i would say AJ is a zombie, or maybe a ghoul/ghast.
under-appreciated, but solid and dependable. you couldn't have an undead takeover without them.
I'm fond of Sin-Eaters, myself. Though they're probably too specific of a reference. Which is a shame, because they are so much fun.
Essentially people who have a sort of symbiotic possession deal with a ghost/spirit/avatar of Death. They're a World of Darkness splat.