Any recommendation for some sad, dark, twisted, yaoi/shounen-ai, sex is not necessary and ...

This is a shounen Ai http://www.mangago.me/read-manga/zankoku_na_kami_ga_shihai_suru/

You could also read harada work if you haven't, they are really dark and have sex in it

http://www.mangago.me/read-manga/boys_next_door/
http://www.mangago.me/read-manga/jikan_akima_jinbutsu/
http://www.mangago.me/read-manga/haru_ni_kaeru/
http://www.mangago.me/read-manga/eien_no_aida_ni_miru_yume/
http://www.mangago.me/read-manga/bannin/

Thanks for your suggestion, Harada's manga's storyline is good

Thank you, I like the first oneヾ(❀╹◡╹)ﾉ~

(●'◡'●)ﾉ

well, killing stalking. But its a korean manhwa and i dont know if the art would meet your expectations but its really dark (๑•ㅂ•)و✧