This will be a 2 part review, reviewing this season as a standalone work and as an adaptation: This season essentially picks up right after season 2, it starts with Xiao Yan entering deeper into the desert in search of the Heavenly Flame and all the events after it up until his teacher falls asleep after he unleashes the Angry Buddha Flame Lotus for the first time. The plot is mostly understandable and flows relatively well. There is only one major problem in this season: they have the previous chapter recaps and some random narrated recaps. Like in EP6, they used the "narrated recap" to cutsome stuff out, which might throw some people off. Overall, the animation has more polish, especially the action scenes, but especially towards the end, there are some places where the speech (talking) unnecessarily cuts into the action/dramatic situation. It just feels off; time is of the essence, yet they are just talking without any movements, breaking the immersion and atmosphere. Overall though, it is a very well done season.

As an adaptation however, there are 2 big changes from what I can see. First, the reunion between Yun Yun and Xiao Yan was dramatized. I consider this a good change; it really up-plays the emotional moment and relationship between the two of them. 10/10 change (it was less dramatic in the novel, and no kiss), but the change at the end of the season felt awful. They made Mo Cheng into the final villain when he easily got clapped. Instead Xiao Yan fought a giant snake who was hired by the Heaven Snake Faction (or whatever). They probably changed the villain so Xiao Yan won't have enmity towards them later. I very much dislike this change and would have preferred the original plot.
Adaptation Score (how faithful to source): 7/10