Most of what is in this article can be safely ignored. A lot of the comments are talking about the truth:
If she keeps choosing assholes and abusers then that means she likes assholes abusers. Assholes and abusers turn her on. Nice guys don’t.
And if you do find yourself falling for a girl who likes men like this she won’t stick with you for long. Once she builds herself back up she will let you go because, as a decent guy, you just don’t do it for her.
The simple answer to “how to date a woman who dates assholes” is that you either go full asshole or you walk away.
Personally, I recommend walking away, but the choice is yours.
And especially keep in mind that it’s not your job to fix her or anybody else. Your job is to work on yourself.