Forgive me if there any mistakes in the review, I'm typing this out on my phone.
It appears that the author does not accept constructive criticism?
I read until chapter 20; while many others only read a few chapters before reviewing, so I hope you do not attack me for reading only '20' chapters when reviewing.
The grammar is subpar, to say the least, but the flow of the story is somewhat understandable and I can vaguely comprehend the general direction of the plot. Furthermore, the characters are like cut out cardboard figures with no real personality; it appears that they exist only to push the plot forward. Writing about a 'billion-year old master' is difficult, to say the least, when reading you somewhat expect for the MC to know of a limitless abundance of skills yet this not shown very well.
Are we supposed to expect for the MC to have only been sleeping for most of those years? To even try to believe that is extremely unrealistic and requires a very broad mind from the readers.
For a person who is writing to make money, the quality is honestly not high enough. I've read many other originals on the site which have far less publicity than this, yet those stories have a more defined plot and much better grammar/flow.
So, I'll try to give my review according to the general system of WN.
Writing Quality: 2.5, although the writing/grammar leaves something to be desired; it is somewhat understandable.
Stability Of Updates: 5, the updates have been punctual as far as I can see. (Although I'm not sure if the quality has dropped over time as I stopped at C20.)
Character Design: This is honestly a 1-1.5 for me, the idea of a 'billion-year-old' master is extremely badly portrayed. My personal feedback is this: Don't bite off more than you can chew, for your type of novel, the MC being designed as a legendary 50-100-year-old genius that once reached the peak would have been much better. Why? This leaves room for error, as it is extremely unbelievable for a billion-year-old monster to know such limited information. Furthermore, the way the MC acts is far too unbefitting of someone that ancient. But if the MC was only 50-100 years old which is still considered an elder in human terms, it allows us to actually have leeway in our mind to believe that the MC is human and can make mistakes; even though he was at the VERY PEAK of the ENTIRE universe in his last life. The side characters that I've seen up to C20 are also extremely plain, they exist solely for the readers to have a 'funny' and 'unreasonable' read when one is drunk and not thinking straight. This is fine for some, but not for me.
Story Development: As I've said before, extremely plain where the chapters are spewed out only to be 'there' yet with no essential plot or meaning. 2-2.5.
World Background: Although it's not fantastic, there is still a vague world I can picture while reading up to C20. - 2/5
Overall, this novel was extremely dull and boring to me which disappointed me greatly due to the number of 5-star-reviews, which made me feel a need to review this novel myself so as to balance it out. This novel's idea even though not crafted very well may appeal to some but not me. (I may have an higher expectation than your average reader which could be because I've been spoiled from the number of good novels — which naturally also includes originals, where the grammar is much better than this story and they also have very well-thought-out plot but have a lower rating/less popularity than this story.
This was just my 2 cents on this novel. (I primarily created this since the large number of 5-star reviews did not match the content I expected)