Source: Book of Spirits p146
This insidious Numen allows a spirit to rob hours of sleep of its victims. Spend one point of Essence and roll Power + Finesse – the target’s Stamina + Supernatural Tolerance. Each success represents an hour’s worth of sleep lost. These can only be recovered through normal sleep. After the spirit eats six hours of the target’s sleep, the target begins suffering the effects of fatigue (see the World of Darkness Rulebook, p. 179) as if he had not slept in 24 hours. Each six successes beyond this means the target loses another day’s sleep, and he suffers a cumulative –1 die penalty to all dice pools and must make Stamina + Resolve rolls or fall asleep. A person may only lose a number of days worth of sleep equal to the lowest of his Stamina or Resolve before passing out.