Whenever I scrape through the action genre, it's usually power fantasies and such, there isn't anything wrong with that, just that it isn't my choice of edible. It's usually tagged by 'Strong to Weak', making me wonder about the opposite result. Looking for suggestion go read. Stuff I think it would fall under but not necessarily restricted by: Characters settling down from a life of hardship Lose of Power Losing something bigger to gain something smaller that they value Etc... Please not that it can also be of personal suggestion of a book you think can possibly fall under the requested.
Thats a very tough topic. I think most people will not be interested in reading those of novels. The only thing that comes to mind right away is the kind where the weak mc is protected by strong side chars or the mc is misunderstood as strong.
The Strongest Wizard Becomes a Countryside Guardsman After Taking an Arrow to the Knee Havent redt this one but the title comes to mind reading the post.
How about ordinary common JP harem, mc at one point having a lot of not-touched harem members (power level 3+) however in the end it becomes OTP ending (power level 1) or open ending (power level 0). From many heroines to become only 1 or none at all, isn't that we call true downgrade
Tbh there are a lot of strong to weak novels. Most regression and rebirth novels are like that. However, mcs will eventually get stronger. So, strong to weak to strong. How to Live as the Enemy Prince - mc regress and posses a sick prince’s body after he was a knight. Beware that the author passed away before completing the novel (there are around 400 chs). I am the Monarch - mc regresses to his younger self Reverend Insanity - no need to introduce this one