Desensitization
The vampire with this affliction is a virtual emotional amputee. As a derangement, desensitization inhibits the vampire's ability to feel any sort of strong emotion whatsoever, whether joy, sadness, anger or love. The afflicted just can't make the appropriate neural connections (well, for want of a better term).
The power of Presence or the blood bond can still hod a vampire so afflicted in check, but even though such supernatural compulsion governs teh vampire's actions, it has less of an effect on her psyche. Even when blood bound, the vampire goes through the motions of love and devotion like a distracted actor half-heartedly playing a part. She will still throw herself in front of a car to save her "loved one," but she will do so without so much as a word, a tear or a smile. When she frenzies, she does so in a chillingly silent paroxysm of violence; when struck with the Rotschreck, she scuttles away like a cockroach instinctively fleeing the light.
Vampires with this derangement find it difficult to truly believe in their own ideals, and so make all Humanity, Path, Conscience or Conviction rolls at +2 difficulty. They also suffer a one-die penalty to all Social dice pools that require some show of emotion or warmth, and cannot purchase the Performance Ability at all.
