Quiet Menace

There are many kinds of restless spirits out there and this one knows how to strike where it hurts. Unlike the Unquiet Ones, it is very hard to spot that one is nearby as the undead tend to be active at night, when it is incredibly hard to distinguish shadows from darkness. Menaces are haunting and still, the colour of the deepest ink. They make no sound and no threats, instead they can latch onto a person who stands in their way and when you notice you have one more shadow than you should have - it might already be to late. Their quiet whispers might already alter how you behave in day to day life, making your nights even more restless with frequent episodes of nightwalking.
Unlike the other supernatural spirits, the shadows need to be send after someone like a curse, by a skilled shaman or magician. If you make someone powerful very angry, they do tend to have weapons that do not leave any traces. Instead they will make you self destruct. Every magic does have its cost however.
There is a small chance of reverting what's being done to you, but not many people with powerful enemies also have powerful friends. And who would want to associate with someone so obviously cursed? Once a shadow latches onto you, it is hard to get rid off in the broad daylight.