The basic idea: give revs a skill to inflict Shambling Plague directly, zombie-bite-like. The vampire and werewolf archetypes are well-represented in the rev skill tree, but zambahz less so; it's hard to spread barhah via plague rats alone.
Some different ways this could work:
%chance to inflict Shambling Plague on attack, OR to directly spawn a Shambling Zombie on kill
applies to Feeding Fangs attack, OR provides a new "Infectious Bite" attack, OR applies to any close-combat attack
child of Plague Upon Thee (because plague) OR Shadow of the Dust (because zombie)
This should be a Touch attack that can be selected by Fangs (HTH) and Umbral Sword (Melee) users. Child skill of Shadow of the Dust for that undead plague flavour. I suspect it would need a cure (assuming the victim survives the initial attack) along the line of a FAK or specialist drugs.
Is it worth 60 CP though? Would it be appropriate to apply this automatically on any attack, at say 25% chance to occur? Or would it have to be its own 1 AP 5 MP charged attack that is 100% successful on a hit? Or both?