It's also a world famous band who, I'd assume, hold multiple trademarks on their name. There is a substantial amount other trademarks on the word which you'd have to tiptoe through too.
Hmm.. I see but slayer seems like it could stand alone as a solid noun irrelevant to the band, because the name is not that unique, as opposed to something like MegaDeth(.org) which was dropped today coincidentally.