Review Detail of Rensarian in As An Immortal, I Only Learn Forbidden Skills

I've read the first forty chapters, and so far it seems to be pretty good, much better characters and more believable interactions than most other novels. I saw other reviews say that the pace is slower than others, but I disagree. The story moves pretty fast actually, it's just that his personal strength doesn't improve as fast in comparison. To me, that's a good thing, but maybe it isn't to others.