Shay

https://www.mangago.me/read-manga/the_kagari_monster_family/

https://www.mangago.me/read-manga/i_became_the_husband_of_the_cult_leader_of_the_demonic_sect/

https://www.mangago.me/read-manga/k_9_keishichou_kouanbu_kouan_dai_9_ka_inou_taisaku_gakari/

https://www.mangago.me/read-manga/the_witch_and_the_mercenary/

https://www.mangago.me/read-manga/tenisaki_wa_kusushi_ga_sukunai_sekaideshita/

https://www.mangago.me/read-manga/oh_dangun/

https://www.mangago.me/read-manga/kamisama_gakuen_armeria/

I appreciate it gave me a whole bunch

White blood (so good i promise)
Crimson karma
Lv.99 Princess of Black Flame (pretty recent)
To a new life
SSS Class suicide hunter (best romance in an action manwha in my opinion)
Wind breaker (the webtoon, its not really action per se)
The Mafia nanny
Reminiscence Adonis
The Witch and the Mercenary
Golden man
Oh dangun (so cute)
Legend of the Northern Blade
S-Class Hunter Heals with Monsters (pretty new)
Academy Genius Swordmaster
Infinite Mage
Undercover chaebol high school
Team zero

Here hope it helps
https://www.mangago.me/home/mangalist/1704060/

Honesty hard to find much, but try these:
https://www.mangago.me/read-manga/ghost_window/

https://www.mangago.me/read-manga/trap_of_desire/

https://www.mangago.me/read-manga/hell_high_water/

https://www.mangago.me/read-manga/your_devotion_is_my_salvation/

https://www.mangago.me/read-manga/wolf_in_the_house/ Second couple’s story is more action genre

Red Candy, it has to do with spies undercover its so so good

https://www.mangago.me/read-manga/red_candy/