Quote from: Jelly Soup on May 19, 2010, 07:25:49 PMi think what elite is asking is if you can download it through mystery gift on hg/ss, and that is a yes since i tested it on my soulsilver
All Arceus work the HG/SS event, even hacked ones (this also goes for Jirachi). This has been tested online by various people, I think documentation can be found on Bulbapedia.