I did Thai boxing and BJJ for years, so I try to mix realism with fantasy for both the fight scenes and the training. The story is a little bit slower at the beginning though and then starts to pick up.
1. male protagonist
2. fantasy
3. very serious and imo interesting
4. no romance
5. weak to strong (he is skilled but everyone else is just too strong)
6. original
7. I have both blow for blow realistic scenes and general combat scenes
https://www.webnovel.com/book/the-sound-of-despair_19727115105063405