Azii

https://www.mangago.zone/read-manga/love_supremacy_zone/

Hey! I'm not sure if these will suit your taste but I personally love most of these [BL stories] - not all of them fit really well tho, I know exactly what type of story you're looking for but couldn't find the perfect fitting ones (even though there definetly are some!!) Hope you still enjoy :P
https://www.mangago.zone/read-manga/dawn_of_the_dragon/
(reincarnation - modern world)
https://www.mangago.zone/read-manga/the_secret_of_the_depths/
(replacement/reincarnation)
https://www.mangago.zone/read-manga/tale_of_the_yellow_dragon/
(other world/historical/mythical)
https://www.mangago.zone/read-manga/eyes_clouded_by_the_tiger/
(reincarnation in side story)
https://www.mangago.zone/read-manga/foul_s_start/
(idk, kinda reincarnation?)
https://www.mangago.zone/read-manga/possessed_by_a_cotton_ball/
(other world)
https://www.mangago.zone/read-manga/dreadful_night/
(time-loop)
https://www.mangago.zone/read-manga/heat_and_love/
(mythical)
https://www.mangago.zone/read-manga/piercing_stab/
(not yet, but reincarnation)
https://www.mangago.zone/read-manga/geolson_s_past/
(reincarnation - modern world)

oh btw these are mostly focused on romamce I lowkey didn't read your caption bruhh lmaoo

https://www.mangago.zone/read-manga/kyou_kara_maoh/

No, its totally okay because I love these type bls too like IVE BEEN looking for recs in bls with these tropes, thank you so much. Even if you didn't give me the recs in the question, you gave me ones I also wanted ヾ(☆▽☆)

yayy I'm so gladd! it was really fun to pick these out of my list so if you ever have sth else you're looking for, feel free to message me! have fun (*≧∀≦)