I am now in Gifu Castle/Demon Caves and whenever I try to enter the demon caves there is a stone man blocking my way. I do not know where else to go from here so do I have to do something to turn him back or something? thanks

I have the same problem. What do I do to get past the Stone guy blocking the cave?

Ya, you have to go through the caves first and obtain the great powder tube, which turns people back after they are fossilized. You might already have it if you did the caves first - you have to select it from the items every time you want to use it.
If you dont have the powder tube yet, you have to go around the entire cave. I know that its easy to miss the entrance of the cave after warping there through the light path, so make sure you explore the whole area!
Hope this helps