Confusion

Yawn

Future Sight

Iron Tail

Dialga lvl 50 Moves:

Flash Cannon

Rock Smash

Dragon Claw

Roar of Time

And Pelipper lvl 45 (used as decoy while I recover my Pokemon in battle) Moves:

Stockpile

Swallow

Spit Up

Fling

Tell me if you think I should train more or keep going because I am already at the 4th member of the Elite 4.

Answer 1

yo check this out your pokemon should be atleast lvl 65 by the time you even get to the elite four , but your pokemon have greeat move if you play right you sshould win

Answer 2

I had 2 level 100 pokemon and they got knocked out in the last battle. I suggest you get yours to level 60 and up then you should be good. I went in with level 40-50 and 2 level 100's and I won but it took me a couple of tries.

Answer 3

get your pokemons to level higher than 60 and you should do good..

Answer 4

Dialga