Arceus
NO. Only ash got that as a choice. You have to catch it in the viridian forest, but it's rare
cheat codes for powerful pokemons at starting point of the game diamond and pearl
the most powerful Pokemon is the alpha Pokemon arcues this is debatable since different Pokemon have different stats, even with the same kind, also the moves used and strategy by Pokemon/trainer have a lot to do with it, but arceus is widely considered the best, it is only available by cheats or events, not in the game.
Arceus
Caterpie
Arceus is the most powerful, with a base stat total of 720, the current highest. sds ooo
The most powerful water type is Suicune.
dragonite
mewtwo
Mew
The strongest (most powerful) Pokemon is of course rayquaza.
Kyogre.