Hunger gives powers

"Speaking of," I said, "how much do you know about the White Court?"
"Oh, the usual," Bob said, which meant he knew plenty.
"I saw Thomas get real weird tonight," I said. "I don't know how to describe it, exactly. But Justine was there, and she said that he was freezing and that it worried her. Then he hit her with some kind of mind-magic hypnosis whammy, and zoned her out entirely."
"He was Hungry," Bob said. "I mean, capital H kind of Hungry. The Hunger is a kind of... I don't know. Symbiotic spirit, inside a White Court vamp. They're born with it."
"Ah," I said. "That's where they get the strength and powers and stuff."
"Among them nigh-immortality," Bob said. "But it don't happen for free. That's why they do the whole feeding thing. The Hunger needs it to survive."


Blood Rites Chapter 5, Page 37-38