There is a lot to say about this novel. Think the author don't have a lot of experience writing novel. So, I'm going to make it my job to comment as much as I can on the mistakes he makes.
The story: The story development is kind of too fast. 50 chapters in, and he seems like he's unbeatable. Also, what kind of bs is this when the mc asked for the mysterious orbs from the auction boss and the boss agreed just because the mc won the stare-down. Isn't the mc suppose to be grateful that he is saved by the boss?
Character design: The characters are fine, no problems with it. Just not that great enough to get a five star.
World Background: ...Seriously, author? So far, I have not seen any explanation about the levels and the power catalogs and stuff like that. There should be like, Level 1-10, regular human stats to Olympic champions stats. Level 20-30, surpass human limits. So on, so forth. After reading a lot of chapters, I didn't get any in depth information about the worlds and people's abilities.
Not trying to roast the author or criticize on no bases, just trying to give some constructive criticism to the author.