Twiceborn

With this ritual, the necromancer enchants his own body to protect himself from death. If the necromancer is slain, he is revived as a Wight Mage in the province where the ritual was cast, possibly gaining dark insights in the process. For the ritual to work, the province it was cast in must be in friendly hands when the necromancer dies. This spell requires more power to affect large beings and the cost of casting the ritual is increased with the caster's size. Undead, demons, plants, inanimates, pretender gods as well as most monsters that aren't even remotely humanoid (e.g. hydras and sea serpents) cannot be twiceborned.

Text: Illwinter Game Design, via Dom6 Inspector