Template ideas for a pathfinder incorporeal creature?

[MonkeySage]

I'm trying to come up with ideas to incorporate Taint, and the div lord Ahriman into the same campaign...

My idea is that Ahriman will appear in my game from time to time in the incorporeal form of people who have died, particularly deaths caused by evil acts, or in the form of evil characters who have died.(Kind of like The First, in buffyverse)

These aspects that he takes would ideally have all the stats of the person he's taking the form of, just without a strength or con score. (Perhaps his touch attack causes taint, rather than damage)

Encounters with these aspects may or may not be combat encounters; the aspect is a threat mainly because of their powers of persuasion.

So I was hoping to get ideas for a template that might reflect my intent. Something that I could apply to almost any creature.

Type... Not sure whether to count them as divs or undead- they aren't really ghosts...