the best Pokemon for the 1st elite four in Pokemon diamond would be a fire type with strong fire moves like flamethrower and fire blast because the first elite four is a bug trainer . i would personally recommend a rapidash or infernape.
Use an Arceus. If you can't get one, use Pokemon that are lvl. 85+. That will get you straight through. One more thing, each one of the four has a speciality (dragon, bug, psychic, and fire if I remember correctly) so get their weaknesses.
Empoleon -
Drill Peck
Surf
Waterfall
Brine
Staraptor -
Close Combat
Aerial Ace
Brave Bird
Fly
Abomasnow -
Blizzard
Sheer Cold
Wood Hammer
Rock Climb
Roserade -
Sludge Bomb
Cut
Giga Drain
Petal Dance
Drapion -
Crunch
Poison Fang
Rock Smash
Cross Poison
Steelix -
Iron Tail
Strength
Stone Edge
Crunch
I'll tell you one thing, I beat the Elite Four without restarting the game and the Champion by just restarting once with this team, so you can count on me. I don't give my Pokemon any hold items, that's my way. But if you want to give them hold items, you're welcome to, of course.
You can not teach Drapion HM06 Rock Smash, its just because I teach my HMs to my active Pokemon. The Brine move at Empoleon may be weak with 60 damage, but I like it because it'll deal 120 damage when the foe has half or less HP left.
In Pokemon yellow, I beat the elite four with:
Pikachu lvl. 51; moves=thunder, thunderbolt, thunder wave, (any powerful normal move)
Articuno lvl. 52; moves=ice beam, blizzard, sky attack, (a move that inflicts a status problem)
Kadabra lvl. 33; moves=psychic, psybeam, confusion, ( powerful normal type move, such as double edge or mega kick/punch)
Snorlax lvl. 33; surf, strength, rest, focus punch
Haunter lvl. 33; hypnosis, dream eater, (powerfuldark type move, i don't know one, but all i can think of is thief), sludge bomb
Charizard lvl. 43; Fire blast, ember, cut, fly
sorry i forgot what some of the moves were but i know some so i filled in the space with a recommended move
i had to save before each of the elites before i battled them just incase i lose to any one of them. Agatha gave me the most trouble, because of hypnosis, so bring like 5-10 awakenings.
the items i used were like 15 lemonades, 10 revives, and 10 awakenings
for loreli, put pikachu in your first slot. use pikachu mainly, except for lapras, who is a bit trickier, so try using kadabra's or articuno's most powerful move.
For Bruno, put articuno in your first slot. use charizard and articuno, because of their flying type, but don't use snorlax other than his onixes where you should use surf, as the onixes rock type is good against ice, fire, and flying, otherwise, snlorax will get schooled, even though he has massive hp
for agatha, (the most difficult in my opinion) put haunter in your first slot. use haunters hypnosis and dream eater, also use his dark type move which is super effective. normal type moves just wont work here so avoid them. her last gengar just downright pisses me off, and will eat through your Pokemon using hypnosis and dream eater, so use your awakenings and all your Pokemon, keeping snorlax for last as his tankish abilities will give you time to stall and revive/heal your other Pokemon
For lance, put pikachu in your first slot to obliterate his garydos and then switch to articuno, and use blizzard which is super effective against dragon. for his aerodactyl, use snorlax's surf.
for your champion rival, heal all your Pokemon to full health, and because you have no idea what to expect, put snorlax up first. for his sandslash use charizard's fly. for his alakazam, use either your kadabra or haunters dark move, but do note that both psychics do critical hits to each other. for his exeggutor, use charizards fire moves. for the water Pokemon he has, use pikachu, the fire Pokemon he chooses, snorlax surf, and for the electric, use anything other than charizard or articuno.
*note; evolve haunter and kadabra if you have the option to do so
*also, level up the Pokemon even more to make things al little bit easier
* you can swap out charizard if you don't want it as long as you have another fire Pokemon and teach articuno fly
The Elite Fours Pokemon are all in their 50s. The Champion at the end of the Elite Four has 60s though.
The first thing you have to be sure of is that you have beaten the Elite Four. Do that first!
To get the second Elite Four, you must have already defeated the Elite Four the first time, and the second time you go to fight them, they will all be leveled up, and become the 'Second Elite Four'.
You can find out how many times you have beaten the Elite Four in Pokemon Diamond by checking your PC in the game.
fourth of the elite four
Its best if you have 1 fire Pokemon and 1 ground Pokemon.
First Elite Four member is Aaron, who uses Bug Type. The first Pokemon he uses is Dustox.
yes swarpert is a greatest Pokemon to defeat elite four
Fire and water are the best combination to beat the elite 4.
Have a good Fire and/or Ground Type...
I would suggest fighting the elite four with a water, fire, ice, rock, electric, and fighting type pokemon.
Wailord
red or the elite four if you beat red the elite four Pokemon will be jacked up or red again after you beat the elite four his Pokemon are the same levels as before
The Elite Fours Pokemon are all in their 50s. The Champion at the end of the Elite Four has 60s though.
It surrounds the Elite Four, you can only go there after you beat the Elite Four the first time.
The elite four
battle the elite four