bxg or bxb, no harems, 18+
mostly fantasy isekai or xianxia yaoi featuring yandere lead(s)... honestly this whole list reads like the male yandere tag section LMFAO BYE

this is a list of books I HAVENT yet read/completed either because i haven't started them or because they're incomplete in translations, and actually a surprising amount of these books have a manhwa adaption if you read those (that's actually where I found most of these titles from). some of these are straight up tr*shy (but u didn't hear that from me)

on the other hand, here's a list of titles i've finished and enjoyed (I RECOMMEND THESE):
https://www.novelupdates.com/viewlist/60105/

This is part 1, since I capped the novel limit of 100 per list, lol.
Part 2: https://www.novelupdates.com/viewlist/61425/