Paljae, Child of Winter. It's a manhwa and it's historical and has korean mythological stuff, heavens, humans, ascendants, demons. It kinda has danmei type of plot but it's Korean.
Summary:
It's more than just coincidence.
Young Paljae drifts to the isle at world's end to be taken in by Munryeong, a hermit with a mysterious past. But when Paljae begins to waste away in the sun-bathed climate, Munryeong takes his little companion on a journey to the cold north that uncovers their forgotten past encounter.
(It's my fav manhwa, it's honestly so well written and has amazing art, the characters and the story is complex and it's plot based)
https://www.mangago.me/read-manga/paljae/
I genuinely need new well written manhwa/hua action bls.. I felt like I've read everything.. Like seriously, can't Artists start drawing actually good bls instead of sa ones..