I recently read book 2 & 3. I was intrigued by the daoist elements of the lore from the show which seemed fairly specific, and assumed the books would have more depth on this but it's more used as world building than anything else. The world is clearly inspired by daoism -- the fight of dark and light, the mentions of the taijitu symbol, the sword forms (directly drawn from tai chi sword), the five weaves of power match the five phases, the meditation the Void etc. The author def studied daoism closely. Overall i wasn't hooked but the books are pretty good.