I also can't scream, which is a sluagh particularity, and I subsist on half-bad food. Church bells make me sneeze, a horseshoe over a door makes me very uncomfortable with going inside, and any kind of cold iron will quite painfully murder me or make an effective bond, depending on someone's inclinations and the way the metal is fashioned. I think that's the extent of my supernatural weaknesses, all of which are fairly common knowledge to folklore.