The Mark of Cain, as in the curse God put on the first killer. [url=https://img0.etsystatic.com/034/0/6099470/il_fullxfull.594093418_9vk3.jpg]The Mark[/url] Can be placed almost anywhere on the body though mostly commonly on the inside of the right forearm. It prevents the marked from dying or being injured, though they're an exile to their human kin and eventually become a demon. The Mark may be passed along to another killer, though if the marked has already become a demon than they will remain thus.  It's a curse that protects the victim :p

And character sheets. Mine's already up.