Okay... I just went with Buck to that stone and he got it and walked away. Where should I go next? I also didnt find a legendary pokemon that is supposed to be in that mountain.

Also.. How do I get in the Snowpoint Temple?

And, at the end of the Victory Road Cave, there is a fat guy standing in front of a cave entrance not letting me pass.. Don't tell me what's in there, but do tell me when I can go in