The Curse is a Manifestation in the arsenal of a Sin-Eater which allows the geist to touch a victim with its plasm. It doesn’t inflict direct damage, but makes life for its victim really unpleasant in drawing events near that correspondent to the used plasm. Although the geist is only the catalyst for the events that unfold during the curse, other supernaturals are able to trace it back to him.
The victim begins to lose willpower
The victim is temporally transferred into Twilight