This is not the worse fanfic that I have ever read, but it isn't great either. When I read the title I was curious. I was expecting a story about a kid in MHA with a cultivation style quirk, or at least a kid that frantically tries to cultivate to reach a level of strength that would allow him to deal with the coming conflict. Instead we get a character who sits in a pocket dimension (with auto farming capabilities), and cultivates for 100,000 years and becomes a completely untouchable god by chapter 4. Just like that, all the tension is gone, any and all problems that he might face are now nothing, he can just brute force any interaction and if anything blows up in his face he can just ignore the consequences. From that moment on, the story got quite boring and stale.
For most overpowered characters, they at least have some comedy to liven up the story, or some flaws that mean that the overpowered characters can't just brute force every issue. The closest this story has to comedy is peoples reaction to the MC's "stunningly handsome body," that causes so much disruption that he has to disguise himself, and very bland chinese cultivation story style face slapping. The face slapping is so bland that the characters, and the fathers that they call in after the whole "do you know who my father is" incident, don't even receive names. One of the great things of a good face slapping is getting to know how much of an a** the pre-face slapped character is. This takes a good while to set up well, character building for not just the main character, but also the villain. In this story, we know the boys who will be face slapped for a few pages, after which all we learn is that they are spoiled arrogant jerks. Combined with the complete lack of tension from how op the MC is, and the scene has little to no impact.
As previously mentioned, a good op character often has flaws or is funny or involved in comedic scenes or situations where their power is useless. Onepunchman is a great example of this, funny, has serious flaws in his personality (aside from his apathy, his personality is so "normal person" that he is actually weird when compared to the super quirky heroes). The MC has no flaws.
Writing quality: Fine, no major grammar flaws beyond the minor mistakes that are typical in fanfics. It does lack the "flow" that most good stories have in their writing.
Stability of updates: No complaints
Story Development: I have listed most of the issues that I have with the story above.
Character Design: The MC is a textbook bland Gary Stu, enough said.
World Background: Its MHA, but it doesn't feel like the background was made use of very much. Even has "there was once cultivation, but it died out" added into it, even though the world already has a power system: quirks.
