Any movies you can recommend me that's  similar to "The Man from Nowhere " or at least has this sort of main character?

Basically a movie where the main character is hiding his identity or "skills"? 

or it can also be like the character underwent a process  ( maybe dieting, or learning how to fight or being really smart? ) and the people who knew him were shocked.

The only thing I can think of is Fly Daddy Fly (from out-of-shape middle-aged man to a fit boxer). And maybe Kung Fu Hustle (the change was brought upon him, though, not something that he actively did for himself).

Non necessarily/specifically skills for fighting only, just special skills?

  • Secretly Greatly - about a village idiot wjo is actually a spy
  • My Papparoti - based on a true story of a troubled youth who came to surprise and make people cry with his unexpected skills
  • Initial D - abput a dull and introvert highschooler who schools other drifters/racers
  • Rurounin Kenshin - a poor normal looking wandering samurai who is actually a legendary assassin from the past era
  • Beck - a bullied kid who finds his passion in music

✔️ Inside or Outside 

✔️ Memoirs of a Murderer 

✔️ Code Name Jackal 

I mainly know American movies 



✔️ Usual suspects 

✔️ Rain Man 

✔️ Beautiful Mind 

✔️ Catch Me if You Can