Vacant are Sin-Eaters without a Geist, having destroyed or lost their complementary part. In contrast to Wretched, who have simply lost any contact to their Geist, they still have a Synergy rating of 1, but cannot empower Ceremonies or utilize any Key or Manifestation.
Most Vacant are driven insane by the gaping hole where the Geist used to be. Most comitt suicide or try to attract another Geist. Since most Geist avoid former Sin-Eaters out of fear and distrust, most drop back to extracting a Geist from another Sin-Eater via blasphemous Ceremonies that are of great concern to Sin-Eaters everywhere. Even if a second bargain can be made, however, a Vacant immediatly becomes a Wretched and has little chances to escape this state.
- , p.243