have you read this? https://www.mangago.me/read-manga/never_understand/
personally don't like it, but it checks almost everything on your list.
This one’s rough, but so gripping and well-done: https://www.mangago.me/read-manga/geu_kkeute_issneun_geos/
Wait I think I can help you
Eighteen's Bed: https://www.mangago.me/read-manga/eighteen_s_bed/
Friend or Faux: https://www.mangago.me/read-manga/room_for_renewal/
Lost in the Cloud: https://www.mangago.me/read-manga/cloud_1/
The edge of ambiguity: https://www.mangago.me/read-manga/the_edge_of_ambiguity/
Yang Ilwoo and I(I can’t seem to find it a on mangogo so here’s another link): https://comix.to/title/2el1-yang-ilwoo-and-i
If You Hate Me So: https://www.mangago.me/read-manga/if_you_hate_me_that_much/
At the End of the Road: https://www.mangago.me/read-manga/geu_kkeute_issneun_geos/
A Shoulder to Cry On: https://www.mangago.me/read-manga/a_shoulder_to_cry_on/
Never Understand: https://www.mangago.me/read-manga/never_understand/
Form of Sympathy: https://www.mangago.me/read-manga/form_of_sympathy/
Here U Are: https://www.mangago.me/read-manga/here_u_are/
Kimi no yoru ni fureru(It’s not what you are looking for but pls just try it): https://www.mangago.me/read-manga/kimi_no_yoru_ni_fureru/
Zankoku na Kami ga Shihai suru(I’m low key out off reds rn so just read ts peak): https://www.mangago.me/read-manga/zankoku_na_kami_ga_shihai_suru/
I dare you(this is the type of story that encapsulates the saying I’m not stuck in here with you you’re stuck in here with ME. Like sometimes I wonder what these “bullies” did in their past lives for god to put them on the same earth as my mc and also this one is not Bl but it is really really good): https://www.mangago.me/read-manga/i_dare_you/
My brain can’t seem to come up with any more sooo…
I hope this helps(づ ̄ ³ ̄)づ
Yang Il-woo and I : https://www.mangago.me/read-manga/yang_il_woo_and_i/

Heya! I'm looking for a recs that include school bullying! Mainly looking for BL, and something set in school-life! (I don't mind twisted ones! or non-fluff) smth sadistic lmao.