Probably either Spiritomb or Garchomp
arceus is i said party not single pokemon.
In Pokemon Diamond i say Torrterra is the strongest grass and ground Pokemon because i have a level 100 one and it's great.
You get a legendary pokemon, to level 100 (trade it).
At the very end of the tunnel is the legendary Pokemon Heatran. It is level 70, but is not the strongest of the legendaries. With an 8% catch rate you will need about 50-100 ultra balls to be sure of capture and some 60-90 level strong Pokemon. Good luck on capture and hope this helped!
I have a stoutland and its my favorite non legendary Pokemon but Reshiram and Zekrom both are the strongest Pokemon on black and white. This is the link to see the srongest and fastest ETC.
The strongest wild is heatran Lv.70,Garatina Lv.70,Regigagis Lv.70,and the strongest Acreus the god of all Pokemon at Lv.80.These are the strongest Wilds but they are all ledgendaries.
magikarp can be found up to lv 100 in the resort area
in the U.S.A? Nothing? there are no U.S events for diamond or pearl. Sorry. (In japan its the all legendarys event. You get all the legendary pokemon at level 100)
a Charizard level 100 Its actually a Feraligatr Level 100 Infernape Level 100 Missingno. (if you count it as a pokemon) Level 100 The Strongest Legendary is Arceus rapidash is the fastest non legendary and evolves from ponyta at lv 44 i believe but correct me if im wrong.
get all Pokemon you hav to lvl 100
It depends on the level, moves and nature of the pokemon. Mew Two is pretty good, and so is Zapdos, but a lvl 100 mew two would be more powerful than a lvl 20 zapdos.
u cant get lvl x Pokemon in Pokemon diamond those are only in cards but the highest lvl in Pokemon diamond is 100.