you don't need either but its easier to have rotom so you can get the rotom forms faster.
The Trophy Garden is the only place to get Ditto in Pokemon Platinum, without trading or cheating of course.
yes as long as you can get to the uostairs part of the Pokemon center
In Diamond/Pearl/Platinum you have to get the national dex before you can enter the pal park.
The rare Pokemon which you can get before the Elite Four in Pokemon Platinum are Giratina, Mesprit, Uxie, and Azelf.
Absol is the Pokemon before Giratina. Absol's number in the pokedex is 209 and Giratina's number is 210. This is the one in the Pokemon platinum POKEDEX.
no.
rotom(legendary)
no but you must have the national dex on platinum
210 some are really hard
478 is the Pokemon froslass which is right before rotom on the national pokedex. and 485 is the Pokemon heatran which is right after palkia on the national pokedex.
The Trophy Garden is the only place to get Ditto in Pokemon Platinum, without trading or cheating of course.
yes as long as you can get to the uostairs part of the Pokemon center
Battle before the national dex - 52 Battle after the national dex - 68
yes since the sinnoh dex has evee in it
It depends. Before National Dex: 210 After National Dex: 493 With Glitch Pokemon: about 500
In Diamond/Pearl/Platinum you have to get the national dex before you can enter the pal park.
Im not positive that you can get rotom before the national pokedex but in the old chateau. In one of the rooms he is in the TV