There have always been readers throughout history who have been drawn to villains.

She had no recollection, later, of having decided what to do next, or of having hunted for something to wear, but somehow she was hurrying down the stairs, dressed in shadowhunter gear, the letter in one hand and the chain with the ring clasped hastily around her throat.

Jace whistled. "Raphael is really having an exceptionally bad night." -Jace, pg.283-

Family is more than blood

I shall charm him with such force that when I am done, he will be left lying limply on the ground, trying to remember his own name.

Write what you want to read. So many people think they need to write a particular kind of book, or imitate a successful style, in order to be published. I've known people who felt they had to model their book on existing blockbusters, or write in a genre that's supposed to be "hot right now" in order to get agents and publishers interested. But if you're writing in a genre you don't like, or modeling yourself on a book you don't respect, it'll show through. You're your first, most important reader, so write the book that reader really wants to read.

Have a little faith in my magic fingers