I was planning on shiny hunting the legendary beasts in Soul Silver then whichever one I don't get I would hunt for in Heart Gold, but I wanted to hunt both of them AFTER I beat the game. However, no matter what I do, I can't challenge Morty in my copy of Heart Gold. I beat the rocket grunt in the Dance Theater but I still can't get in.
I've looked online and some say yes and some say no. I need to know for sure so I can be more prepared.