So we don't know what Bahamut is yet still. It could be a fish, a dragon, or a fish dragon. Maybe even something else entirely. Either way, this seems like the biggest thing he's going to grow so far, and it might be the most interesting as a result. Can't wait. I also faintly recall Sui was able to talk outside of her name, but they've focused so much on the once-sick princess that I barely remember anything about the rest of the cast. This is like the Namek arc of the series.
Also, it's been bugging me since they got to the desert, but that white lighting on the upper lips and lower eyelids of all the folks with darker skin is incredibly distracting. It's like they inverted the shading you'd expect in those spots, and it looks so distractingly bad.