Its all those tiny details I guess. It helps build more rounded characters and rids the sense of disbelief when they start talking about 'water spirits' and 'egg eaters'. Even in episode 21 there are tiny things are fun to catch. Like when Chagum touched his own face after Balsa recounts how she was scolded.

As always, this episode was packed full of explanations. How Balsa became part of a power struggle and her own desire for revenge. Though I would have liked to seen more of kid Balsa and Tanda, its nice to see how they first met.

BTW, I found out recently that this anime is based on a novel. Apparently the "Serei no Moribito" is just one book out of many. Here's to hoping a second season is in the works.