Pig brother doesn't give me the gold coin

[ShadowStorm]

I'm at the point where I've exhausted the dialog for the brother at the Tiger Temple (he's no longer there) and when I talk to the guy at the Rockrest Flat, he doesn't attack me. I've gone back-n-forth between each location 3+ times, I even restart the game.

Any ideas?

[樹皮]

The gold piece you need is dropped by the First Prince of Flowing Sands in the valley of despair. Defeat him and then go back to where the pig was, and you'll be set.