I checked your profile to see if you’d watched what I wanted to recommend, but these are the ones that came to mind right away. I couldn’t think of many Kdramas, but Cdramas have a lot of god/demon themes. I arranged them in the order I thought you might find most to least interesting. If you need more recommendations, lmk
c-dramas
Love between Fairy and Devil (2022)
When Destiny Brings the Demon (2025)
Till the End of the Moon (2023)
Eternal Love (2017)
Ashes of Love (2018)
kdramas
Guardian: The Lonely and Great God (2016)
Tale of the Nine-Tailed (2020)
My Roommate Is a Gumiho (2021)
My Love from the Star (2013)
Doom at Your Service (2021)
The Bride of Habaek (2017)
Celebrity 
