In this question the answer says that you need to get Regice, Regirock, Registeel from R/S/E and I don't have any of those games, so is there another way I could get those in Pokemon Diamond or is there any other way I could bring life to Regigigas ?
Well, except using Pal Park, you may trade. Otherwise, no.
There were events to get regigigas and the 3 regis for platnuim.in black2/white2 you can get registeel/regice.Other than pal park and trade sorry,nothing I know of
