Looking for missing Pokemon Platinum Darkrai Event Video!

Unfortunately I can’t help you find the video but I can give you some more information on why it vanished, back sometime around the early 2010’s I believe, there were some pretty infamous trolls who were striking his videos down for nefarious purposes and this wasn’t just happening to him it also happened to some other big youtubers at the time such as NitendoCapriSun and Chuggaconroy for example, unfortunately his YouTube was deleted after he received enough false copyright strikes and as a result most of his content from around that time was lost including the video your looking for. That being said Marriland himself probably doesn’t have the videos themselves anymore and it’s very unlikely it can be uploaded by him especially since he really doesn’t use YouTube these days or that it was saved since I don’t think a lot of people got to do that, I do wish you luck on your search though and that it can be found in some way! 

web.archive.org/web/20090809232529/http://www.youtube.com/user/Marriland

Is the video titled "Darkrai Member Card Wi-Fi Event!" the one you're looking for? Unfortunately, I don't think it was archived with the exception of the thumbnail/title.