A-yun's a Useless Concubine's feed

Can y'alls recommend me a yandere BL? I mean like, with a real literal yandere, not just some sorta half jealous or possessive guy, i mean the generic really sweet, obsessive and scary stalker type you know?

Doesn't matter how thematically heavy or comedic it is, just as long as it's a literal yandere is fine~ (This term is used way too loosely, it's hard to find authentic ones--)