I would like the drama or movie about a strong woman that knows martial arts or knows how to use a gun.. something like that. I've already watched King 2 Hearts. Know any good drama/movies that is similar in a way to King 2 Hearts? If you do please recommend!
My Wife Is A Gangster. Not great but kinda fits your criteria
Dramas

Myung Wol the Spy: almost the same as king 2 heart when it comes to south north and strong female lead and so on but the stories are deffrent.
Sweet Spy : Another strong female lead


Movies :

Duelist : strong female lead and it's the same lead actress from K2H plus the movie have the most outstanding male lead.
My girlfriend is an agent : Another strong female lead plus it's a funny movie, u would like it.
Spy Girl : Not as good as the other 2 movies but it still have a north korean in it that's good with guns.

I hope u enjoy them :)