Xianxia is quintessentially a contrast of light and dark, good and bad, gods and demons, and it is stylistically depicted by monochromatic character and color themes with slight differences in plotlines. If I'm being honest, this genre is my least favorite; notwithstanding, I have seen a couple that are slightly less ridiculous than most with my fave being Love Between Fairy and Devil (LBFAD) and my least fave being this tedious and pretentious Immortal Samasara.

Firstly, Yang Zi, the lead actress, is such a one-trick pony who seems content to play different variations of the same "dim and somewhat smart" character which she played not only in IS (Immortal Samsara) but also in Ashes of Love and Legend of the Dragon Pearl. If someone edits clips of her performances in these dramas, I bet you wouldn't know they were three different series.
And therein lies the problem not only with Yang Zi but also with Xianxia as a genre. It's too stylized with little to no room for maneuvering of plots or themes. There's the demons are bad and heavenly beings (HB) are good trope where the heavenly beings fight endlessly for dominance with a side plot of some HB prince who happens to fall in love with some lower HB twig or leaf spirit. Like clockwork, the writer never misses to give us the useless fairy with the baby voice (one of the worst aspects of LBFAD) who later comes into her power after being tossed around and abused by the higher HBs. Toss in a love quadrangle, some men in bad wigs, and the most watered-down set props which, given this is all CGI, seems like a wasted opportunity to liven up an otherwise bleary set of white clouds and grayscale.

Did I mention how much I hate the color and style? Sigh.

Anyway, IS is about a HB prince who falls for a flower; sadly, love is forbidden in heaven and they have to go through three different time periods of heartbreaks and forgotten memories whilst fighting some obscure bad guys who did some bad things. That's all.