It hasn’t been updated in a while, so you might not want to read it for now.
I think it’s pretty decent. The harem isn’t some dramatic mess; it’s built up pretty casually. The plot is pretty interesting, and the mc’s powers are cool.
So far, I’d say it’s like Solo leveling + Three beautiful vamps, but a bit below them. I still like it, but I haven’t read all of it yet.
Overall, I’d give it about a 7/10, which is pretty much a 3.5/5.