First off, it's kind of surprising to see that despite the good length of this story, it has attracted so little attention and this is its first review.
It should be said that if you're looking for depth in a story, sorry, but this is not that kind of story.
No, this story is instead made for readers who purely read for wish fulfillment and the satisfaction of an OP character - I'm not judging or trying to say those readers are less advanced.
For that purpose, this story is perfect. The protagonist, as all protagonists should, is able of skipping levels in battle. He's also cultivating a relatively slow-going but immensely potent skill, which is quite a common thing to see in stories like this.
The grammar is also very good for sites like this(I'm old school with comma usage, so the more sparsely-punctuated style like this throws me off a bit. Regardless, there are no real issues to be addressed) and outside of a few typos, which basically every story has, there was nothing I noticed.
The story's length bears a more in-depth addressing. Over 300 pages! That means that unlike some other stories on this site, readers won't be left hanging for a rather long time, a positive quality in a story.
All in all, if you enjoy reading about overpowered main characters with a lot of otherworldly experience, this story is perfect.
P.S. There are a lot of time skips here, and the author focuses more on the actual power gained more than the method the MC used to gain it. This becomes apparent early on, and somewhat annoyed me.