If your looking for one I'll list 6: (content: Gang, angst)
1. Thug wife
2.For better or worse
3.to have to hold (pt.2 Of FBOW)
4. Love story of an ugly girl
5.For the grave
6. Before you hit the ground

Well, you said action and BTS so I just had to think of this classic: https://archiveofourown.org/works/5293532/chapters/12219563
It has lots of action but it also has so much more (there are few things this story doesn't include), this story just draws you into its world and seriously, it's a long story but it's ABSOLUTELY worth it. Every chapter.