O K2 (2016)

Both Dramas ML are top elite agent in their field (TV - NIS agent , K2 - Soldier)
Due to some reasons ML gets rogue/disappeared due to conspiracy
Full of Action, Mystery, Thriller which will keep you on the edge to watch what happens next
If you like the veil I suggest to watch The K2 as well

In both kdramas the theme is used: Money is power.
Both deal with corruption and murder. Somehow Signal ended for me where the story of The K2 might start.
2 of the best kdramas that got released in 2016
definitely a must watch!

Both are action dramas that also involve romance, and both male leads help, save or rescue the female lead.