In what way is that the theme? I don't get that from the story in the slightest. Just because they determine that one of the elements of creating a primal is willpower (belief) doesn't make the entire storyline "I gotta believe." It's such a tiny part of overall the plot that has instead been focusing on investigating the echo, learning how to kill Ascians permanently, and preparing for the Garlean's eventual return. If anything the theme is closer to "We're on the brink of war"especially considering the expansion coming up dealing with the Ishgardian war against the Dragons.