I saw a Killer x Law doujinshi. It was really good. I think Killer would be very kind and loving but get easily annoyed with Law's attitude. He would be gentle and compassionate but quickly lose his temper over what Law says. Then, he would apologize and make up for it with massages and going back to being gentle. Idk. I just see him in that way. I love it. And Law would be very into it. Though, he would deny it. Plus, Killer saying sweet things to him would embarrass Law, causing him to be rude and that would lead Killer to his quick change. It's a nice concept.