Toxic BL

Seme is a psycho who may just kill someone for looking at him wrong.
He manipulates the uke, deliberately hurts him by sleeping with his lover and eventually rapes him.
Despite this, Taeui is too soft-hearted of a person to actually hate him. In fact he might... Love him?

Omegaverse story.
Seme repeatedly rapes the uke, uses his debts to make him his personal prostitute and treats him like a toy. The uke eventually breaks psychologically, and only then does the seme realise he's in love with him and regrets how he treated him.
However, despite all the horrible shit the seme put the uke through, it's clear they'll still end up together.

Incredibly toxic, dark and twisted.
Uke is in love with the seme, but the seme uses him like a fuck toy and breaks his heart repeatedly. Once the uke finally decides to break out of the cycle and learns some self-respect, the seme turns obsessive and takes him prisoner.

3/5 stars.
Not as toxic as some of the other titles on the list, but there is dubcon and seme is very forceful in bed.