You can have the national dex, but you can't complete it without transferring Pokemon from GBA games. Therefore, it's impossible to complete the national dex using only a DSi (without cheating with an Action Replay.)
impossible
No, it is impossible, but in the past Nintendo banned legendaries from being traded.
nintendo nintendo
Route 209 (after obtaining the National Pokedex, insert Pokemon LeafGreen into your Nintendo DS's Game Pak slot)
No!!! In Pokemon pearl diamond and platinum you can get eevees. pearl and diamond from bebe after obtaining national dex and platinum by bebe no national dex required.
Route 228 (after you get the National Pokedex, insert a Pokemon Leafgreen cartridge into the Nintendo DS's GBA cartridge slot)
go to Google then type in Pokemon platinum
Nintendo DS
NO, that is impossible. You need to trade and migrate Pokemon to complete the national dex.
Pokemon platinum
Pokemon battle revolution. Pokemon Battle revolution is a game 3D for Nintendo Wii, Pokémon Platinum is a remake of Pokemon DP for Nintendo DS
This is Impossible.