Responses
there are no reincarnations involved but https://www.mangago.zone/read-manga/zettai_bl_ni_naru_sekai_vs_zettai_bl_ni_naritakunai_otoko/ this matches your description
beta
there are no reincarnations involved but https://www.mangago.zone/read-manga/zettai_bl_ni_naru_sekai_vs_zettai_bl_ni_naritakunai_otoko/ this matches your description
wanna read interesting ones where mc reincarnates into a story but is a mob/side character/watches main story from the sidelines please please rec me some