I remember the whole manhwa was in some kind of greyish yellowish colour where the seme is a demon and forms a contract with a human (uke) to keep an eye on him and they eventually fall in love. An angel is also behind uke. Both the seme and angel are looking for a sceptre. The uke is the ruler of monsters. I'm sorry if it's confusing.

I remember the whole manhwa was in some kind of greyish yellowish colour where the seme is a demon and forms a contract with a human (uke) to keep an eye on him and they eventually fall in love. An angel is also behind uke. Both the seme and angel are looking for a sceptre. The uke is the ruler of monsters. I'm sorry if it's confusing. The seme had shoulder length black hair, he later cuts them short.
i've read this before, plot twist after plot twist. so good to read back in days, too bad i also forgot the title. :(
Xamping that sounds so interestingly
Camping*
Same, I can remember almost everything but the title
girl..... https://www.mangago.me/read-manga/unbreakable_master/
Thank you so much, You're a saviour(つ✧ω✧)つ