
Here's a few historical unpopular bls:
1. Shadow crown >shounen ai, sh*tty seme
2. Silent lover >shounen ai, sh*tty seme
3. To be or not to be >shounen ai, isekai
4. Two souls >shounen ai, body swap
5. Gongmul >yaoi, sh*tty seme, mpreg
6. 2ha/ Dumb Husky and his White Cat Shizun >this one's pretty famous but couldn't help recommending it!
7. The Emperor Is A Gay >shounen ai, harem
8. Tale of the Yellow Dragon >this one's pretty famous too but its too good, had to recommendate it in case you haven't read it yet
9. Conrad-YA Edition >shounen ai, older uke and younger seme, fantasy, dragons
10. Soul Contract >very underrated shounen ai, definitely give it a read, it's superb!

Also here's a list with unique plot mangas/manhuas https://www.mangago.zone/home/mangalist/1149533/
I read anything but mostly historical manga/manhua/manhwa or BL.. pls recommend stuff for me to read that dont have an overused plot or storyline