Antidote
The Art of Taming A Tiger
Dreaming of the Dokkaebi
^These satisfy both action and mystery
Mission save the hunter
The hunter wants to live quietly
Turning
^^These are more action with some mystery
grandmaster of demonic cultivation! it's a manhua but maybe you'd like it.
It's a mystery drama with some action https://www.mangago.me/read-manga/sangyang_the_wanderer/
for the first one there isnt much action but its kinda like a shounen anime
https://www.mangago.me/read-manga/count_tachibana/
https://www.mangago.me/read-manga/sangyang_the_wanderer/ (PEAKKK)
Any suggestion for a bl manhwa which have more action and mystery like it should bl couple but storyline main focus should be mystery and action