Since starting a new game on the same cartridge erases the current game, does using a Key mean restarting your game, or does it mean that the Elite 4 will now be in Challenge mode, and you will continue your game?
I assume that if I wanted to battle the Gym Leaders in Challenge mode, I would have to begin from scratch.
Regarding the shiny charm, I don't need to have every Pokemon in the National dex in my possession, but I need to have caught every Pokemon once (excluding event Pokemon), am I correct? I know the PC will expand once 16 boxes are filled, but I don't really want to keep Pokemon that I won't use...