Caterpie
in spear pillar of course
explosion 250 power
I heard it is shadow force.
The most powerful water type is Suicune.
Kyogre.
I know that there are 2 super rare ultra powerful Pokemon in the whole entire Pokemon world.Those Pokemon are Raquaza and Arceus, but what i know is that RAQUAZA is by far the most and i mean the most powerful ultra legendary in the entire Pokemon world.
Lugia Mewtwo Mew Deoxys On Diamond, Pearl and Platinum Arceus is the most powerful. You can only get it by using action replay.
The most powerful water type pokemons are kyogre and Palkia. Wrong. Palkia and Lugia tie for it. Kyogre is less powerful. But Arceus with the Water Plate could be considered more powerful.
The strongest Pokemon in Platinum is probably Arceus, to get Arceus, you need a mystery event, but that event is finished now. :( The second strongest Pokemon would probably have to be Giratina, or probably dialga or palkia.
Golden Arceus
You should use some powerful fire type Pokemon although i used various types one of which had a grass weakness which was empoleon, but by then i was the most powerful person in the game, so it might not be easy for you. Hope it helps.
i like Pokemon platinum the most