I would personally love to see a Slayer pin happen. I would concede that while Slayer is huge and legendary in the metal world, they are not as mainstream as any of the bands Stern has licensed previously. Does this matter at the end of the day? Maybe? I remember when Stern first asked about what metal bands people liked on a Facebook thread. I, of course, mentioned Meshuggah. I would say that proper realization of a Slayer pin would certainly include some evil imagery and call outs. I can't imagine the art being any more gory than TWD. Tom Araya yelling at you to "get the extra ball" would be a riot. They played up the Satanic thing in the 80's. I'm pretty sure they have said as much in interviews, even. While Kerry King seems like imposing guy, I don't think he'd sacrifice a goat.