Not a lot of Murim BLs out there to be honest...
https://www.mangago.zone/read-manga/midnight_dweller/
https://www.mangago.zone/read-manga/flowers_find_a_way_to_bloom/
https://www.mangago.zone/read-manga/only_when_heavenly_demon_losses_his_virginity_will_murim_survice/
https://www.mangago.zone/read-manga/tread_lightly_on_thawing_ice/
https://www.mangago.zone/read-manga/raising_the_demonic_cult_s_leader_shounen_ai/
https://www.mangago.zone/read-manga/dangeum_and_jigyo/
https://www.mangago.zone/read-manga/murim_s_possession/
https://www.mangago.zone/read-manga/the_demon_leader_s_lover/
https://www.mangago.zone/read-manga/celestial/
Well.. That's all I could dig up from my list in Korean Manhwa BLs
https://www.mangago.zone/home/mangalist/2749972/
Can check Manhua Historical List maybe for Cultivation ones?
https://www.mangago.zone/home/mangalist/2739365/
Or just Murim themed Lists of webtoons in general
https://www.mangago.zone/home/mangalist/2097563/
Happy Reading!
(๑•ㅂ•)و✧
Anyone know good murim Bl? I've read Bad Friend and Demon Leader's Lover