info on a few characters!

Jaehyun he kills, he doesn't talk to anyone until he meets Y/N. From there their lives changes and goes on for an other life time. What will happen when he passes away? What happens when Y/N is comes back into the world again with a new life and new family and y/n doesn't know who Jaehyun is? Will he kill again for her or because it's always been his sport? How will the story end?