Necrophilia
Description: This ritual causes a mortal to experience a supernatural sexual attraction to corpses, which will drive the victim to consummate a union with the dead. While under the influence of this curse, the victim will fantasize about intercourse with corpses and actively seek out dead bodies according to his or her natural sexuality and moral limitations. Necrophilia is not a healthy activity physically, mentally or legally; victims of this curse may be subject to other secondary difficulties including: legal action, the rejection of the victim by his or her associates and possible bacterial or viral infections. Obviously, this ritual is used as a punishment for mortals who have angered the necromancer.
Origin: This kind of ritual is ancient and many variants exist.
Ingredients: The mummified genitalia of a deceased sex offender and cantharides (a.k.a: Spanish Fly), a toxic preparation of the crushed, dried bodies of this Southern European blister beetle, commonly used as an aphrodisiac.
Casting: The caster begins the ritual by placing the fetish in his right hand and speaking of his power over the former owner, often by recounting how he the necromancer emasculated the deceased by severing the source of his power. Then the caster places the fetish in his left hand and sprinkles the mummified genitalia with cantharides while invoking the power of the fetish to curse the victim for his or her transgressions against the necromancer.
System: The ritual takes five minutes to cast, at a difficulty of four (4). The effects of this ritual last one night, disappearing as the sun rises. The mortal (it doesn't work on vampires) must be present when the ritual is invoked, and the fetish must be placed somewhere on his or her person (in a pocket, around the victim's neck on a thong or concealed as something else the victim possesses).
Reference: This ritual's parallel is the thaumaturgic 'Devil's Touch' ritual, found on pg.184 of the Masquerade.