help

It's much better in my opinion and for mature minds it's called "the beast must die "

Warehouse

Anything by Harada tbh but here: https://www.mangago.zone/read-manga/color_recipe/

https://www.mangago.zone/read-manga/nii_chan_harada/

https://www.mangago.zone/read-manga/criminal_interview/

https://www.mangago.zone/read-manga/blind_play/ (I have a link where you can read this)

https://www.mangago.zone/read-manga/interview_with_a_murderer/

https://www.mangago.zone/read-manga/ten_count/

https://www.mangago.zone/read-manga/obey_me/

https://www.mangago.zone/read-manga/black_mirror/

https://www.mangago.zone/read-manga/adam_no_rokkotsu/

https://www.mangago.zone/read-manga/the_world_of_pieces/

https://www.mangago.zone/read-manga/stalker_s_game/

https://www.mangago.zone/read-manga/itou_san_kuraka_sui/

https://www.mangago.zone/read-manga/save_me/ (Not BL but I highly recommend this)

Some of those aren’t like Sangwoo’s and Yoonbums relationship. Stalkerxkiller, it’s more psychological stuff.

yup ^^^ what mangalover said. Harada is no. 1 go-to for twisted stuff.
The other twisted author that's good at the theme is:
Nishin Masumi
> https://www.mangago.zone/r/l_search/?name=nishin%20masumi
(the overall trend of their works is basically gore, rape and plot twists)

Some miscellaneous mangas but still amazing ash:
psychopath x sociopath
> https://www.mangago.zone/read-manga/interview_with_a_murderer/

necrophiliac x zombie
> https://www.mangago.zone/read-manga/individual_diet_preference/

psychopath x demon
> https://www.mangago.zone/read-manga/madk/

Chew and swallow
Rent boy

I see Harada mentioned but I think you should also try Ogawa Chise also try Caste Heaven by Ogawa Chise also (sorry if I spelt anything wrong)

Pscho( young dream) , obey me, warehouse, escape into oblivion, black, mirror , moritat

Cellfish too. Enjoy