I really hope that Tristayne Olliven the necromancer in the new expansion has something to do with zombies.
It would be awesome if he had some ability that went like
"May replace any open group with zombies at setup as long as Tristayne is the master"
and then if he had something like "When a zombie is defeated within 5 spaces of Tristayne place a wound marker there, at the start of next overlord turn, a zombie is spawned in the nearest space to the wound marker."
and then maybe "Death pulse: Heal 2 health to every monster in a 5 space range"
I just really hope that we get to see some of the worse monsters made better by the new agents, and I think this would be a super fun way to do it. It would really make the zombies feel like zombies, and zombies are so awful, allowing them to come back I don't think would over power things too bad as long as Tristayne had low health and maybe one grey die.