An Advanced Creature Profile by Vincent Groth.  

The Zakra are incorporeal undead, spirits, a mortal soul trapped by nightmarish creatures such as the Shadowed. They appear as they did on their final day of life with a translucent dulled coloration of their true lives. Zakra live out their final day on repeat from midnight till death. 

Zakra are eternal creatures bound to the source of their curse. They can rip the lifeforce from the living when provoked shortening lives by years, weakening the soul and its connection to the flesh, and causing permanent damage to the living. 

Zakra are used as livestock to nightmares that feed off pain and suffering, feeding on their cycle of living through their final day. Zakra are not hostile and generally pay no attention to mortals unless they try to disrupt their daily reenactment. When disturbed Zakra in an area will swarm the agitator in mass. 

Zakra can be disrupted with divine power whether negative or positive.  Though they will return at the stroke of midnight. Zakra must live out their last day every day. Only when actively driven to hostility or temporarily destroyed will a Zakra deviate.