well from what i get it is that vanilla is just you and your partner loving eachother and no other dudes or whatever
so basically
consensual (bd)sm just more extreme
thx for the suggestions @Finsit theyre pretty nice
youre a stalker ish guy and youve fallen in love with xxx (your neighbor, sister, colleague, i dunno what) but she doesnt like you that much back
and thus you abduct hers and try to stockholm syndrome while unleashing your sadistic desire on her so that she loves you back (and not just your cock)
or
you have a girlfriend and shes a normal person but you have your dark side and you want to subject her to your sadistic desires
trainer games are good but i feel like most of em miss that "love" feel. its usually just a master-slave relation where the master just uses the slave
I guess any slave trainer on the same vein as Slave Maker game would also work, as well as most of the Selectacorp games/stories.
Maybe Incubus City too. It does fit in your list but on the victim turned to lover it will be light.