Knowledge and curiosity seems to be quite a central theme, doesn't it? We get it with Gerald, who's considering it one of the most important things in life. Damien, who gets introduced already as driven by curiosity. Ciani, too. Zen, with a slightly more obsessed view. Narilka, to some extent. And as you say, the underlying theme of lost knowledge and the struggle to either regain it or replace it with something of equal value.

And when you think about it, the final enemy got beaten because Gerald and Damien sat down and figured it out - and it wasn't a magic weapon, it was, essentially, knowing about semantics.