As he/she/it(?) is a hero you should use the "SPAWN_HERO" reward, remember that you need the hero company for that.
Does the dialog appear when you start the GC? Does it show the correct texts or vanilla ones?
You could try to implement you story plot file into another GC and test if it loads there. As I dont see the error, we should try to locate it.
If that doesnt work, I'll ask Jedi_Lu to take a look on this