Just finished playing the game and watched the trailer video again, but this time the symbols that the trailer shown being drawn on both Noloben and Taghira stuck out to me. I didn't use any part of either or those symbols in the game...Did they just concoct random parts of symbols being drawn to use for the trailer? Or is there supposed to be something more to it? Just wondering...

The trailer was made by UbiSoft, not by Cyan. The slate symbols used in the trailer don't correspond to those used in the actual game. Also note that Esher looks different.