I loved the story that has a lot of unique aspects. I loved the way they depicted gods and the graduation of powers down to basic humans. I loved the fact that everyone is depicted with flaws, even gods. I loved how complicated it was from the beginning to the end, while watching it I remembered the first scenes and thought "so many things happened and now the story is completely different". but some development took a little too much time.

when to watch: if you have a lot of time ahead, you wont regret it. it's very long so manage your time so you won't miss your sleep time.
audience: I think it could be better to watch after some maturation. there is also some violence so I'd say not under 18; and if you do some cultivation, it'll be interesting to watch again after you mature on your 40's. life and death matters are easier to understand when you have encounter it in your own life.