https://www.mangago.zone/read-manga/brutal_satsujin_kansatsukan_no_kokuhaku/ ( I think most of us have read this?)
https://www.mangago.zone/read-manga/smiley/ ( I like this one)
BL
https://www.mangago.zone/read-manga/towards_the_darkness/
https://www.mangago.zone/read-manga/samenai_yume/
https://www.mangago.zone/read-manga/uruwashiki_shuen/
https://www.mangago.zone/read-manga/host_in_down/
https://www.mangago.zone/read-manga/heartless/
NON-BL
https://www.mangago.zone/read-manga/smile_it_s_just_a_dream/
https://www.mangago.zone/read-manga/torso_no_bokura/ (only a few of the stories are horror)
https://www.mangago.zone/read-manga/mienai_hito_tachi/
https://www.mangago.zone/read-manga/monkey_mountain/
https://www.mangago.zone/read-manga/ikite_kurete_arigatou/
recommend me one shot horror/gore mangas