“To what extent in war when killing the enemy is not enough? When the way you kill is considered for the better, yet seems wrong and bound to threaten the souls of those responsible with damnation? When you kill your enemy but use their spirits to infiltrate their old homes only to kill more of their kin. There is a saying, treat your friends and family with love, but treat your enemy with compassion.
What is left sacred, when humans can murder our kin and parade around in our homes looking like us? For that, let the mountains fall on their spirits and deny them passage to the Hidden Valley I tell you, there is no compassion in what they do. This is not war, it is mass murder. The Gods will cry before this is finished.”
Maugmura - General Elite of the Fifth Column of Stone
Have you or anyone you know ever been accused of a crime you didn’t commit? Been sent to the Hangman knowing you were innocent? Have you ever welcomed the noose to prove it?
If you want to add a "supernatural" touch to your campaign, define the rules of magic and the universe. Make your players comfortable with those rules. Then your new supernatural creatures must then break those rules.