Responses
Be it BL or straight I can only think of stories where BOTH the ml and mc remember a past life/regressed or only the mc, apart from this https://www.mangago.me/read-manga/beyond_memories/
make sure to read the spoilers first for these 2:
https://www.mangago.me/read-manga/royal_wedding_bamilssi/
https://www.mangago.me/read-manga/into_the_rose_garden/
And give me list of manhwa/manhua/manga where the ML is the one that regressed