I don't think people really understand how big of a factor he plays into the games. He could be the key to understanding if these games are going to be one thing or another thing.

>Regigigas needs all 3 Regis present to fight him.
This either means the Regis are in BDSP, or we have to trade all 3 (or 5) from HOME to get them. Either way, this is a win-win situation because it either means we get Platinum content where we catch the Regis in BDSP, or we have a National Dex.