It's a Chinese anime, these tend to start slow and explain or develop things towards the end. It's just how they write series, this time it's more annoying because the books are dark and they tried to push for more comedy. The novel is very good and the anime only compliments it with amazing animation, soundtrack and supporting cast.
Season 1 covers volume one of 4 or 6 depending on release. Stay away from this for a couple of years to make sure it's moving, there are multiple upcoming projects for this franchise and it's likely story releases will stall again as in ~2015 when the original series was discontinued (and quality dropped).