Question for people who know about witchcraft/symbolic artifacts.?

I'm not sure what the best idea would be, but since death is inevitable, and it never ends, perhaps something related to an infinity sign (I forget what it's called now). I wouldn't use an ahnk as mentioned above because in Egypt that's a sign for eternal life- not so much death. There really isn't a lot that is truely linked to "dark" magick, as magick is really neither light nor dark. I'd almost say to make something up, or use an older text and manipulate it to create what you need.