Lanefan
Victoria Rules
Does your campaign have any means of destroying or unmaking the soul/spirit? If yes, True Res comes off the table.
Does your BBEG Wizard have access to Wish? If yes, depending what you allow Wish to do in your campaign, problem solved: simply have him Wish that the spirits of the deceased can never again inhabit a body on the Prime Material plane under any circumstances.
Does your BBEG Wizard have access to Wish? If yes, depending what you allow Wish to do in your campaign, problem solved: simply have him Wish that the spirits of the deceased can never again inhabit a body on the Prime Material plane under any circumstances.