The Soldier - In the line of fire there's always civilians, and hostages to recuse. Some even grow attached to the person that recuses them. But when he rejects you saying "I'm sorry but I don't think you'll fit my type of girl" you pry further trying to find out what it is that is his type. Turns out he's into a more dominant and master-like relationship than traditional or modern relationships. He leaves a lot for his job requires it, but when he's home he takes his frustration out on her, both sexually and violently (being rough, not hurting for the sake of hurting)
Deathproof - His car may be deathproof but once he finds a girl who actually wants him to hurt her he couldn't help but oblige to take her home and do unspeakable things to her. Based on the movie Deathproof by Quentin Tarantino.
Doctor Weinstein - Experimental drugs have their effects on people. So when he finds out that a patient is a runaway he takes the opportunity to kidnap her and use her to test out the drugs upon. To see her reactions, only to find out more and more how he enjoys seeing her tied up in his basement.
Zombie apocalypse - So you've been alone for the longest time, upon finally meeting someone, he refuses to let you tag along with him. Even if she might be the last woman he'll meet, he explains to her that she'd be a liability. After getting to know each other does he finally accept her to tag along. But as she gets to know him she finds out how twisted a personality he has and what he did before the apocalypse. That bit of information will have to wait till I get someone interested to start this one.
This thread is a work in progress and I will be updating it frequently. Feel free to post interest in the thread. I don't mind. You can also PM me if you have ideas or like any of mine.