Male yanderes?

Secret Alliance: https://www.mangago.zone/read-manga/secret_alliance/
Metronome: https://www.mangago.zone/read-manga/metronome/

BL:
https://www.mangago.zone/read-manga/risou_no_koibito/ only male yandere bl I remember. its super sadistic though. the rest I remember reading are all with no consent unfortunately (╯°Д °)╯╧╧

oh wait I barely realized that being stalked upon is also considered no consent LMAO well anyways what I meant was that https://www.mangago.zone/read-manga/risou_no_koibito/ isn't a good recommendation

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

The purple-haired mail character is obsessed with the main protagonist and goes psycho a bunch when on screen.