[SolemnGolem]

Thanks Varyon and Phantasm for the useful answers. I think I have my Ravenloft lich build.

Possession at +0%, with the inverse mechanic that it can only possess corpses (or active undead at a successful Will roll - meaning it usually wins against Zombies but things like Vampires might be a bit more challenging). Then a +40% for Ranged (and RAW even specifies Possession as an appropriate use). Edit: Another confounding factor is that the lich can possess a zombie, then get killed as the zombie, and still not die - this is different from Possession normally since death of the vessel usually kills the possessor as well. However, I'm not going to change the cost of Possession just for this trait, since the lich already bought Unkillable, specifically to get around this sort of problem.

This means the lich can leap from corpse to corpse without having to trigger a Reincarnation by "dying". It also means that you don't have to create a new form with entirely new abilities, the way you would with Reincarnation.

Reincarnation seems to be a good defense against adventurers if they get a lucky encounter against you and do you in. Whereas Ranged Possession seems to be a wholly applicable combat use - to disorient and confuse your foes and allow you to continue striking from different bodies.