Divergent Paths: The 3 Scenarios

The solution on the Ghost leaving the party came to me very quickly, and thanks to some great shorthand coding of the following events (There was no check for party membership for Shadow's remaining scenes, nor on Gau's for the Nikeah ferry. The game just listed both of them as "Party Character 2"), I mostly completed the 2 brothers' scenario tonight. I just need to figure out a quick, elegant way to prevent the character from accessing Barren Falls until the scenario is done.