I've read many xianxias and this one is a soft spot for me, to the point I went to mtl to read it, but it's really not great from a critical perspective. Also, there's two stories, where the first ends at like chapter 3800 or so — the 2nd sucks.
The start, for me, is pretty boring. But it gets much better after ascending from the lower realm. There is a very unique plot after the middle of the development of the story which is what mainly makes me like this novel.
The harem isn't the best, there are only 3 relevant wives while the list is much bigger than that, and those that aren't relevant simply get abandoned — even though they get carried around. Although, those 3 wives get developed quite well and you either love or hate them.
The main problem of the novel for me is that aside from Ling Han, the characters have a personality that is too "forced". You will have someone who lived for trillions of years but still act like a mischievous child, for example.
Anyway, I still recommend